mtc-bench

#!/usr/bin/env perl

# This chunk of stuff was generated by App::FatPacker. To find the original
# file's code, look for the end of this BEGIN block or the string 'FATPACK'
BEGIN {
my %fatpacked;

$fatpacked{"Text/CSV.pm"} = '#line '.(1+__LINE__).' "'.__FILE__."\"\n".<<'TEXT_CSV';
  package Text::CSV;
  
  
  use strict;
  use Exporter;
  use Carp ();
  use vars qw( $VERSION $DEBUG @ISA @EXPORT_OK %EXPORT_TAGS );
  @ISA = qw( Exporter );
  
  BEGIN {
      $VERSION = '2.04';
      $DEBUG   = 0;
  }
  
  # if use CSV_XS, requires version
  my $Module_XS  = 'Text::CSV_XS';
  my $Module_PP  = 'Text::CSV_PP';
  my $XS_Version = '1.53';
  
  my $Is_Dynamic = 0;
  
  my @PublicMethods = qw/
      version error_diag error_input
      known_attributes
      PV IV NV CSV_TYPE_PV CSV_TYPE_IV CSV_TYPE_NV
      CSV_FLAGS_IS_QUOTED CSV_FLAGS_IS_BINARY CSV_FLAGS_ERROR_IN_FIELD CSV_FLAGS_IS_MISSING
  /;
  
  %EXPORT_TAGS = (
      CONSTANTS => [qw(
          CSV_FLAGS_IS_QUOTED
          CSV_FLAGS_IS_BINARY
          CSV_FLAGS_ERROR_IN_FIELD
          CSV_FLAGS_IS_MISSING
          CSV_TYPE_PV
          CSV_TYPE_IV
          CSV_TYPE_NV
      )],
  );
  @EXPORT_OK = (qw(csv PV IV NV), @{$EXPORT_TAGS{CONSTANTS}});
  
  #
  
  # Check the environment variable to decide worker module.
  
  unless ($Text::CSV::Worker) {
      $Text::CSV::DEBUG and  Carp::carp("Check used worker module...");
  
      if ( exists $ENV{PERL_TEXT_CSV} ) {
          if ($ENV{PERL_TEXT_CSV} eq '0' or $ENV{PERL_TEXT_CSV} eq 'Text::CSV_PP') {
              _load_pp() or Carp::croak $@;
          }
          elsif ($ENV{PERL_TEXT_CSV} eq '1' or $ENV{PERL_TEXT_CSV} =~ /Text::CSV_XS\s*,\s*Text::CSV_PP/) {
              _load_xs() or _load_pp() or Carp::croak $@;
          }
          elsif ($ENV{PERL_TEXT_CSV} eq '2' or $ENV{PERL_TEXT_CSV} eq 'Text::CSV_XS') {
              _load_xs() or Carp::croak $@;
          }
          else {
              Carp::croak "The value of environmental variable 'PERL_TEXT_CSV' is invalid.";
          }
      }
      else {
          _load_xs() or _load_pp() or Carp::croak $@;
      }
  
  }
  
  sub new { # normal mode
      my $proto = shift;
      my $class = ref($proto) || $proto;
  
      unless ( $proto ) { # for Text::CSV_XS/PP::new(0);
          return eval qq| $Text::CSV::Worker\::new( \$proto ) |;
      }
  
      #if (ref $_[0] and $_[0]->{module}) {
      #    Carp::croak("Can't set 'module' in non dynamic mode.");
      #}
  
      if ( my $obj = $Text::CSV::Worker->new(@_) ) {
          $obj->{_MODULE} = $Text::CSV::Worker;
          bless $obj, $class;
          return $obj;
      }
      else {
          return;
      }
  
  
  }
  
  sub csv {
      if (@_ && ref $_[0] eq __PACKAGE__ or ref $_[0] eq __PACKAGE__->backend) {
          splice @_, 0, 0, "csv";
      }
      my $backend = __PACKAGE__->backend;
      no strict 'refs';
      &{"$backend\::csv"}(@_);
  }
  
  sub require_xs_version { $XS_Version; }
  
  
  sub module {
      my $proto = shift;
      return   !ref($proto)            ? $Text::CSV::Worker
             :  ref($proto->{_MODULE}) ? ref($proto->{_MODULE}) : $proto->{_MODULE};
  }
  
  *backend = *module;
  
  
  sub is_xs {
      return $_[0]->module eq $Module_XS;
  }
  
  
  sub is_pp {
      return $_[0]->module eq $Module_PP;
  }
  
  
  sub is_dynamic { $Is_Dynamic; }
  
  sub _load_xs { _load($Module_XS, $XS_Version) }
  
  sub _load_pp { _load($Module_PP) }
  
  sub _load {
      my ($module, $version) = @_;
      $version ||= '';
  
      $Text::CSV::DEBUG and Carp::carp "Load $module.";
  
      eval qq| use $module $version |;
  
      return if $@;
  
      push @Text::CSV::ISA, $module;
      $Text::CSV::Worker = $module;
  
      local $^W;
      no strict qw(refs);
  
      for my $method (@PublicMethods) {
          *{"Text::CSV::$method"} = \&{"$module\::$method"};
      }
      return 1;
  }
  
  
  
  1;
  __END__
  
  =pod
  
  =head1 NAME
  
  Text::CSV - comma-separated values manipulator (using XS or PurePerl)
  
  
  =head1 SYNOPSIS
  
  This section is taken from Text::CSV_XS.
  
   # Functional interface
   use Text::CSV qw( csv );
  
   # Read whole file in memory
   my $aoa = csv (in => "data.csv");    # as array of array
   my $aoh = csv (in => "data.csv",
                  headers => "auto");   # as array of hash
  
   # Write array of arrays as csv file
   csv (in => $aoa, out => "file.csv", sep_char => ";");
  
   # Only show lines where "code" is odd
   csv (in => "data.csv", filter => { code => sub { $_ % 2 }});
  
   # Object interface
   use Text::CSV;
  
   my @rows;
   # Read/parse CSV
   my $csv = Text::CSV->new ({ binary => 1, auto_diag => 1 });
   open my $fh, "<:encoding(utf8)", "test.csv" or die "test.csv: $!";
   while (my $row = $csv->getline ($fh)) {
       $row->[2] =~ m/pattern/ or next; # 3rd field should match
       push @rows, $row;
       }
   close $fh;
  
   # and write as CSV
   open $fh, ">:encoding(utf8)", "new.csv" or die "new.csv: $!";
   $csv->say ($fh, $_) for @rows;
   close $fh or die "new.csv: $!";
  
  =head1 DESCRIPTION
  
  Text::CSV is a thin wrapper for L<Text::CSV_XS>-compatible modules now.
  All the backend modules provide facilities for the composition and
  decomposition of comma-separated values. Text::CSV uses Text::CSV_XS
  by default, and when Text::CSV_XS is not available, falls back on
  L<Text::CSV_PP>, which is bundled in the same distribution as this module.
  
  =head1 CHOOSING BACKEND
  
  This module respects an environmental variable called C<PERL_TEXT_CSV>
  when it decides a backend module to use. If this environmental variable
  is not set, it tries to load Text::CSV_XS, and if Text::CSV_XS is not
  available, falls back on Text::CSV_PP;
  
  If you always don't want it to fall back on Text::CSV_PP, set the variable
  like this (C<export> may be C<setenv>, C<set> and the likes, depending
  on your environment):
  
    > export PERL_TEXT_CSV=Text::CSV_XS
  
  If you prefer Text::CSV_XS to Text::CSV_PP (default), then:
  
    > export PERL_TEXT_CSV=Text::CSV_XS,Text::CSV_PP
  
  You may also want to set this variable at the top of your test files, in order
  not to be bothered with incompatibilities between backends (you need to wrap
  this in C<BEGIN>, and set before actually C<use>-ing Text::CSV module, as it
  decides its backend as soon as it's loaded):
  
    BEGIN { $ENV{PERL_TEXT_CSV}='Text::CSV_PP'; }
    use Text::CSV;
  
  =head1 NOTES
  
  This section is also taken from Text::CSV_XS.
  
  =head2 Embedded newlines
  
  B<Important Note>:  The default behavior is to accept only ASCII characters
  in the range from C<0x20> (space) to C<0x7E> (tilde).   This means that the
  fields can not contain newlines. If your data contains newlines embedded in
  fields, or characters above C<0x7E> (tilde), or binary data, you B<I<must>>
  set C<< binary => 1 >> in the call to L</new>. To cover the widest range of
  parsing options, you will always want to set binary.
  
  But you still have the problem  that you have to pass a correct line to the
  L</parse> method, which is more complicated from the usual point of usage:
  
   my $csv = Text::CSV->new ({ binary => 1, eol => $/ });
   while (<>) {		#  WRONG!
       $csv->parse ($_);
       my @fields = $csv->fields ();
       }
  
  this will break, as the C<while> might read broken lines:  it does not care
  about the quoting. If you need to support embedded newlines,  the way to go
  is to  B<not>  pass L<C<eol>|/eol> in the parser  (it accepts C<\n>, C<\r>,
  B<and> C<\r\n> by default) and then
  
   my $csv = Text::CSV->new ({ binary => 1 });
   open my $fh, "<", $file or die "$file: $!";
   while (my $row = $csv->getline ($fh)) {
       my @fields = @$row;
       }
  
  The old(er) way of using global file handles is still supported
  
   while (my $row = $csv->getline (*ARGV)) { ... }
  
  =head2 Unicode
  
  Unicode is only tested to work with perl-5.8.2 and up.
  
  See also L</BOM>.
  
  The simplest way to ensure the correct encoding is used for  in- and output
  is by either setting layers on the filehandles, or setting the L</encoding>
  argument for L</csv>.
  
   open my $fh, "<:encoding(UTF-8)", "in.csv"  or die "in.csv: $!";
  or
   my $aoa = csv (in => "in.csv",     encoding => "UTF-8");
  
   open my $fh, ">:encoding(UTF-8)", "out.csv" or die "out.csv: $!";
  or
   csv (in => $aoa, out => "out.csv", encoding => "UTF-8");
  
  On parsing (both for  L</getline> and  L</parse>),  if the source is marked
  being UTF8, then all fields that are marked binary will also be marked UTF8.
  
  On combining (L</print>  and  L</combine>):  if any of the combining fields
  was marked UTF8, the resulting string will be marked as UTF8.  Note however
  that all fields  I<before>  the first field marked UTF8 and contained 8-bit
  characters that were not upgraded to UTF8,  these will be  C<bytes>  in the
  resulting string too, possibly causing unexpected errors.  If you pass data
  of different encoding,  or you don't know if there is  different  encoding,
  force it to be upgraded before you pass them on:
  
   $csv->print ($fh, [ map { utf8::upgrade (my $x = $_); $x } @data ]);
  
  For complete control over encoding, please use L<Text::CSV::Encoded>:
  
   use Text::CSV::Encoded;
   my $csv = Text::CSV::Encoded->new ({
       encoding_in  => "iso-8859-1", # the encoding comes into   Perl
       encoding_out => "cp1252",     # the encoding comes out of Perl
       });
  
   $csv = Text::CSV::Encoded->new ({ encoding  => "utf8" });
   # combine () and print () accept *literally* utf8 encoded data
   # parse () and getline () return *literally* utf8 encoded data
  
   $csv = Text::CSV::Encoded->new ({ encoding  => undef }); # default
   # combine () and print () accept UTF8 marked data
   # parse () and getline () return UTF8 marked data
  
  =head2 BOM
  
  BOM  (or Byte Order Mark)  handling is available only inside the L</header>
  method.   This method supports the following encodings: C<utf-8>, C<utf-1>,
  C<utf-32be>, C<utf-32le>, C<utf-16be>, C<utf-16le>, C<utf-ebcdic>, C<scsu>,
  C<bocu-1>, and C<gb-18030>. See L<Wikipedia|https://en.wikipedia.org/wiki/Byte_order_mark>.
  
  If a file has a BOM, the easiest way to deal with that is
  
   my $aoh = csv (in => $file, detect_bom => 1);
  
  All records will be encoded based on the detected BOM.
  
  This implies a call to the  L</header>  method,  which defaults to also set
  the L</column_names>. So this is B<not> the same as
  
   my $aoh = csv (in => $file, headers => "auto");
  
  which only reads the first record to set  L</column_names>  but ignores any
  meaning of possible present BOM.
  
  =head1 METHODS
  
  This section is also taken from Text::CSV_XS.
  
  =head2 version
  
  (Class method) Returns the current module version.
  
  =head2 new
  
  (Class method) Returns a new instance of class Text::CSV. The attributes
  are described by the (optional) hash ref C<\%attr>.
  
   my $csv = Text::CSV->new ({ attributes ... });
  
  The following attributes are available:
  
  =head3 eol
  
   my $csv = Text::CSV->new ({ eol => $/ });
             $csv->eol (undef);
   my $eol = $csv->eol;
  
  The end-of-line string to add to rows for L</print> or the record separator
  for L</getline>.
  
  When not passed in a B<parser> instance,  the default behavior is to accept
  C<\n>, C<\r>, and C<\r\n>, so it is probably safer to not specify C<eol> at
  all. Passing C<undef> or the empty string behave the same.
  
  When not passed in a B<generating> instance,  records are not terminated at
  all, so it is probably wise to pass something you expect. A safe choice for
  C<eol> on output is either C<$/> or C<\r\n>.
  
  Common values for C<eol> are C<"\012"> (C<\n> or Line Feed),  C<"\015\012">
  (C<\r\n> or Carriage Return, Line Feed),  and C<"\015">  (C<\r> or Carriage
  Return). The L<C<eol>|/eol> attribute cannot exceed 7 (ASCII) characters.
  
  If both C<$/> and L<C<eol>|/eol> equal C<"\015">, parsing lines that end on
  only a Carriage Return without Line Feed, will be L</parse>d correct.
  
  =head3 sep_char
  
   my $csv = Text::CSV->new ({ sep_char => ";" });
           $csv->sep_char (";");
   my $c = $csv->sep_char;
  
  The char used to separate fields, by default a comma. (C<,>).  Limited to a
  single-byte character, usually in the range from C<0x20> (space) to C<0x7E>
  (tilde). When longer sequences are required, use L<C<sep>|/sep>.
  
  The separation character can not be equal to the quote character  or to the
  escape character.
  
  =head3 sep
  
   my $csv = Text::CSV->new ({ sep => "\N{FULLWIDTH COMMA}" });
             $csv->sep (";");
   my $sep = $csv->sep;
  
  The chars used to separate fields, by default undefined. Limited to 8 bytes.
  
  When set, overrules L<C<sep_char>|/sep_char>.  If its length is one byte it
  acts as an alias to L<C<sep_char>|/sep_char>.
  
  =head3 quote_char
  
   my $csv = Text::CSV->new ({ quote_char => "'" });
           $csv->quote_char (undef);
   my $c = $csv->quote_char;
  
  The character to quote fields containing blanks or binary data,  by default
  the double quote character (C<">).  A value of undef suppresses quote chars
  (for simple cases only). Limited to a single-byte character, usually in the
  range from  C<0x20> (space) to  C<0x7E> (tilde).  When longer sequences are
  required, use L<C<quote>|/quote>.
  
  C<quote_char> can not be equal to L<C<sep_char>|/sep_char>.
  
  =head3 quote
  
   my $csv = Text::CSV->new ({ quote => "\N{FULLWIDTH QUOTATION MARK}" });
               $csv->quote ("'");
   my $quote = $csv->quote;
  
  The chars used to quote fields, by default undefined. Limited to 8 bytes.
  
  When set, overrules L<C<quote_char>|/quote_char>. If its length is one byte
  it acts as an alias to L<C<quote_char>|/quote_char>.
  
  This method does not support C<undef>.  Use L<C<quote_char>|/quote_char> to
  disable quotation.
  
  =head3 escape_char
  
   my $csv = Text::CSV->new ({ escape_char => "\\" });
           $csv->escape_char (":");
   my $c = $csv->escape_char;
  
  The character to  escape  certain characters inside quoted fields.  This is
  limited to a  single-byte  character,  usually  in the  range from  C<0x20>
  (space) to C<0x7E> (tilde).
  
  The C<escape_char> defaults to being the double-quote mark (C<">). In other
  words the same as the default L<C<quote_char>|/quote_char>. This means that
  doubling the quote mark in a field escapes it:
  
   "foo","bar","Escape ""quote mark"" with two ""quote marks""","baz"
  
  If  you  change  the   L<C<quote_char>|/quote_char>  without  changing  the
  C<escape_char>,  the  C<escape_char> will still be the double-quote (C<">).
  If instead you want to escape the  L<C<quote_char>|/quote_char> by doubling
  it you will need to also change the  C<escape_char>  to be the same as what
  you have changed the L<C<quote_char>|/quote_char> to.
  
  Setting C<escape_char> to C<undef> or C<""> will completely disable escapes
  and is greatly discouraged. This will also disable C<escape_null>.
  
  The escape character can not be equal to the separation character.
  
  =head3 binary
  
   my $csv = Text::CSV->new ({ binary => 1 });
           $csv->binary (0);
   my $f = $csv->binary;
  
  If this attribute is C<1>,  you may use binary characters in quoted fields,
  including line feeds, carriage returns and C<NULL> bytes. (The latter could
  be escaped as C<"0>.) By default this feature is off.
  
  If a string is marked UTF8,  C<binary> will be turned on automatically when
  binary characters other than C<CR> and C<NL> are encountered.   Note that a
  simple string like C<"\x{00a0}"> might still be binary, but not marked UTF8,
  so setting C<< { binary => 1 } >> is still a wise option.
  
  =head3 strict
  
   my $csv = Text::CSV->new ({ strict => 1 });
           $csv->strict (0);
   my $f = $csv->strict;
  
  If this attribute is set to C<1>, any row that parses to a different number
  of fields than the previous row will cause the parser to throw error 2014.
  
  =head3 skip_empty_rows
  
   my $csv = Text::CSV->new ({ skip_empty_rows => 1 });
           $csv->skip_empty_rows ("eof");
   my $f = $csv->skip_empty_rows;
  
  This attribute defines the behavior for empty rows:  an L</eol> immediately
  following the start of line. Default behavior is to return one single empty
  field.
  
  This attribute is only used in parsing.  This attribute is ineffective when
  using L</parse> and L</fields>.
  
  Possible values for this attribute are
  
  =over 2
  
  =item 0 | undef
  
   my $csv = Text::CSV->new ({ skip_empty_rows => 0 });
   $csv->skip_empty_rows (undef);
  
  No special action is taken. The result will be one single empty field.
  
  =item 1 | "skip"
  
   my $csv = Text::CSV->new ({ skip_empty_rows => 1 });
   $csv->skip_empty_rows ("skip");
  
  The row will be skipped.
  
  =item 2 | "eof" | "stop"
  
   my $csv = Text::CSV->new ({ skip_empty_rows => 2 });
   $csv->skip_empty_rows ("eof");
  
  The parsing will stop as if an L</eof> was detected.
  
  =item 3 | "die"
  
   my $csv = Text::CSV->new ({ skip_empty_rows => 3 });
   $csv->skip_empty_rows ("die");
  
  The parsing will stop.  The internal error code will be set to 2015 and the
  parser will C<die>.
  
  =item 4 | "croak"
  
   my $csv = Text::CSV->new ({ skip_empty_rows => 4 });
   $csv->skip_empty_rows ("croak");
  
  The parsing will stop.  The internal error code will be set to 2015 and the
  parser will C<croak>.
  
  =item 5 | "error"
  
   my $csv = Text::CSV->new ({ skip_empty_rows => 5 });
   $csv->skip_empty_rows ("error");
  
  The parsing will fail.  The internal error code will be set to 2015.
  
  =item callback
  
   my $csv = Text::CSV->new ({ skip_empty_rows => sub { [] } });
   $csv->skip_empty_rows (sub { [ 42, $., undef, "empty" ] });
  
  The callback is invoked and its result used instead.  If you want the parse
  to stop after the callback, make sure to return a false value.
  
  The returned value from the callback should be an array-ref. Any other type
  will cause the parse to stop, so these are equivalent in behavior:
  
   csv (in => $fh, skip_empty_rows => "stop");
   csv (in => $fh. skip_empty_rows => sub { 0; });
  
  =back
  
  Without arguments, the current value is returned: C<0>, C<1>, C<eof>, C<die>,
  C<croak> or the callback.
  
  =head3 formula_handling
  
  Alias for L</formula>
  
  =head3 formula
  
   my $csv = Text::CSV->new ({ formula => "none" });
           $csv->formula ("none");
   my $f = $csv->formula;
  
  This defines the behavior of fields containing I<formulas>. As formulas are
  considered dangerous in spreadsheets, this attribute can define an optional
  action to be taken if a field starts with an equal sign (C<=>).
  
  For purpose of code-readability, this can also be written as
  
   my $csv = Text::CSV->new ({ formula_handling => "none" });
           $csv->formula_handling ("none");
   my $f = $csv->formula_handling;
  
  Possible values for this attribute are
  
  =over 2
  
  =item none
  
  Take no specific action. This is the default.
  
   $csv->formula ("none");
  
  =item die
  
  Cause the process to C<die> whenever a leading C<=> is encountered.
  
   $csv->formula ("die");
  
  =item croak
  
  Cause the process to C<croak> whenever a leading C<=> is encountered.  (See
  L<Carp>)
  
   $csv->formula ("croak");
  
  =item diag
  
  Report position and content of the field whenever a leading  C<=> is found.
  The value of the field is unchanged.
  
   $csv->formula ("diag");
  
  =item empty
  
  Replace the content of fields that start with a C<=> with the empty string.
  
   $csv->formula ("empty");
   $csv->formula ("");
  
  =item undef
  
  Replace the content of fields that start with a C<=> with C<undef>.
  
   $csv->formula ("undef");
   $csv->formula (undef);
  
  =item a callback
  
  Modify the content of fields that start with a  C<=>  with the return-value
  of the callback.  The original content of the field is available inside the
  callback as C<$_>;
  
   # Replace all formula's with 42
   $csv->formula (sub { 42; });
  
   # same as $csv->formula ("empty") but slower
   $csv->formula (sub { "" });
  
   # Allow =4+12
   $csv->formula (sub { s/^=(\d+\+\d+)$/$1/eer });
  
   # Allow more complex calculations
   $csv->formula (sub { eval { s{^=([-+*/0-9()]+)$}{$1}ee }; $_ });
  
  =back
  
  All other values will give a warning and then fallback to C<diag>.
  
  =head3 decode_utf8
  
   my $csv = Text::CSV->new ({ decode_utf8 => 1 });
           $csv->decode_utf8 (0);
   my $f = $csv->decode_utf8;
  
  This attributes defaults to TRUE.
  
  While I<parsing>,  fields that are valid UTF-8, are automatically set to be
  UTF-8, so that
  
    $csv->parse ("\xC4\xA8\n");
  
  results in
  
    PV("\304\250"\0) [UTF8 "\x{128}"]
  
  Sometimes it might not be a desired action.  To prevent those upgrades, set
  this attribute to false, and the result will be
  
    PV("\304\250"\0)
  
  =head3 auto_diag
  
   my $csv = Text::CSV->new ({ auto_diag => 1 });
           $csv->auto_diag (2);
   my $l = $csv->auto_diag;
  
  Set this attribute to a number between C<1> and C<9> causes  L</error_diag>
  to be automatically called in void context upon errors.
  
  In case of error C<2012 - EOF>, this call will be void.
  
  If C<auto_diag> is set to a numeric value greater than C<1>, it will C<die>
  on errors instead of C<warn>.  If set to anything unrecognized,  it will be
  silently ignored.
  
  Future extensions to this feature will include more reliable auto-detection
  of  C<autodie>  being active in the scope of which the error occurred which
  will increment the value of C<auto_diag> with  C<1> the moment the error is
  detected.
  
  =head3 diag_verbose
  
   my $csv = Text::CSV->new ({ diag_verbose => 1 });
           $csv->diag_verbose (2);
   my $l = $csv->diag_verbose;
  
  Set the verbosity of the output triggered by C<auto_diag>.   Currently only
  adds the current  input-record-number  (if known)  to the diagnostic output
  with an indication of the position of the error.
  
  =head3 blank_is_undef
  
   my $csv = Text::CSV->new ({ blank_is_undef => 1 });
           $csv->blank_is_undef (0);
   my $f = $csv->blank_is_undef;
  
  Under normal circumstances, C<CSV> data makes no distinction between quoted-
  and unquoted empty fields.  These both end up in an empty string field once
  read, thus
  
   1,"",," ",2
  
  is read as
  
   ("1", "", "", " ", "2")
  
  When I<writing>  C<CSV> files with either  L<C<always_quote>|/always_quote>
  or  L<C<quote_empty>|/quote_empty> set, the unquoted  I<empty> field is the
  result of an undefined value.   To enable this distinction when  I<reading>
  C<CSV>  data,  the  C<blank_is_undef>  attribute will cause  unquoted empty
  fields to be set to C<undef>, causing the above to be parsed as
  
   ("1", "", undef, " ", "2")
  
  Note that this is specifically important when loading  C<CSV> fields into a
  database that allows C<NULL> values,  as the perl equivalent for C<NULL> is
  C<undef> in L<DBI> land.
  
  =head3 empty_is_undef
  
   my $csv = Text::CSV->new ({ empty_is_undef => 1 });
           $csv->empty_is_undef (0);
   my $f = $csv->empty_is_undef;
  
  Going one  step  further  than  L<C<blank_is_undef>|/blank_is_undef>,  this
  attribute converts all empty fields to C<undef>, so
  
   1,"",," ",2
  
  is read as
  
   (1, undef, undef, " ", 2)
  
  Note that this affects only fields that are  originally  empty,  not fields
  that are empty after stripping allowed whitespace. YMMV.
  
  =head3 allow_whitespace
  
   my $csv = Text::CSV->new ({ allow_whitespace => 1 });
           $csv->allow_whitespace (0);
   my $f = $csv->allow_whitespace;
  
  When this option is set to true,  the whitespace  (C<TAB>'s and C<SPACE>'s)
  surrounding  the  separation character  is removed when parsing.  If either
  C<TAB> or C<SPACE> is one of the three characters L<C<sep_char>|/sep_char>,
  L<C<quote_char>|/quote_char>, or L<C<escape_char>|/escape_char> it will not
  be considered whitespace.
  
  Now lines like:
  
   1 , "foo" , bar , 3 , zapp
  
  are parsed as valid C<CSV>, even though it violates the C<CSV> specs.
  
  Note that  B<all>  whitespace is stripped from both  start and  end of each
  field.  That would make it  I<more> than a I<feature> to enable parsing bad
  C<CSV> lines, as
  
   1,   2.0,  3,   ape  , monkey
  
  will now be parsed as
  
   ("1", "2.0", "3", "ape", "monkey")
  
  even if the original line was perfectly acceptable C<CSV>.
  
  =head3 allow_loose_quotes
  
   my $csv = Text::CSV->new ({ allow_loose_quotes => 1 });
           $csv->allow_loose_quotes (0);
   my $f = $csv->allow_loose_quotes;
  
  By default, parsing unquoted fields containing L<C<quote_char>|/quote_char>
  characters like
  
   1,foo "bar" baz,42
  
  would result in parse error 2034.  Though it is still bad practice to allow
  this format,  we  cannot  help  the  fact  that  some  vendors  make  their
  applications spit out lines styled this way.
  
  If there is B<really> bad C<CSV> data, like
  
   1,"foo "bar" baz",42
  
  or
  
   1,""foo bar baz"",42
  
  there is a way to get this data-line parsed and leave the quotes inside the
  quoted field as-is.  This can be achieved by setting  C<allow_loose_quotes>
  B<AND> making sure that the L<C<escape_char>|/escape_char> is  I<not> equal
  to L<C<quote_char>|/quote_char>.
  
  =head3 allow_loose_escapes
  
   my $csv = Text::CSV->new ({ allow_loose_escapes => 1 });
           $csv->allow_loose_escapes (0);
   my $f = $csv->allow_loose_escapes;
  
  Parsing fields  that  have  L<C<escape_char>|/escape_char>  characters that
  escape characters that do not need to be escaped, like:
  
   my $csv = Text::CSV->new ({ escape_char => "\\" });
   $csv->parse (qq{1,"my bar\'s",baz,42});
  
  would result in parse error 2025.   Though it is bad practice to allow this
  format,  this attribute enables you to treat all escape character sequences
  equal.
  
  =head3 allow_unquoted_escape
  
   my $csv = Text::CSV->new ({ allow_unquoted_escape => 1 });
           $csv->allow_unquoted_escape (0);
   my $f = $csv->allow_unquoted_escape;
  
  A backward compatibility issue where L<C<escape_char>|/escape_char> differs
  from L<C<quote_char>|/quote_char>  prevents  L<C<escape_char>|/escape_char>
  to be in the first position of a field.  If L<C<quote_char>|/quote_char> is
  equal to the default C<"> and L<C<escape_char>|/escape_char> is set to C<\>,
  this would be illegal:
  
   1,\0,2
  
  Setting this attribute to C<1>  might help to overcome issues with backward
  compatibility and allow this style.
  
  =head3 always_quote
  
   my $csv = Text::CSV->new ({ always_quote => 1 });
           $csv->always_quote (0);
   my $f = $csv->always_quote;
  
  By default the generated fields are quoted only if they I<need> to be.  For
  example, if they contain the separator character. If you set this attribute
  to C<1> then I<all> defined fields will be quoted. (C<undef> fields are not
  quoted, see L</blank_is_undef>). This makes it quite often easier to handle
  exported data in external applications.
  
  =head3 quote_space
  
   my $csv = Text::CSV->new ({ quote_space => 1 });
           $csv->quote_space (0);
   my $f = $csv->quote_space;
  
  By default,  a space in a field would trigger quotation.  As no rule exists
  this to be forced in C<CSV>,  nor any for the opposite, the default is true
  for safety.   You can exclude the space  from this trigger  by setting this
  attribute to 0.
  
  =head3 quote_empty
  
   my $csv = Text::CSV->new ({ quote_empty => 1 });
           $csv->quote_empty (0);
   my $f = $csv->quote_empty;
  
  By default the generated fields are quoted only if they I<need> to be.   An
  empty (defined) field does not need quotation. If you set this attribute to
  C<1> then I<empty> defined fields will be quoted.  (C<undef> fields are not
  quoted, see L</blank_is_undef>). See also L<C<always_quote>|/always_quote>.
  
  =head3 quote_binary
  
   my $csv = Text::CSV->new ({ quote_binary => 1 });
           $csv->quote_binary (0);
   my $f = $csv->quote_binary;
  
  By default,  all "unsafe" bytes inside a string cause the combined field to
  be quoted.  By setting this attribute to C<0>, you can disable that trigger
  for bytes C<< >= 0x7F >>.
  
  =head3 escape_null
  
   my $csv = Text::CSV->new ({ escape_null => 1 });
           $csv->escape_null (0);
   my $f = $csv->escape_null;
  
  By default, a C<NULL> byte in a field would be escaped. This option enables
  you to treat the  C<NULL>  byte as a simple binary character in binary mode
  (the C<< { binary => 1 } >> is set).  The default is true.  You can prevent
  C<NULL> escapes by setting this attribute to C<0>.
  
  When the C<escape_char> attribute is set to undefined,  this attribute will
  be set to false.
  
  The default setting will encode "=\x00=" as
  
   "="0="
  
  With C<escape_null> set, this will result in
  
   "=\x00="
  
  The default when using the C<csv> function is C<false>.
  
  For backward compatibility reasons,  the deprecated old name  C<quote_null>
  is still recognized.
  
  =head3 keep_meta_info
  
   my $csv = Text::CSV->new ({ keep_meta_info => 1 });
           $csv->keep_meta_info (0);
   my $f = $csv->keep_meta_info;
  
  By default, the parsing of input records is as simple and fast as possible.
  However,  some parsing information - like quotation of the original field -
  is lost in that process.  Setting this flag to true enables retrieving that
  information after parsing with  the methods  L</meta_info>,  L</is_quoted>,
  and L</is_binary> described below.  Default is false for performance.
  
  If you set this attribute to a value greater than 9,   then you can control
  output quotation style like it was used in the input of the the last parsed
  record (unless quotation was added because of other reasons).
  
   my $csv = Text::CSV->new ({
      binary         => 1,
      keep_meta_info => 1,
      quote_space    => 0,
      });
  
   my $row = $csv->parse (q{1,,"", ," ",f,"g","h""h",help,"help"});
  
   $csv->print (*STDOUT, \@row);
   # 1,,, , ,f,g,"h""h",help,help
   $csv->keep_meta_info (11);
   $csv->print (*STDOUT, \@row);
   # 1,,"", ," ",f,"g","h""h",help,"help"
  
  =head3 undef_str
  
   my $csv = Text::CSV->new ({ undef_str => "\\N" });
           $csv->undef_str (undef);
   my $s = $csv->undef_str;
  
  This attribute optionally defines the output of undefined fields. The value
  passed is not changed at all, so if it needs quotation, the quotation needs
  to be included in the value of the attribute.  Use with caution, as passing
  a value like  C<",",,,,""">  will for sure mess up your output. The default
  for this attribute is C<undef>, meaning no special treatment.
  
  This attribute is useful when exporting  CSV data  to be imported in custom
  loaders, like for MySQL, that recognize special sequences for C<NULL> data.
  
  This attribute has no meaning when parsing CSV data.
  
  =head3 comment_str
  
   my $csv = Text::CSV->new ({ comment_str => "#" });
           $csv->comment_str (undef);
   my $s = $csv->comment_str;
  
  This attribute optionally defines a string to be recognized as comment.  If
  this attribute is defined,   all lines starting with this sequence will not
  be parsed as CSV but skipped as comment.
  
  This attribute has no meaning when generating CSV.
  
  Comment strings that start with any of the special characters/sequences are
  not supported (so it cannot start with any of L</sep_char>, L</quote_char>,
  L</escape_char>, L</sep>, L</quote>, or L</eol>).
  
  For convenience, C<comment> is an alias for C<comment_str>.
  
  =head3 verbatim
  
   my $csv = Text::CSV->new ({ verbatim => 1 });
           $csv->verbatim (0);
   my $f = $csv->verbatim;
  
  This is a quite controversial attribute to set,  but makes some hard things
  possible.
  
  The rationale behind this attribute is to tell the parser that the normally
  special characters newline (C<NL>) and Carriage Return (C<CR>)  will not be
  special when this flag is set,  and be dealt with  as being ordinary binary
  characters. This will ease working with data with embedded newlines.
  
  When  C<verbatim>  is used with  L</getline>,  L</getline>  auto-C<chomp>'s
  every line.
  
  Imagine a file format like
  
   M^^Hans^Janssen^Klas 2\n2A^Ja^11-06-2007#\r\n
  
  where, the line ending is a very specific C<"#\r\n">, and the sep_char is a
  C<^> (caret).   None of the fields is quoted,   but embedded binary data is
  likely to be present. With the specific line ending, this should not be too
  hard to detect.
  
  By default,  Text::CSV'  parse function is instructed to only know about
  C<"\n"> and C<"\r">  to be legal line endings,  and so has to deal with the
  embedded newline as a real C<end-of-line>,  so it can scan the next line if
  binary is true, and the newline is inside a quoted field. With this option,
  we tell L</parse> to parse the line as if C<"\n"> is just nothing more than
  a binary character.
  
  For L</parse> this means that the parser has no more idea about line ending
  and L</getline> C<chomp>s line endings on reading.
  
  =head3 types
  
  A set of column types; the attribute is immediately passed to the L</types>
  method.
  
  =head3 callbacks
  
  See the L</Callbacks> section below.
  
  =head3 accessors
  
  To sum it up,
  
   $csv = Text::CSV->new ();
  
  is equivalent to
  
   $csv = Text::CSV->new ({
       eol                   => undef, # \r, \n, or \r\n
       sep_char              => ',',
       sep                   => undef,
       quote_char            => '"',
       quote                 => undef,
       escape_char           => '"',
       binary                => 0,
       decode_utf8           => 1,
       auto_diag             => 0,
       diag_verbose          => 0,
       blank_is_undef        => 0,
       empty_is_undef        => 0,
       allow_whitespace      => 0,
       allow_loose_quotes    => 0,
       allow_loose_escapes   => 0,
       allow_unquoted_escape => 0,
       always_quote          => 0,
       quote_empty           => 0,
       quote_space           => 1,
       escape_null           => 1,
       quote_binary          => 1,
       keep_meta_info        => 0,
       strict                => 0,
       skip_empty_rows       => 0,
       formula               => 0,
       verbatim              => 0,
       undef_str             => undef,
       comment_str           => undef,
       types                 => undef,
       callbacks             => undef,
       });
  
  For all of the above mentioned flags, an accessor method is available where
  you can inquire the current value, or change the value
  
   my $quote = $csv->quote_char;
   $csv->binary (1);
  
  It is not wise to change these settings halfway through writing C<CSV> data
  to a stream. If however you want to create a new stream using the available
  C<CSV> object, there is no harm in changing them.
  
  If the L</new> constructor call fails,  it returns C<undef>,  and makes the
  fail reason available through the L</error_diag> method.
  
   $csv = Text::CSV->new ({ ecs_char => 1 }) or
       die "".Text::CSV->error_diag ();
  
  L</error_diag> will return a string like
  
   "INI - Unknown attribute 'ecs_char'"
  
  =head2 known_attributes
  
   @attr = Text::CSV->known_attributes;
   @attr = Text::CSV::known_attributes;
   @attr = $csv->known_attributes;
  
  This method will return an ordered list of all the supported  attributes as
  described above.   This can be useful for knowing what attributes are valid
  in classes that use or extend Text::CSV.
  
  =head2 print
  
   $status = $csv->print ($fh, $colref);
  
  Similar to  L</combine> + L</string> + L</print>,  but much more efficient.
  It expects an array ref as input  (not an array!)  and the resulting string
  is not really  created,  but  immediately  written  to the  C<$fh>  object,
  typically an IO handle or any other object that offers a L</print> method.
  
  For performance reasons  C<print>  does not create a result string,  so all
  L</string>, L</status>, L</fields>, and L</error_input> methods will return
  undefined information after executing this method.
  
  If C<$colref> is C<undef>  (explicit,  not through a variable argument) and
  L</bind_columns>  was used to specify fields to be printed,  it is possible
  to make performance improvements, as otherwise data would have to be copied
  as arguments to the method call:
  
   $csv->bind_columns (\($foo, $bar));
   $status = $csv->print ($fh, undef);
  
  A short benchmark
  
   my @data = ("aa" .. "zz");
   $csv->bind_columns (\(@data));
  
   $csv->print ($fh, [ @data ]);   # 11800 recs/sec
   $csv->print ($fh,  \@data  );   # 57600 recs/sec
   $csv->print ($fh,   undef  );   # 48500 recs/sec
  
  =head2 say
  
   $status = $csv->say ($fh, $colref);
  
  Like L<C<print>|/print>, but L<C<eol>|/eol> defaults to C<$\>.
  
  =head2 print_hr
  
   $csv->print_hr ($fh, $ref);
  
  Provides an easy way  to print a  C<$ref>  (as fetched with L</getline_hr>)
  provided the column names are set with L</column_names>.
  
  It is just a wrapper method with basic parameter checks over
  
   $csv->print ($fh, [ map { $ref->{$_} } $csv->column_names ]);
  
  =head2 combine
  
   $status = $csv->combine (@fields);
  
  This method constructs a C<CSV> record from  C<@fields>,  returning success
  or failure.   Failure can result from lack of arguments or an argument that
  contains an invalid character.   Upon success,  L</string> can be called to
  retrieve the resultant C<CSV> string.  Upon failure,  the value returned by
  L</string> is undefined and L</error_input> could be called to retrieve the
  invalid argument.
  
  =head2 string
  
   $line = $csv->string ();
  
  This method returns the input to  L</parse>  or the resultant C<CSV> string
  of L</combine>, whichever was called more recently.
  
  =head2 getline
  
   $colref = $csv->getline ($fh);
  
  This is the counterpart to  L</print>,  as L</parse>  is the counterpart to
  L</combine>:  it parses a row from the C<$fh>  handle using the L</getline>
  method associated with C<$fh>  and parses this row into an array ref.  This
  array ref is returned by the function or C<undef> for failure.  When C<$fh>
  does not support C<getline>, you are likely to hit errors.
  
  When fields are bound with L</bind_columns> the return value is a reference
  to an empty list.
  
  The L</string>, L</fields>, and L</status> methods are meaningless again.
  
  =head2 getline_all
  
   $arrayref = $csv->getline_all ($fh);
   $arrayref = $csv->getline_all ($fh, $offset);
   $arrayref = $csv->getline_all ($fh, $offset, $length);
  
  This will return a reference to a list of L<getline ($fh)|/getline> results.
  In this call, C<keep_meta_info> is disabled.  If C<$offset> is negative, as
  with C<splice>, only the last  C<abs ($offset)> records of C<$fh> are taken
  into consideration. Parameters C<$offset> and C<$length> are expected to be
  integers. Non-integer values are interpreted as integer without check.
  
  Given a CSV file with 10 lines:
  
   lines call
   ----- ---------------------------------------------------------
   0..9  $csv->getline_all ($fh)         # all
   0..9  $csv->getline_all ($fh,  0)     # all
   8..9  $csv->getline_all ($fh,  8)     # start at 8
   -     $csv->getline_all ($fh,  0,  0) # start at 0 first 0 rows
   0..4  $csv->getline_all ($fh,  0,  5) # start at 0 first 5 rows
   4..5  $csv->getline_all ($fh,  4,  2) # start at 4 first 2 rows
   8..9  $csv->getline_all ($fh, -2)     # last 2 rows
   6..7  $csv->getline_all ($fh, -4,  2) # first 2 of last  4 rows
  
  =head2 getline_hr
  
  The L</getline_hr> and L</column_names> methods work together  to allow you
  to have rows returned as hashrefs.  You must call L</column_names> first to
  declare your column names.
  
   $csv->column_names (qw( code name price description ));
   $hr = $csv->getline_hr ($fh);
   print "Price for $hr->{name} is $hr->{price} EUR\n";
  
  L</getline_hr> will croak if called before L</column_names>.
  
  Note that  L</getline_hr>  creates a hashref for every row and will be much
  slower than the combined use of L</bind_columns>  and L</getline> but still
  offering the same easy to use hashref inside the loop:
  
   my @cols = @{$csv->getline ($fh)};
   $csv->column_names (@cols);
   while (my $row = $csv->getline_hr ($fh)) {
       print $row->{price};
       }
  
  Could easily be rewritten to the much faster:
  
   my @cols = @{$csv->getline ($fh)};
   my $row = {};
   $csv->bind_columns (\@{$row}{@cols});
   while ($csv->getline ($fh)) {
       print $row->{price};
       }
  
  Your mileage may vary for the size of the data and the number of rows. With
  perl-5.14.2 the comparison for a 100_000 line file with 14 columns:
  
              Rate hashrefs getlines
   hashrefs 1.00/s       --     -76%
   getlines 4.15/s     313%       --
  
  =head2 getline_hr_all
  
   $arrayref = $csv->getline_hr_all ($fh);
   $arrayref = $csv->getline_hr_all ($fh, $offset);
   $arrayref = $csv->getline_hr_all ($fh, $offset, $length);
  
  This will return a reference to a list of   L<getline_hr ($fh)|/getline_hr>
  results.  In this call, L<C<keep_meta_info>|/keep_meta_info> is disabled.
  
  =head2 parse
  
   $status = $csv->parse ($line);
  
  This method decomposes a  C<CSV>  string into fields,  returning success or
  failure.   Failure can result from a lack of argument  or the given  C<CSV>
  string is improperly formatted.   Upon success, L</fields> can be called to
  retrieve the decomposed fields. Upon failure calling L</fields> will return
  undefined data and  L</error_input>  can be called to retrieve  the invalid
  argument.
  
  You may use the L</types>  method for setting column types.  See L</types>'
  description below.
  
  The C<$line> argument is supposed to be a simple scalar. Everything else is
  supposed to croak and set error 1500.
  
  =head2 fragment
  
  This function tries to implement RFC7111  (URI Fragment Identifiers for the
  text/csv Media Type) - https://datatracker.ietf.org/doc/html/rfc7111
  
   my $AoA = $csv->fragment ($fh, $spec);
  
  In specifications,  C<*> is used to specify the I<last> item, a dash (C<->)
  to indicate a range.   All indices are C<1>-based:  the first row or column
  has index C<1>. Selections can be combined with the semi-colon (C<;>).
  
  When using this method in combination with  L</column_names>,  the returned
  reference  will point to a  list of hashes  instead of a  list of lists.  A
  disjointed  cell-based combined selection  might return rows with different
  number of columns making the use of hashes unpredictable.
  
   $csv->column_names ("Name", "Age");
   my $AoH = $csv->fragment ($fh, "col=3;8");
  
  If the L</after_parse> callback is active,  it is also called on every line
  parsed and skipped before the fragment.
  
  =over 2
  
  =item row
  
   row=4
   row=5-7
   row=6-*
   row=1-2;4;6-*
  
  =item col
  
   col=2
   col=1-3
   col=4-*
   col=1-2;4;7-*
  
  =item cell
  
  In cell-based selection, the comma (C<,>) is used to pair row and column
  
   cell=4,1
  
  The range operator (C<->) using C<cell>s can be used to define top-left and
  bottom-right C<cell> location
  
   cell=3,1-4,6
  
  The C<*> is only allowed in the second part of a pair
  
   cell=3,2-*,2    # row 3 till end, only column 2
   cell=3,2-3,*    # column 2 till end, only row 3
   cell=3,2-*,*    # strip row 1 and 2, and column 1
  
  Cells and cell ranges may be combined with C<;>, possibly resulting in rows
  with different numbers of columns
  
   cell=1,1-2,2;3,3-4,4;1,4;4,1
  
  Disjointed selections will only return selected cells.   The cells that are
  not  specified  will  not  be  included  in the  returned set,  not even as
  C<undef>.  As an example given a C<CSV> like
  
   11,12,13,...19
   21,22,...28,29
   :            :
   91,...97,98,99
  
  with C<cell=1,1-2,2;3,3-4,4;1,4;4,1> will return:
  
   11,12,14
   21,22
   33,34
   41,43,44
  
  Overlapping cell-specs will return those cells only once, So
  C<cell=1,1-3,3;2,2-4,4;2,3;4,2> will return:
  
   11,12,13
   21,22,23,24
   31,32,33,34
   42,43,44
  
  =back
  
  L<RFC7111|https://datatracker.ietf.org/doc/html/rfc7111> does  B<not>  allow different
  types of specs to be combined   (either C<row> I<or> C<col> I<or> C<cell>).
  Passing an invalid fragment specification will croak and set error 2013.
  
  =head2 column_names
  
  Set the "keys" that will be used in the  L</getline_hr>  calls.  If no keys
  (column names) are passed, it will return the current setting as a list.
  
  L</column_names> accepts a list of scalars  (the column names)  or a single
  array_ref, so you can pass the return value from L</getline> too:
  
   $csv->column_names ($csv->getline ($fh));
  
  L</column_names> does B<no> checking on duplicates at all, which might lead
  to unexpected results.   Undefined entries will be replaced with the string
  C<"\cAUNDEF\cA">, so
  
   $csv->column_names (undef, "", "name", "name");
   $hr = $csv->getline_hr ($fh);
  
  will set C<< $hr->{"\cAUNDEF\cA"} >> to the 1st field,  C<< $hr->{""} >> to
  the 2nd field, and C<< $hr->{name} >> to the 4th field,  discarding the 3rd
  field.
  
  L</column_names> croaks on invalid arguments.
  
  =head2 header
  
  This method does NOT work in perl-5.6.x
  
  Parse the CSV header and set L<C<sep>|/sep>, column_names and encoding.
  
   my @hdr = $csv->header ($fh);
   $csv->header ($fh, { sep_set => [ ";", ",", "|", "\t" ] });
   $csv->header ($fh, { detect_bom => 1, munge_column_names => "lc" });
  
  The first argument should be a file handle.
  
  This method resets some object properties,  as it is supposed to be invoked
  only once per file or stream.  It will leave attributes C<column_names> and
  C<bound_columns> alone if setting column names is disabled. Reading headers
  on previously process objects might fail on perl-5.8.0 and older.
  
  Assuming that the file opened for parsing has a header, and the header does
  not contain problematic characters like embedded newlines,   read the first
  line from the open handle then auto-detect whether the header separates the
  column names with a character from the allowed separator list.
  
  If any of the allowed separators matches,  and none of the I<other> allowed
  separators match,  set  L<C<sep>|/sep>  to that  separator  for the current
  CSV instance and use it to parse the first line, map those to lowercase,
  and use that to set the instance L</column_names>:
  
   my $csv = Text::CSV->new ({ binary => 1, auto_diag => 1 });
   open my $fh, "<", "file.csv";
   binmode $fh; # for Windows
   $csv->header ($fh);
   while (my $row = $csv->getline_hr ($fh)) {
       ...
       }
  
  If the header is empty,  contains more than one unique separator out of the
  allowed set,  contains empty fields,   or contains identical fields  (after
  folding), it will croak with error 1010, 1011, 1012, or 1013 respectively.
  
  If the header contains embedded newlines or is not valid  CSV  in any other
  way, this method will croak and leave the parse error untouched.
  
  A successful call to C<header>  will always set the  L<C<sep>|/sep>  of the
  C<$csv> object. This behavior can not be disabled.
  
  =head3 return value
  
  On error this method will croak.
  
  In list context,  the headers will be returned whether they are used to set
  L</column_names> or not.
  
  In scalar context, the instance itself is returned.  B<Note>: the values as
  found in the header will effectively be  B<lost> if  C<set_column_names> is
  false.
  
  =head3 Options
  
  =over 2
  
  =item sep_set
  
   $csv->header ($fh, { sep_set => [ ";", ",", "|", "\t" ] });
  
  The list of legal separators defaults to C<[ ";", "," ]> and can be changed
  by this option.  As this is probably the most often used option,  it can be
  passed on its own as an unnamed argument:
  
   $csv->header ($fh, [ ";", ",", "|", "\t", "::", "\x{2063}" ]);
  
  Multi-byte  sequences are allowed,  both multi-character and  Unicode.  See
  L<C<sep>|/sep>.
  
  =item detect_bom
  
   $csv->header ($fh, { detect_bom => 1 });
  
  The default behavior is to detect if the header line starts with a BOM.  If
  the header has a BOM, use that to set the encoding of C<$fh>.  This default
  behavior can be disabled by passing a false value to C<detect_bom>.
  
  Supported encodings from BOM are: UTF-8, UTF-16BE, UTF-16LE, UTF-32BE,  and
  UTF-32LE. BOM also supports UTF-1, UTF-EBCDIC, SCSU, BOCU-1,  and GB-18030
  but L<Encode> does not (yet). UTF-7 is not supported.
  
  If a supported BOM was detected as start of the stream, it is stored in the
  object attribute C<ENCODING>.
  
   my $enc = $csv->{ENCODING};
  
  The encoding is used with C<binmode> on C<$fh>.
  
  If the handle was opened in a (correct) encoding,  this method will  B<not>
  alter the encoding, as it checks the leading B<bytes> of the first line. In
  case the stream starts with a decoded BOM (C<U+FEFF>), C<{ENCODING}> will be
  C<""> (empty) instead of the default C<undef>.
  
  =item munge_column_names
  
  This option offers the means to modify the column names into something that
  is most useful to the application.   The default is to map all column names
  to lower case.
  
   $csv->header ($fh, { munge_column_names => "lc" });
  
  The following values are available:
  
    lc     - lower case
    uc     - upper case
    db     - valid DB field names
    none   - do not change
    \%hash - supply a mapping
    \&cb   - supply a callback
  
  =over 2
  
  =item Lower case
  
   $csv->header ($fh, { munge_column_names => "lc" });
  
  The header is changed to all lower-case
  
   $_ = lc;
  
  =item Upper case
  
   $csv->header ($fh, { munge_column_names => "uc" });
  
  The header is changed to all upper-case
  
   $_ = uc;
  
  =item Literal
  
   $csv->header ($fh, { munge_column_names => "none" });
  
  =item Hash
  
   $csv->header ($fh, { munge_column_names => { foo => "sombrero" });
  
  if a value does not exist, the original value is used unchanged
  
  =item Database
  
   $csv->header ($fh, { munge_column_names => "db" });
  
  =over 2
  
  =item -
  
  lower-case
  
  =item -
  
  all sequences of non-word characters are replaced with an underscore
  
  =item -
  
  all leading underscores are removed
  
  =back
  
   $_ = lc (s/\W+/_/gr =~ s/^_+//r);
  
  =item Callback
  
   $csv->header ($fh, { munge_column_names => sub { fc } });
   $csv->header ($fh, { munge_column_names => sub { "column_".$col++ } });
   $csv->header ($fh, { munge_column_names => sub { lc (s/\W+/_/gr) } });
  
  As this callback is called in a C<map>, you can use C<$_> directly.
  
  =back
  
  =item set_column_names
  
   $csv->header ($fh, { set_column_names => 1 });
  
  The default is to set the instances column names using  L</column_names> if
  the method is successful,  so subsequent calls to L</getline_hr> can return
  a hash. Disable setting the header can be forced by using a false value for
  this option.
  
  As described in L</return value> above, content is lost in scalar context.
  
  =back
  
  =head3 Validation
  
  When receiving CSV files from external sources,  this method can be used to
  protect against changes in the layout by restricting to known headers  (and
  typos in the header fields).
  
   my %known = (
       "record key" => "c_rec",
       "rec id"     => "c_rec",
       "id_rec"     => "c_rec",
       "kode"       => "code",
       "code"       => "code",
       "vaule"      => "value",
       "value"      => "value",
       );
   my $csv = Text::CSV->new ({ binary => 1, auto_diag => 1 });
   open my $fh, "<", $source or die "$source: $!";
   $csv->header ($fh, { munge_column_names => sub {
       s/\s+$//;
       s/^\s+//;
       $known{lc $_} or die "Unknown column '$_' in $source";
       }});
   while (my $row = $csv->getline_hr ($fh)) {
       say join "\t", $row->{c_rec}, $row->{code}, $row->{value};
       }
  
  =head2 bind_columns
  
  Takes a list of scalar references to be used for output with  L</print>  or
  to store in the fields fetched by L</getline>.  When you do not pass enough
  references to store the fetched fields in, L</getline> will fail with error
  C<3006>.  If you pass more than there are fields to return,  the content of
  the remaining references is left untouched.
  
   $csv->bind_columns (\$code, \$name, \$price, \$description);
   while ($csv->getline ($fh)) {
       print "The price of a $name is \x{20ac} $price\n";
       }
  
  To reset or clear all column binding, call L</bind_columns> with the single
  argument C<undef>. This will also clear column names.
  
   $csv->bind_columns (undef);
  
  If no arguments are passed at all, L</bind_columns> will return the list of
  current bindings or C<undef> if no binds are active.
  
  Note that in parsing with  C<bind_columns>,  the fields are set on the fly.
  That implies that if the third field of a row causes an error  (or this row
  has just two fields where the previous row had more),  the first two fields
  already have been assigned the values of the current row, while the rest of
  the fields will still hold the values of the previous row.  If you want the
  parser to fail in these cases, use the L<C<strict>|/strict> attribute.
  
  =head2 eof
  
   $eof = $csv->eof ();
  
  If L</parse> or  L</getline>  was used with an IO stream,  this method will
  return true (1) if the last call hit end of file,  otherwise it will return
  false ('').  This is useful to see the difference between a failure and end
  of file.
  
  Note that if the parsing of the last line caused an error,  C<eof> is still
  true.  That means that if you are I<not> using L</auto_diag>, an idiom like
  
   while (my $row = $csv->getline ($fh)) {
       # ...
       }
   $csv->eof or $csv->error_diag;
  
  will I<not> report the error. You would have to change that to
  
   while (my $row = $csv->getline ($fh)) {
       # ...
       }
   +$csv->error_diag and $csv->error_diag;
  
  =head2 types
  
   $csv->types (\@tref);
  
  This method is used to force that  (all)  columns are of a given type.  For
  example, if you have an integer column,  two  columns  with  doubles  and a
  string column, then you might do a
  
   $csv->types ([Text::CSV::IV (),
                 Text::CSV::NV (),
                 Text::CSV::NV (),
                 Text::CSV::PV ()]);
  
  Column types are used only for I<decoding> columns while parsing,  in other
  words by the L</parse> and L</getline> methods.
  
  You can unset column types by doing a
  
   $csv->types (undef);
  
  or fetch the current type settings with
  
   $types = $csv->types ();
  
  =over 4
  
  =item IV
  
  =item CSV_TYPE_IV
  
  Set field type to integer.
  
  =item NV
  
  =item CSV_TYPE_NV
  
  Set field type to numeric/float.
  
  =item PV
  
  =item CSV_TYPE_PV
  
  Set field type to string.
  
  =back
  
  =head2 fields
  
   @columns = $csv->fields ();
  
  This method returns the input to   L</combine>  or the resultant decomposed
  fields of a successful L</parse>, whichever was called more recently.
  
  Note that the return value is undefined after using L</getline>, which does
  not fill the data structures returned by L</parse>.
  
  =head2 meta_info
  
   @flags = $csv->meta_info ();
  
  This method returns the "flags" of the input to L</combine> or the flags of
  the resultant  decomposed fields of  L</parse>,   whichever was called more
  recently.
  
  For each field,  a meta_info field will hold  flags that  inform  something
  about  the  field  returned  by  the  L</fields>  method or  passed to  the
  L</combine> method. The flags are bit-wise-C<or>'d like:
  
  =over 2
  
  =item C<0x0001>
  
  =item C<CSV_FLAGS_IS_QUOTED>
  
  The field was quoted.
  
  =item C<0x0002>
  
  =item C<CSV_FLAGS_IS_BINARY>
  
  The field was binary.
  
  =item C<0x0004>
  
  =item C<CSV_FLAGS_ERROR_IN_FIELD>
  
  The field was invalid.
  
  Currently only used when C<allow_loose_quotes> is active.
  
  =item C<0x0010>
  
  =item C<CSV_FLAGS_IS_MISSING>
  
  The field was missing.
  
  =back
  
  See the C<is_***> methods below.
  
  =head2 is_quoted
  
   my $quoted = $csv->is_quoted ($column_idx);
  
  where  C<$column_idx> is the  (zero-based)  index of the column in the last
  result of L</parse>.
  
  This returns a true value  if the data in the indicated column was enclosed
  in L<C<quote_char>|/quote_char> quotes.  This might be important for fields
  where content C<,20070108,> is to be treated as a numeric value,  and where
  C<,"20070108",> is explicitly marked as character string data.
  
  This method is only valid when L</keep_meta_info> is set to a true value.
  
  =head2 is_binary
  
   my $binary = $csv->is_binary ($column_idx);
  
  where  C<$column_idx> is the  (zero-based)  index of the column in the last
  result of L</parse>.
  
  This returns a true value if the data in the indicated column contained any
  byte in the range C<[\x00-\x08,\x10-\x1F,\x7F-\xFF]>.
  
  This method is only valid when L</keep_meta_info> is set to a true value.
  
  =head2 is_missing
  
   my $missing = $csv->is_missing ($column_idx);
  
  where  C<$column_idx> is the  (zero-based)  index of the column in the last
  result of L</getline_hr>.
  
   $csv->keep_meta_info (1);
   while (my $hr = $csv->getline_hr ($fh)) {
       $csv->is_missing (0) and next; # This was an empty line
       }
  
  When using  L</getline_hr>,  it is impossible to tell if the  parsed fields
  are C<undef> because they where not filled in the C<CSV> stream  or because
  they were not read at all, as B<all> the fields defined by L</column_names>
  are set in the hash-ref.    If you still need to know if all fields in each
  row are provided, you should enable L<C<keep_meta_info>|/keep_meta_info> so
  you can check the flags.
  
  If  L<C<keep_meta_info>|/keep_meta_info>  is C<false>,  C<is_missing>  will
  always return C<undef>, regardless of C<$column_idx> being valid or not. If
  this attribute is C<true> it will return either C<0> (the field is present)
  or C<1> (the field is missing).
  
  A special case is the empty line.  If the line is completely empty -  after
  dealing with the flags - this is still a valid CSV line:  it is a record of
  just one single empty field. However, if C<keep_meta_info> is set, invoking
  C<is_missing> with index C<0> will now return true.
  
  =head2 status
  
   $status = $csv->status ();
  
  This method returns the status of the last invoked L</combine> or L</parse>
  call. Status is success (true: C<1>) or failure (false: C<undef> or C<0>).
  
  Note that as this only keeps track of the status of above mentioned methods,
  you are probably looking for L<C<error_diag>|/error_diag> instead.
  
  =head2 error_input
  
   $bad_argument = $csv->error_input ();
  
  This method returns the erroneous argument (if it exists) of L</combine> or
  L</parse>,  whichever was called more recently.  If the last invocation was
  successful, C<error_input> will return C<undef>.
  
  Depending on the type of error, it I<might> also hold the data for the last
  error-input of L</getline>.
  
  =head2 error_diag
  
   Text::CSV->error_diag ();
   $csv->error_diag ();
   $error_code               = 0  + $csv->error_diag ();
   $error_str                = "" . $csv->error_diag ();
   ($cde, $str, $pos, $rec, $fld) = $csv->error_diag ();
  
  If (and only if) an error occurred,  this function returns  the diagnostics
  of that error.
  
  If called in void context,  this will print the internal error code and the
  associated error message to STDERR.
  
  If called in list context,  this will return  the error code  and the error
  message in that order.  If the last error was from parsing, the rest of the
  values returned are a best guess at the location  within the line  that was
  being parsed. Their values are 1-based.  The position currently is index of
  the byte at which the parsing failed in the current record. It might change
  to be the index of the current character in a later release. The records is
  the index of the record parsed by the csv instance. The field number is the
  index of the field the parser thinks it is currently  trying to  parse. See
  F<examples/csv-check> for how this can be used.
  
  If called in  scalar context,  it will return  the diagnostics  in a single
  scalar, a-la C<$!>.  It will contain the error code in numeric context, and
  the diagnostics message in string context.
  
  When called as a class method or a  direct function call,  the  diagnostics
  are that of the last L</new> call.
  
  =head2 record_number
  
   $recno = $csv->record_number ();
  
  Returns the records parsed by this csv instance.  This value should be more
  accurate than C<$.> when embedded newlines come in play. Records written by
  this instance are not counted.
  
  =head2 SetDiag
  
   $csv->SetDiag (0);
  
  Use to reset the diagnostics if you are dealing with errors.
  
  =head1 ADDITIONAL METHODS
  
  =over
  
  =item backend
  
  Returns the backend module name called by Text::CSV.
  C<module> is an alias.
  
  =item is_xs
  
  Returns true value if Text::CSV uses an XS backend.
  
  =item is_pp
  
  Returns true value if Text::CSV uses a pure-Perl backend.
  
  =back
  
  =head1 FUNCTIONS
  
  This section is also taken from Text::CSV_XS.
  
  =head2 csv
  
  This function is not exported by default and should be explicitly requested:
  
   use Text::CSV qw( csv );
  
  This is a high-level function that aims at simple (user) interfaces.  This
  can be used to read/parse a C<CSV> file or stream (the default behavior) or
  to produce a file or write to a stream (define the  C<out>  attribute).  It
  returns an array- or hash-reference on parsing (or C<undef> on fail) or the
  numeric value of  L</error_diag>  on writing.  When this function fails you
  can get to the error using the class call to L</error_diag>
  
   my $aoa = csv (in => "test.csv") or
       die Text::CSV->error_diag;
  
  This function takes the arguments as key-value pairs. This can be passed as
  a list or as an anonymous hash:
  
   my $aoa = csv (  in => "test.csv", sep_char => ";");
   my $aoh = csv ({ in => $fh, headers => "auto" });
  
  The arguments passed consist of two parts:  the arguments to L</csv> itself
  and the optional attributes to the  C<CSV>  object used inside the function
  as enumerated and explained in L</new>.
  
  If not overridden, the default option used for CSV is
  
   auto_diag   => 1
   escape_null => 0
  
  The option that is always set and cannot be altered is
  
   binary      => 1
  
  As this function will likely be used in one-liners,  it allows  C<quote> to
  be abbreviated as C<quo>,  and  C<escape_char> to be abbreviated as  C<esc>
  or C<escape>.
  
  Alternative invocations:
  
   my $aoa = Text::CSV::csv (in => "file.csv");
  
   my $csv = Text::CSV->new ();
   my $aoa = $csv->csv (in => "file.csv");
  
  In the latter case, the object attributes are used from the existing object
  and the attribute arguments in the function call are ignored:
  
   my $csv = Text::CSV->new ({ sep_char => ";" });
   my $aoh = $csv->csv (in => "file.csv", bom => 1);
  
  will parse using C<;> as C<sep_char>, not C<,>.
  
  =head3 in
  
  Used to specify the source.  C<in> can be a file name (e.g. C<"file.csv">),
  which will be  opened for reading  and closed when finished,  a file handle
  (e.g.  C<$fh> or C<FH>),  a reference to a glob (e.g. C<\*ARGV>),  the glob
  itself (e.g. C<*STDIN>), or a reference to a scalar (e.g. C<\q{1,2,"csv"}>).
  
  When used with L</out>, C<in> should be a reference to a CSV structure (AoA
  or AoH)  or a CODE-ref that returns an array-reference or a hash-reference.
  The code-ref will be invoked with no arguments.
  
   my $aoa = csv (in => "file.csv");
  
   open my $fh, "<", "file.csv";
   my $aoa = csv (in => $fh);
  
   my $csv = [ [qw( Foo Bar )], [ 1, 2 ], [ 2, 3 ]];
   my $err = csv (in => $csv, out => "file.csv");
  
  If called in void context without the L</out> attribute, the resulting ref
  will be used as input to a subsequent call to csv:
  
   csv (in => "file.csv", filter => { 2 => sub { length > 2 }})
  
  will be a shortcut to
  
   csv (in => csv (in => "file.csv", filter => { 2 => sub { length > 2 }}))
  
  where, in the absence of the C<out> attribute, this is a shortcut to
  
   csv (in  => csv (in => "file.csv", filter => { 2 => sub { length > 2 }}),
        out => *STDOUT)
  
  =head3 out
  
   csv (in => $aoa, out => "file.csv");
   csv (in => $aoa, out => $fh);
   csv (in => $aoa, out =>   STDOUT);
   csv (in => $aoa, out =>  *STDOUT);
   csv (in => $aoa, out => \*STDOUT);
   csv (in => $aoa, out => \my $data);
   csv (in => $aoa, out =>  undef);
   csv (in => $aoa, out => \"skip");
  
   csv (in => $fh,  out => \@aoa);
   csv (in => $fh,  out => \@aoh, bom => 1);
   csv (in => $fh,  out => \%hsh, key => "key");
  
  In output mode, the default CSV options when producing CSV are
  
   eol       => "\r\n"
  
  The L</fragment> attribute is ignored in output mode.
  
  C<out> can be a file name  (e.g.  C<"file.csv">),  which will be opened for
  writing and closed when finished,  a file handle (e.g. C<$fh> or C<FH>),  a
  reference to a glob (e.g. C<\*STDOUT>),  the glob itself (e.g. C<*STDOUT>),
  or a reference to a scalar (e.g. C<\my $data>).
  
   csv (in => sub { $sth->fetch },            out => "dump.csv");
   csv (in => sub { $sth->fetchrow_hashref }, out => "dump.csv",
        headers => $sth->{NAME_lc});
  
  When a code-ref is used for C<in>, the output is generated  per invocation,
  so no buffering is involved. This implies that there is no size restriction
  on the number of records. The C<csv> function ends when the coderef returns
  a false value.
  
  If C<out> is set to a reference of the literal string C<"skip">, the output
  will be suppressed completely,  which might be useful in combination with a
  filter for side effects only.
  
   my %cache;
   csv (in    => "dump.csv",
        out   => \"skip",
        on_in => sub { $cache{$_[1][1]}++ });
  
  Currently,  setting C<out> to any false value  (C<undef>, C<"">, 0) will be
  equivalent to C<\"skip">.
  
  If the C<in> argument point to something to parse, and the C<out> is set to
  a reference to an C<ARRAY> or a C<HASH>, the output is appended to the data
  in the existing reference. The result of the parse should match what exists
  in the reference passed. This might come handy when you have to parse a set
  of files with similar content (like data stored per period) and you want to
  collect that into a single data structure:
  
   my %hash;
   csv (in => $_, out => \%hash, key => "id") for sort glob "foo-[0-9]*.csv";
  
   my @list; # List of arrays
   csv (in => $_, out => \@list)              for sort glob "foo-[0-9]*.csv";
  
   my @list; # List of hashes
   csv (in => $_, out => \@list, bom => 1)    for sort glob "foo-[0-9]*.csv";
  
  =head3 encoding
  
  If passed,  it should be an encoding accepted by the  C<:encoding()> option
  to C<open>. There is no default value. This attribute does not work in perl
  5.6.x.  C<encoding> can be abbreviated to C<enc> for ease of use in command
  line invocations.
  
  If C<encoding> is set to the literal value C<"auto">, the method L</header>
  will be invoked on the opened stream to check if there is a BOM and set the
  encoding accordingly.   This is equal to passing a true value in the option
  L<C<detect_bom>|/detect_bom>.
  
  Encodings can be stacked, as supported by C<binmode>:
  
   # Using PerlIO::via::gzip
   csv (in       => \@csv,
        out      => "test.csv:via.gz",
        encoding => ":via(gzip):encoding(utf-8)",
        );
   $aoa = csv (in => "test.csv:via.gz",  encoding => ":via(gzip)");
  
   # Using PerlIO::gzip
   csv (in       => \@csv,
        out      => "test.csv:via.gz",
        encoding => ":gzip:encoding(utf-8)",
        );
   $aoa = csv (in => "test.csv:gzip.gz", encoding => ":gzip");
  
  =head3 detect_bom
  
  If  C<detect_bom>  is given, the method  L</header>  will be invoked on the
  opened stream to check if there is a BOM and set the encoding accordingly.
  
  C<detect_bom> can be abbreviated to C<bom>.
  
  This is the same as setting L<C<encoding>|/encoding> to C<"auto">.
  
  Note that as the method  L</header> is invoked,  its default is to also set
  the headers.
  
  =head3 headers
  
  If this attribute is not given, the default behavior is to produce an array
  of arrays.
  
  If C<headers> is supplied,  it should be an anonymous list of column names,
  an anonymous hashref, a coderef, or a literal flag:  C<auto>, C<lc>, C<uc>,
  or C<skip>.
  
  =over 2
  
  =item skip
  
  When C<skip> is used, the header will not be included in the output.
  
   my $aoa = csv (in => $fh, headers => "skip");
  
  C<skip> is invalid/ignored in combinations with L<C<detect_bom>|/detect_bom>.
  
  =item auto
  
  If C<auto> is used, the first line of the C<CSV> source will be read as the
  list of field headers and used to produce an array of hashes.
  
   my $aoh = csv (in => $fh, headers => "auto");
  
  =item lc
  
  If C<lc> is used,  the first line of the  C<CSV> source will be read as the
  list of field headers mapped to  lower case and used to produce an array of
  hashes. This is a variation of C<auto>.
  
   my $aoh = csv (in => $fh, headers => "lc");
  
  =item uc
  
  If C<uc> is used,  the first line of the  C<CSV> source will be read as the
  list of field headers mapped to  upper case and used to produce an array of
  hashes. This is a variation of C<auto>.
  
   my $aoh = csv (in => $fh, headers => "uc");
  
  =item CODE
  
  If a coderef is used,  the first line of the  C<CSV> source will be read as
  the list of mangled field headers in which each field is passed as the only
  argument to the coderef. This list is used to produce an array of hashes.
  
   my $aoh = csv (in      => $fh,
                  headers => sub { lc ($_[0]) =~ s/kode/code/gr });
  
  this example is a variation of using C<lc> where all occurrences of C<kode>
  are replaced with C<code>.
  
  =item ARRAY
  
  If  C<headers>  is an anonymous list,  the entries in the list will be used
  as field names. The first line is considered data instead of headers.
  
   my $aoh = csv (in => $fh, headers => [qw( Foo Bar )]);
   csv (in => $aoa, out => $fh, headers => [qw( code description price )]);
  
  =item HASH
  
  If C<headers> is a hash reference, this implies C<auto>, but header fields
  that exist as key in the hashref will be replaced by the value for that
  key. Given a CSV file like
  
   post-kode,city,name,id number,fubble
   1234AA,Duckstad,Donald,13,"X313DF"
  
  using
  
   csv (headers => { "post-kode" => "pc", "id number" => "ID" }, ...
  
  will return an entry like
  
   { pc     => "1234AA",
     city   => "Duckstad",
     name   => "Donald",
     ID     => "13",
     fubble => "X313DF",
     }
  
  =back
  
  See also L<C<munge_column_names>|/munge_column_names> and
  L<C<set_column_names>|/set_column_names>.
  
  =head3 munge_column_names
  
  If C<munge_column_names> is set,  the method  L</header>  is invoked on the
  opened stream with all matching arguments to detect and set the headers.
  
  C<munge_column_names> can be abbreviated to C<munge>.
  
  =head3 key
  
  If passed,  will default  L<C<headers>|/headers>  to C<"auto"> and return a
  hashref instead of an array of hashes. Allowed values are simple scalars or
  array-references where the first element is the joiner and the rest are the
  fields to join to combine the key.
  
   my $ref = csv (in => "test.csv", key => "code");
   my $ref = csv (in => "test.csv", key => [ ":" => "code", "color" ]);
  
  with test.csv like
  
   code,product,price,color
   1,pc,850,gray
   2,keyboard,12,white
   3,mouse,5,black
  
  the first example will return
  
    { 1   => {
          code    => 1,
          color   => 'gray',
          price   => 850,
          product => 'pc'
          },
      2   => {
          code    => 2,
          color   => 'white',
          price   => 12,
          product => 'keyboard'
          },
      3   => {
          code    => 3,
          color   => 'black',
          price   => 5,
          product => 'mouse'
          }
      }
  
  the second example will return
  
    { "1:gray"    => {
          code    => 1,
          color   => 'gray',
          price   => 850,
          product => 'pc'
          },
      "2:white"   => {
          code    => 2,
          color   => 'white',
          price   => 12,
          product => 'keyboard'
          },
      "3:black"   => {
          code    => 3,
          color   => 'black',
          price   => 5,
          product => 'mouse'
          }
      }
  
  The C<key> attribute can be combined with L<C<headers>|/headers> for C<CSV>
  date that has no header line, like
  
   my $ref = csv (
       in      => "foo.csv",
       headers => [qw( c_foo foo bar description stock )],
       key     =>     "c_foo",
       );
  
  =head3 value
  
  Used to create key-value hashes.
  
  Only allowed when C<key> is valid. A C<value> can be either a single column
  label or an anonymous list of column labels.  In the first case,  the value
  will be a simple scalar value, in the latter case, it will be a hashref.
  
   my $ref = csv (in => "test.csv", key   => "code",
                                    value => "price");
   my $ref = csv (in => "test.csv", key   => "code",
                                    value => [ "product", "price" ]);
   my $ref = csv (in => "test.csv", key   => [ ":" => "code", "color" ],
                                    value => "price");
   my $ref = csv (in => "test.csv", key   => [ ":" => "code", "color" ],
                                    value => [ "product", "price" ]);
  
  with test.csv like
  
   code,product,price,color
   1,pc,850,gray
   2,keyboard,12,white
   3,mouse,5,black
  
  the first example will return
  
    { 1 => 850,
      2 =>  12,
      3 =>   5,
      }
  
  the second example will return
  
    { 1   => {
          price   => 850,
          product => 'pc'
          },
      2   => {
          price   => 12,
          product => 'keyboard'
          },
      3   => {
          price   => 5,
          product => 'mouse'
          }
      }
  
  the third example will return
  
    { "1:gray"    => 850,
      "2:white"   =>  12,
      "3:black"   =>   5,
      }
  
  the fourth example will return
  
    { "1:gray"    => {
          price   => 850,
          product => 'pc'
          },
      "2:white"   => {
          price   => 12,
          product => 'keyboard'
          },
      "3:black"   => {
          price   => 5,
          product => 'mouse'
          }
      }
  
  =head3 keep_headers
  
  When using hashes,  keep the column names into the arrayref passed,  so all
  headers are available after the call in the original order.
  
   my $aoh = csv (in => "file.csv", keep_headers => \my @hdr);
  
  This attribute can be abbreviated to C<kh> or passed as C<keep_column_names>.
  
  This attribute implies a default of C<auto> for the C<headers> attribute.
  
  The headers can also be kept internally to keep stable header order:
  
   csv (in      => csv (in => "file.csv", kh => "internal"),
        out     => "new.csv",
        kh      => "internal");
  
  where C<internal> can also be C<1>, C<yes>, or C<true>. This is similar to
  
   my @h;
   csv (in      => csv (in => "file.csv", kh => \@h),
        out     => "new.csv",
        headers => \@h);
  
  =head3 fragment
  
  Only output the fragment as defined in the L</fragment> method. This option
  is ignored when I<generating> C<CSV>. See L</out>.
  
  Combining all of them could give something like
  
   use Text::CSV qw( csv );
   my $aoh = csv (
       in       => "test.txt",
       encoding => "utf-8",
       headers  => "auto",
       sep_char => "|",
       fragment => "row=3;6-9;15-*",
       );
   say $aoh->[15]{Foo};
  
  =head3 sep_set
  
  If C<sep_set> is set, the method L</header> is invoked on the opened stream
  to detect and set L<C<sep_char>|/sep_char> with the given set.
  
  C<sep_set> can be abbreviated to C<seps>. If neither C<sep_set> not C<seps>
  is given, but C<sep> is defined, C<sep_set> defaults to C<[ sep ]>. This is
  only supported for perl version 5.10 and up.
  
  Note that as the  L</header> method is invoked,  its default is to also set
  the headers.
  
  =head3 set_column_names
  
  If  C<set_column_names> is passed,  the method L</header> is invoked on the
  opened stream with all arguments meant for L</header>.
  
  If C<set_column_names> is passed as a false value, the content of the first
  row is only preserved if the output is AoA:
  
  With an input-file like
  
   bAr,foo
   1,2
   3,4,5
  
  This call
  
   my $aoa = csv (in => $file, set_column_names => 0);
  
  will result in
  
   [[ "bar", "foo"     ],
    [ "1",   "2"       ],
    [ "3",   "4",  "5" ]]
  
  and
  
   my $aoa = csv (in => $file, set_column_names => 0, munge => "none");
  
  will result in
  
   [[ "bAr", "foo"     ],
    [ "1",   "2"       ],
    [ "3",   "4",  "5" ]]
  
  =head2 Callbacks
  
  Callbacks enable actions triggered from the I<inside> of Text::CSV.
  
  While most of what this enables  can easily be done in an  unrolled loop as
  described in the L</SYNOPSIS> callbacks can be used to meet special demands
  or enhance the L</csv> function.
  
  =over 2
  
  =item error
  
   $csv->callbacks (error => sub { $csv->SetDiag (0) });
  
  the C<error>  callback is invoked when an error occurs,  but  I<only>  when
  L</auto_diag> is set to a true value. A callback is invoked with the values
  returned by L</error_diag>:
  
   my ($c, $s);
  
   sub ignore3006 {
       my ($err, $msg, $pos, $recno, $fldno) = @_;
       if ($err == 3006) {
           # ignore this error
           ($c, $s) = (undef, undef);
           Text::CSV->SetDiag (0);
           }
       # Any other error
       return;
       } # ignore3006
  
   $csv->callbacks (error => \&ignore3006);
   $csv->bind_columns (\$c, \$s);
   while ($csv->getline ($fh)) {
       # Error 3006 will not stop the loop
       }
  
  =item after_parse
  
   $csv->callbacks (after_parse => sub { push @{$_[1]}, "NEW" });
   while (my $row = $csv->getline ($fh)) {
       $row->[-1] eq "NEW";
       }
  
  This callback is invoked after parsing with  L</getline>  only if no  error
  occurred.  The callback is invoked with two arguments:   the current C<CSV>
  parser object and an array reference to the fields parsed.
  
  The return code of the callback is ignored  unless it is a reference to the
  string "skip", in which case the record will be skipped in L</getline_all>.
  
   sub add_from_db {
       my ($csv, $row) = @_;
       $sth->execute ($row->[4]);
       push @$row, $sth->fetchrow_array;
       } # add_from_db
  
   my $aoa = csv (in => "file.csv", callbacks => {
       after_parse => \&add_from_db });
  
  This hook can be used for validation:
  
  =over 2
  
  =item FAIL
  
  Die if any of the records does not validate a rule:
  
   after_parse => sub {
       $_[1][4] =~ m/^[0-9]{4}\s?[A-Z]{2}$/ or
           die "5th field does not have a valid Dutch zipcode";
       }
  
  =item DEFAULT
  
  Replace invalid fields with a default value:
  
   after_parse => sub { $_[1][2] =~ m/^\d+$/ or $_[1][2] = 0 }
  
  =item SKIP
  
  Skip records that have invalid fields (only applies to L</getline_all>):
  
   after_parse => sub { $_[1][0] =~ m/^\d+$/ or return \"skip"; }
  
  =back
  
  =item before_print
  
   my $idx = 1;
   $csv->callbacks (before_print => sub { $_[1][0] = $idx++ });
   $csv->print (*STDOUT, [ 0, $_ ]) for @members;
  
  This callback is invoked  before printing with  L</print>  only if no error
  occurred.  The callback is invoked with two arguments:  the current  C<CSV>
  parser object and an array reference to the fields passed.
  
  The return code of the callback is ignored.
  
   sub max_4_fields {
       my ($csv, $row) = @_;
       @$row > 4 and splice @$row, 4;
       } # max_4_fields
  
   csv (in => csv (in => "file.csv"), out => *STDOUT,
       callbacks => { before_print => \&max_4_fields });
  
  This callback is not active for L</combine>.
  
  =back
  
  =head3 Callbacks for csv ()
  
  The L</csv> allows for some callbacks that do not integrate in XS internals
  but only feature the L</csv> function.
  
    csv (in        => "file.csv",
         callbacks => {
             filter       => { 6 => sub { $_ > 15 } },    # first
             after_parse  => sub { say "AFTER PARSE";  }, # first
             after_in     => sub { say "AFTER IN";     }, # second
             on_in        => sub { say "ON IN";        }, # third
             },
         );
  
    csv (in        => $aoh,
         out       => "file.csv",
         callbacks => {
             on_in        => sub { say "ON IN";        }, # first
             before_out   => sub { say "BEFORE OUT";   }, # second
             before_print => sub { say "BEFORE PRINT"; }, # third
             },
         );
  
  =over 2
  
  =item filter
  
  This callback can be used to filter records.  It is called just after a new
  record has been scanned.  The callback accepts a:
  
  =over 2
  
  =item hashref
  
  The keys are the index to the row (the field name or field number, 1-based)
  and the values are subs to return a true or false value.
  
   csv (in => "file.csv", filter => {
              3 => sub { m/a/ },       # third field should contain an "a"
              5 => sub { length > 4 }, # length of the 5th field minimal 5
              });
  
   csv (in => "file.csv", filter => { foo => sub { $_ > 4 }});
  
  If the keys to the filter hash contain any character that is not a digit it
  will also implicitly set L</headers> to C<"auto">  unless  L</headers>  was
  already passed as argument.  When headers are active, returning an array of
  hashes, the filter is not applicable to the header itself.
  
  All sub results should match, as in AND.
  
  The context of the callback sets  C<$_> localized to the field indicated by
  the filter. The two arguments are as with all other callbacks, so the other
  fields in the current row can be seen:
  
   filter => { 3 => sub { $_ > 100 ? $_[1][1] =~ m/A/ : $_[1][6] =~ m/B/ }}
  
  If the context is set to return a list of hashes  (L</headers> is defined),
  the current record will also be available in the localized C<%_>:
  
   filter => { 3 => sub { $_ > 100 && $_{foo} =~ m/A/ && $_{bar} < 1000  }}
  
  If the filter is used to I<alter> the content by changing C<$_>,  make sure
  that the sub returns true in order not to have that record skipped:
  
   filter => { 2 => sub { $_ = uc }}
  
  will upper-case the second field, and then skip it if the resulting content
  evaluates to false. To always accept, end with truth:
  
   filter => { 2 => sub { $_ = uc; 1 }}
  
  =item coderef
  
   csv (in => "file.csv", filter => sub { $n++; 0; });
  
  If the argument to C<filter> is a coderef,  it is an alias or shortcut to a
  filter on column 0:
  
   csv (filter => sub { $n++; 0 });
  
  is equal to
  
   csv (filter => { 0 => sub { $n++; 0 });
  
  =item filter-name
  
   csv (in => "file.csv", filter => "not_blank");
   csv (in => "file.csv", filter => "not_empty");
   csv (in => "file.csv", filter => "filled");
  
  These are predefined filters
  
  Given a file like (line numbers prefixed for doc purpose only):
  
   1:1,2,3
   2:
   3:,
   4:""
   5:,,
   6:, ,
   7:"",
   8:" "
   9:4,5,6
  
  =over 2
  
  =item not_blank
  
  Filter out the blank lines
  
  This filter is a shortcut for
  
   filter => { 0 => sub { @{$_[1]} > 1 or
               defined $_[1][0] && $_[1][0] ne "" } }
  
  Due to the implementation,  it is currently impossible to also filter lines
  that consists only of a quoted empty field. These lines are also considered
  blank lines.
  
  With the given example, lines 2 and 4 will be skipped.
  
  =item not_empty
  
  Filter out lines where all the fields are empty.
  
  This filter is a shortcut for
  
   filter => { 0 => sub { grep { defined && $_ ne "" } @{$_[1]} } }
  
  A space is not regarded being empty, so given the example data, lines 2, 3,
  4, 5, and 7 are skipped.
  
  =item filled
  
  Filter out lines that have no visible data
  
  This filter is a shortcut for
  
   filter => { 0 => sub { grep { defined && m/\S/ } @{$_[1]} } }
  
  This filter rejects all lines that I<not> have at least one field that does
  not evaluate to the empty string.
  
  With the given example data, this filter would skip lines 2 through 8.
  
  =back
  
  =back
  
  One could also use modules like L<Types::Standard>:
  
   use Types::Standard -types;
  
   my $type   = Tuple[Str, Str, Int, Bool, Optional[Num]];
   my $check  = $type->compiled_check;
  
   # filter with compiled check and warnings
   my $aoa = csv (
      in     => \$data,
      filter => {
          0 => sub {
              my $ok = $check->($_[1]) or
                  warn $type->get_message ($_[1]), "\n";
              return $ok;
              },
          },
      );
  
  =item after_in
  
  This callback is invoked for each record after all records have been parsed
  but before returning the reference to the caller.  The hook is invoked with
  two arguments:  the current  C<CSV>  parser object  and a  reference to the
  record.   The reference can be a reference to a  HASH  or a reference to an
  ARRAY as determined by the arguments.
  
  This callback can also be passed as  an attribute without the  C<callbacks>
  wrapper.
  
  =item before_out
  
  This callback is invoked for each record before the record is printed.  The
  hook is invoked with two arguments:  the current C<CSV> parser object and a
  reference to the record.   The reference can be a reference to a  HASH or a
  reference to an ARRAY as determined by the arguments.
  
  This callback can also be passed as an attribute  without the  C<callbacks>
  wrapper.
  
  This callback makes the row available in C<%_> if the row is a hashref.  In
  this case C<%_> is writable and will change the original row.
  
  =item on_in
  
  This callback acts exactly as the L</after_in> or the L</before_out> hooks.
  
  This callback can also be passed as an attribute  without the  C<callbacks>
  wrapper.
  
  This callback makes the row available in C<%_> if the row is a hashref.  In
  this case C<%_> is writable and will change the original row. So e.g. with
  
    my $aoh = csv (
        in      => \"foo\n1\n2\n",
        headers => "auto",
        on_in   => sub { $_{bar} = 2; },
        );
  
  C<$aoh> will be:
  
    [ { foo => 1,
        bar => 2,
        }
      { foo => 2,
        bar => 2,
        }
      ]
  
  =item csv
  
  The I<function>  L</csv> can also be called as a method or with an existing
  Text::CSV object. This could help if the function is to be invoked a lot
  of times and the overhead of creating the object internally over  and  over
  again would be prevented by passing an existing instance.
  
   my $csv = Text::CSV->new ({ binary => 1, auto_diag => 1 });
  
   my $aoa = $csv->csv (in => $fh);
   my $aoa = csv (in => $fh, csv => $csv);
  
  both act the same. Running this 20000 times on a 20 lines CSV file,  showed
  a 53% speedup.
  
  =back
  
  =head1 DIAGNOSTICS
  
  This section is also taken from Text::CSV_XS.
  
  Still under construction ...
  
  If an error occurs,  C<< $csv->error_diag >> can be used to get information
  on the cause of the failure. Note that for speed reasons the internal value
  is never cleared on success,  so using the value returned by L</error_diag>
  in normal cases - when no error occurred - may cause unexpected results.
  
  If the constructor failed, the cause can be found using L</error_diag> as a
  class method, like C<< Text::CSV->error_diag >>.
  
  The C<< $csv->error_diag >> method is automatically invoked upon error when
  the contractor was called with  L<C<auto_diag>|/auto_diag>  set to  C<1> or
  C<2>, or when L<autodie> is in effect.  When set to C<1>, this will cause a
  C<warn> with the error message,  when set to C<2>, it will C<die>. C<2012 -
  EOF> is excluded from L<C<auto_diag>|/auto_diag> reports.
  
  Errors can be (individually) caught using the L</error> callback.
  
  The errors as described below are available. I have tried to make the error
  itself explanatory enough, but more descriptions will be added. For most of
  these errors, the first three capitals describe the error category:
  
  =over 2
  
  =item *
  INI
  
  Initialization error or option conflict.
  
  =item *
  ECR
  
  Carriage-Return related parse error.
  
  =item *
  EOF
  
  End-Of-File related parse error.
  
  =item *
  EIQ
  
  Parse error inside quotation.
  
  =item *
  EIF
  
  Parse error inside field.
  
  =item *
  ECB
  
  Combine error.
  
  =item *
  EHR
  
  HashRef parse related error.
  
  =back
  
  And below should be the complete list of error codes that can be returned:
  
  =over 2
  
  =item *
  1001 "INI - sep_char is equal to quote_char or escape_char"
  
  The  L<separation character|/sep_char>  cannot be equal to  L<the quotation
  character|/quote_char> or to L<the escape character|/escape_char>,  as this
  would invalidate all parsing rules.
  
  =item *
  1002 "INI - allow_whitespace with escape_char or quote_char SP or TAB"
  
  Using the  L<C<allow_whitespace>|/allow_whitespace>  attribute  when either
  L<C<quote_char>|/quote_char> or L<C<escape_char>|/escape_char>  is equal to
  C<SPACE> or C<TAB> is too ambiguous to allow.
  
  =item *
  1003 "INI - \r or \n in main attr not allowed"
  
  Using default L<C<eol>|/eol> characters in either L<C<sep_char>|/sep_char>,
  L<C<quote_char>|/quote_char>,   or  L<C<escape_char>|/escape_char>  is  not
  allowed.
  
  =item *
  1004 "INI - callbacks should be undef or a hashref"
  
  The L<C<callbacks>|/Callbacks>  attribute only allows one to be C<undef> or
  a hash reference.
  
  =item *
  1005 "INI - EOL too long"
  
  The value passed for EOL is exceeding its maximum length (16).
  
  =item *
  1006 "INI - SEP too long"
  
  The value passed for SEP is exceeding its maximum length (16).
  
  =item *
  1007 "INI - QUOTE too long"
  
  The value passed for QUOTE is exceeding its maximum length (16).
  
  =item *
  1008 "INI - SEP undefined"
  
  The value passed for SEP should be defined and not empty.
  
  =item *
  1010 "INI - the header is empty"
  
  The header line parsed in the L</header> is empty.
  
  =item *
  1011 "INI - the header contains more than one valid separator"
  
  The header line parsed in the  L</header>  contains more than one  (unique)
  separator character out of the allowed set of separators.
  
  =item *
  1012 "INI - the header contains an empty field"
  
  The header line parsed in the L</header> contains an empty field.
  
  =item *
  1013 "INI - the header contains nun-unique fields"
  
  The header line parsed in the  L</header>  contains at least  two identical
  fields.
  
  =item *
  1014 "INI - header called on undefined stream"
  
  The header line cannot be parsed from an undefined source.
  
  =item *
  1500 "PRM - Invalid/unsupported argument(s)"
  
  Function or method called with invalid argument(s) or parameter(s).
  
  =item *
  1501 "PRM - The key attribute is passed as an unsupported type"
  
  The C<key> attribute is of an unsupported type.
  
  =item *
  1502 "PRM - The value attribute is passed without the key attribute"
  
  The C<value> attribute is only allowed when a valid key is given.
  
  =item *
  1503 "PRM - The value attribute is passed as an unsupported type"
  
  The C<value> attribute is of an unsupported type.
  
  =item *
  2010 "ECR - QUO char inside quotes followed by CR not part of EOL"
  
  When  L<C<eol>|/eol>  has  been  set  to  anything  but the  default,  like
  C<"\r\t\n">,  and  the  C<"\r">  is  following  the   B<second>   (closing)
  L<C<quote_char>|/quote_char>, where the characters following the C<"\r"> do
  not make up the L<C<eol>|/eol> sequence, this is an error.
  
  =item *
  2011 "ECR - Characters after end of quoted field"
  
  Sequences like C<1,foo,"bar"baz,22,1> are not allowed. C<"bar"> is a quoted
  field and after the closing double-quote, there should be either a new-line
  sequence or a separation character.
  
  =item *
  2012 "EOF - End of data in parsing input stream"
  
  Self-explaining. End-of-file while inside parsing a stream. Can happen only
  when reading from streams with L</getline>,  as using  L</parse> is done on
  strings that are not required to have a trailing L<C<eol>|/eol>.
  
  =item *
  2013 "INI - Specification error for fragments RFC7111"
  
  Invalid specification for URI L</fragment> specification.
  
  =item *
  2014 "ENF - Inconsistent number of fields"
  
  Inconsistent number of fields under strict parsing.
  
  =item *
  2015 "ERW - Empty row"
  
  An empty row was not allowed.
  
  =item *
  2021 "EIQ - NL char inside quotes, binary off"
  
  Sequences like C<1,"foo\nbar",22,1> are allowed only when the binary option
  has been selected with the constructor.
  
  =item *
  2022 "EIQ - CR char inside quotes, binary off"
  
  Sequences like C<1,"foo\rbar",22,1> are allowed only when the binary option
  has been selected with the constructor.
  
  =item *
  2023 "EIQ - QUO character not allowed"
  
  Sequences like C<"foo "bar" baz",qu> and C<2023,",2008-04-05,"Foo, Bar",\n>
  will cause this error.
  
  =item *
  2024 "EIQ - EOF cannot be escaped, not even inside quotes"
  
  The escape character is not allowed as last character in an input stream.
  
  =item *
  2025 "EIQ - Loose unescaped escape"
  
  An escape character should escape only characters that need escaping.
  
  Allowing  the escape  for other characters  is possible  with the attribute
  L</allow_loose_escapes>.
  
  =item *
  2026 "EIQ - Binary character inside quoted field, binary off"
  
  Binary characters are not allowed by default.    Exceptions are fields that
  contain valid UTF-8,  that will automatically be upgraded if the content is
  valid UTF-8. Set L<C<binary>|/binary> to C<1> to accept binary data.
  
  =item *
  2027 "EIQ - Quoted field not terminated"
  
  When parsing a field that started with a quotation character,  the field is
  expected to be closed with a quotation character.   When the parsed line is
  exhausted before the quote is found, that field is not terminated.
  
  =item *
  2030 "EIF - NL char inside unquoted verbatim, binary off"
  
  =item *
  2031 "EIF - CR char is first char of field, not part of EOL"
  
  =item *
  2032 "EIF - CR char inside unquoted, not part of EOL"
  
  =item *
  2034 "EIF - Loose unescaped quote"
  
  =item *
  2035 "EIF - Escaped EOF in unquoted field"
  
  =item *
  2036 "EIF - ESC error"
  
  =item *
  2037 "EIF - Binary character in unquoted field, binary off"
  
  =item *
  2110 "ECB - Binary character in Combine, binary off"
  
  =item *
  2200 "EIO - print to IO failed. See errno"
  
  =item *
  3001 "EHR - Unsupported syntax for column_names ()"
  
  =item *
  3002 "EHR - getline_hr () called before column_names ()"
  
  =item *
  3003 "EHR - bind_columns () and column_names () fields count mismatch"
  
  =item *
  3004 "EHR - bind_columns () only accepts refs to scalars"
  
  =item *
  3006 "EHR - bind_columns () did not pass enough refs for parsed fields"
  
  =item *
  3007 "EHR - bind_columns needs refs to writable scalars"
  
  =item *
  3008 "EHR - unexpected error in bound fields"
  
  =item *
  3009 "EHR - print_hr () called before column_names ()"
  
  =item *
  3010 "EHR - print_hr () called with invalid arguments"
  
  =back
  
  =head1 SEE ALSO
  
  L<Text::CSV_PP>, L<Text::CSV_XS> and L<Text::CSV::Encoded>.
  
  
  =head1 AUTHORS and MAINTAINERS
  
  Alan Citterman F<E<lt>alan[at]mfgrtl.comE<gt>> wrote the original Perl
  module. Please don't send mail concerning Text::CSV to Alan, as
  he's not a present maintainer.
  
  Jochen Wiedmann F<E<lt>joe[at]ispsoft.deE<gt>> rewrote the encoding and
  decoding in C by implementing a simple finite-state machine and added
  the variable quote, escape and separator characters, the binary mode
  and the print and getline methods. See ChangeLog releases 0.10 through
  0.23.
  
  H.Merijn Brand F<E<lt>h.m.brand[at]xs4all.nlE<gt>> cleaned up the code,
  added the field flags methods, wrote the major part of the test suite,
  completed the documentation, fixed some RT bugs. See ChangeLog releases
  0.25 and on.
  
  Makamaka Hannyaharamitu, E<lt>makamaka[at]cpan.orgE<gt> wrote Text::CSV_PP
  which is the pure-Perl version of Text::CSV_XS.
  
  New Text::CSV (since 0.99) is maintained by Makamaka, and Kenichi Ishigaki
  since 1.91.
  
  
  =head1 COPYRIGHT AND LICENSE
  
  Text::CSV
  
  Copyright (C) 1997 Alan Citterman. All rights reserved.
  Copyright (C) 2007-2015 Makamaka Hannyaharamitu.
  Copyright (C) 2017- Kenichi Ishigaki
  A large portion of the doc is taken from Text::CSV_XS. See below.
  
  Text::CSV_PP:
  
  Copyright (C) 2005-2015 Makamaka Hannyaharamitu.
  Copyright (C) 2017- Kenichi Ishigaki
  A large portion of the code/doc are also taken from Text::CSV_XS. See below.
  
  Text:CSV_XS:
  
  Copyright (C) 2007-2016 H.Merijn Brand for PROCURA B.V.
  Copyright (C) 1998-2001 Jochen Wiedmann. All rights reserved.
  Portions Copyright (C) 1997 Alan Citterman. All rights reserved.
  
  
  This library is free software; you can redistribute it and/or modify
  it under the same terms as Perl itself.
  
  =cut
TEXT_CSV

$fatpacked{"Text/CSV_PP.pm"} = '#line '.(1+__LINE__).' "'.__FILE__."\"\n".<<'TEXT_CSV_PP';
  package Text::CSV_PP;
  
  ################################################################################
  #
  # Text::CSV_PP - Text::CSV_XS compatible pure-Perl module
  #
  ################################################################################
  require 5.006001;
  
  use strict;
  use Exporter ();
  use vars qw($VERSION @ISA @EXPORT_OK %EXPORT_TAGS);
  use Carp;
  
  $VERSION = '2.04';
  @ISA = qw(Exporter);
  
  sub PV  { 0 }
  sub IV  { 1 }
  sub NV  { 2 }
  
  sub CSV_TYPE_PV { PV }
  sub CSV_TYPE_IV { IV }
  sub CSV_TYPE_NV { NV }
  
  sub IS_QUOTED () { 0x0001; }
  sub IS_BINARY () { 0x0002; }
  sub IS_ERROR ()  { 0x0004; }
  sub IS_MISSING () { 0x0010; }
  
  sub CSV_FLAGS_IS_QUOTED      { IS_QUOTED }
  sub CSV_FLAGS_IS_BINARY      { IS_BINARY }
  sub CSV_FLAGS_ERROR_IN_FIELD { IS_ERROR }
  sub CSV_FLAGS_IS_MISSING     { IS_MISSING }
  
  sub HOOK_ERROR () { 0x0001; }
  sub HOOK_AFTER_PARSE () { 0x0002; }
  sub HOOK_BEFORE_PRINT () { 0x0004; }
  
  sub useIO_EOF () { 0x0010; }
  
  %EXPORT_TAGS = (
      CONSTANTS => [qw(
          CSV_FLAGS_IS_QUOTED
          CSV_FLAGS_IS_BINARY
          CSV_FLAGS_ERROR_IN_FIELD
          CSV_FLAGS_IS_MISSING
  
          CSV_TYPE_PV
          CSV_TYPE_IV
          CSV_TYPE_NV
      )],
  );
  @EXPORT_OK = (qw(csv PV IV NV), @{$EXPORT_TAGS{'CONSTANTS'}});
  
  my $ERRORS = {
          # Generic errors
          1000 => "INI - constructor failed",
          1001 => "INI - sep_char is equal to quote_char or escape_char",
          1002 => "INI - allow_whitespace with escape_char or quote_char SP or TAB",
          1003 => "INI - \\r or \\n in main attr not allowed",
          1004 => "INI - callbacks should be undef or a hashref",
          1005 => "INI - EOL too long",
          1006 => "INI - SEP too long",
          1007 => "INI - QUOTE too long",
          1008 => "INI - SEP undefined",
  
          1010 => "INI - the header is empty",
          1011 => "INI - the header contains more than one valid separator",
          1012 => "INI - the header contains an empty field",
          1013 => "INI - the header contains nun-unique fields",
          1014 => "INI - header called on undefined stream",
  
          # Syntax errors
          1500 => "PRM - Invalid/unsupported arguments(s)",
          1501 => "PRM - The key attribute is passed as an unsupported type",
          1502 => "PRM - The value attribute is passed without the key attribute",
          1503 => "PRM - The value attribute is passed as an unsupported type",
  
          # Parse errors
          2010 => "ECR - QUO char inside quotes followed by CR not part of EOL",
          2011 => "ECR - Characters after end of quoted field",
          2012 => "EOF - End of data in parsing input stream",
          2013 => "ESP - Specification error for fragments RFC7111",
          2014 => "ENF - Inconsistent number of fields",
          2015 => "ERW - Empty row",
  
          # EIQ - Error Inside Quotes
          2021 => "EIQ - NL char inside quotes, binary off",
          2022 => "EIQ - CR char inside quotes, binary off",
          2023 => "EIQ - QUO character not allowed",
          2024 => "EIQ - EOF cannot be escaped, not even inside quotes",
          2025 => "EIQ - Loose unescaped escape",
          2026 => "EIQ - Binary character inside quoted field, binary off",
          2027 => "EIQ - Quoted field not terminated",
  
          # EIF - Error Inside Field
          2030 => "EIF - NL char inside unquoted verbatim, binary off",
          2031 => "EIF - CR char is first char of field, not part of EOL",
          2032 => "EIF - CR char inside unquoted, not part of EOL",
          2034 => "EIF - Loose unescaped quote",
          2035 => "EIF - Escaped EOF in unquoted field",
          2036 => "EIF - ESC error",
          2037 => "EIF - Binary character in unquoted field, binary off",
  
          # Combine errors
          2110 => "ECB - Binary character in Combine, binary off",
  
          # IO errors
          2200 => "EIO - print to IO failed. See errno",
  
          # Hash-Ref errors
          3001 => "EHR - Unsupported syntax for column_names ()",
          3002 => "EHR - getline_hr () called before column_names ()",
          3003 => "EHR - bind_columns () and column_names () fields count mismatch",
          3004 => "EHR - bind_columns () only accepts refs to scalars",
          3006 => "EHR - bind_columns () did not pass enough refs for parsed fields",
          3007 => "EHR - bind_columns needs refs to writable scalars",
          3008 => "EHR - unexpected error in bound fields",
          3009 => "EHR - print_hr () called before column_names ()",
          3010 => "EHR - print_hr () called with invalid arguments",
  
          4001 => "PRM - The key does not exist as field in the data",
  
          5001 => "PRM - The result does not match the output to append to",
          5002 => "PRM - Unsupported output",
  
          0    => "",
  };
  
  BEGIN {
      if ( $] < 5.006 ) {
          $INC{'bytes.pm'} = 1 unless $INC{'bytes.pm'}; # dummy
          no strict 'refs';
          *{"utf8::is_utf8"} = sub { 0; };
          *{"utf8::decode"}  = sub { };
      }
      elsif ( $] < 5.008 ) {
          no strict 'refs';
          *{"utf8::is_utf8"} = sub { 0; };
          *{"utf8::decode"}  = sub { };
          *{"utf8::encode"}  = sub { };
      }
      elsif ( !defined &utf8::is_utf8 ) {
         require Encode;
         *utf8::is_utf8 = *Encode::is_utf8;
      }
  
      eval q| require Scalar::Util |;
      if ( $@ ) {
          eval q| require B |;
          if ( $@ ) {
              Carp::croak $@;
          }
          else {
              my %tmap = qw(
                  B::NULL   SCALAR
                  B::HV     HASH
                  B::AV     ARRAY
                  B::CV     CODE
                  B::IO     IO
                  B::GV     GLOB
                  B::REGEXP REGEXP
              );
              *Scalar::Util::reftype = sub (\$) {
                  my $r = shift;
                  return undef unless length(ref($r));
                  my $t = ref(B::svref_2object($r));
                  return
                      exists $tmap{$t} ? $tmap{$t}
                    : length(ref($$r)) ? 'REF'
                    :                    'SCALAR';
              };
              *Scalar::Util::readonly = sub (\$) {
                  my $b = B::svref_2object( $_[0] );
                  $b->FLAGS & 0x00800000; # SVf_READONLY?
              };
          }
      }
  }
  
  ################################################################################
  #
  # Common pure perl methods, taken almost directly from Text::CSV_XS.
  # (These should be moved into a common class eventually, so that
  # both XS and PP don't need to apply the same changes.)
  #
  ################################################################################
  
  ################################################################################
  # version
  ################################################################################
  
  sub version {
      return $VERSION;
  }
  
  ################################################################################
  # new
  ################################################################################
  
  my %def_attr = (
      eol				=> '',
      sep_char			=> ',',
      quote_char			=> '"',
      escape_char			=> '"',
      binary			=> 0,
      decode_utf8			=> 1,
      auto_diag			=> 0,
      diag_verbose		=> 0,
      strict              => 0,
      blank_is_undef		=> 0,
      empty_is_undef		=> 0,
      allow_whitespace		=> 0,
      allow_loose_quotes		=> 0,
      allow_loose_escapes		=> 0,
      allow_unquoted_escape	=> 0,
      always_quote		=> 0,
      quote_empty			=> 0,
      quote_space			=> 1,
      quote_binary		=> 1,
      escape_null			=> 1,
      keep_meta_info		=> 0,
      verbatim			=> 0,
      formula			=> 0,
      skip_empty_rows => 0,
      undef_str			=> undef,
      comment_str     => undef,
      types			=> undef,
      callbacks			=> undef,
  
      _EOF			=> 0,
      _RECNO			=> 0,
      _STATUS			=> undef,
      _FIELDS			=> undef,
      _FFLAGS			=> undef,
      _STRING			=> undef,
      _ERROR_INPUT		=> undef,
      _COLUMN_NAMES		=> undef,
      _BOUND_COLUMNS		=> undef,
      _AHEAD			=> undef,
      _FORMULA_CB     => undef,
      _EMPTROW_CB     => undef,
  
      ENCODING			=> undef,
  );
  
  my %attr_alias = (
      quote_always		=> "always_quote",
      verbose_diag		=> "diag_verbose",
      quote_null			=> "escape_null",
      escape			=> "escape_char",
      comment         => "comment_str",
      );
  
  my $last_new_error = Text::CSV_PP->SetDiag(0);
  my $ebcdic         = ord("A") == 0xC1;  # Faster than $Config{'ebcdic'}
  my @internal_kh;
  my $last_error;
  
  # NOT a method: is also used before bless
  sub _unhealthy_whitespace {
      my ($self, $aw) = @_;
      $aw or return 0; # no checks needed without allow_whitespace
  
      my $quo = $self->{quote};
      defined $quo && length ($quo) or $quo = $self->{quote_char};
      my $esc = $self->{escape_char};
  
      defined $quo && $quo =~ m/^[ \t]/ and return 1002;
      defined $esc && $esc =~ m/^[ \t]/ and return 1002;
  
      return 0;
      }
  
  sub _check_sanity {
      my $self = shift;
  
      my $eol = $self->{eol};
      my $sep = $self->{sep};
      defined $sep && length ($sep) or $sep = $self->{sep_char};
      my $quo = $self->{quote};
      defined $quo && length ($quo) or $quo = $self->{quote_char};
      my $esc = $self->{escape_char};
  
  #    use DP;::diag ("SEP: '", DPeek ($sep),
  #                "', QUO: '", DPeek ($quo),
  #                "', ESC: '", DPeek ($esc),"'");
  
      # sep_char should not be undefined
      $sep ne ""         or  return 1008;
      length ($sep) > 16     and return 1006;
      $sep =~ m/[\r\n]/      and return 1003;
  
      if (defined $quo) {
          $quo eq $sep        and return 1001;
          length ($quo) > 16  and return 1007;
          $quo =~ m/[\r\n]/   and return 1003;
          }
      if (defined $esc) {
          $esc eq $sep        and return 1001;
          $esc =~ m/[\r\n]/   and return 1003;
          }
      if (defined $eol) {
          length ($eol) > 16  and return 1005;
          }
  
      return _unhealthy_whitespace ($self, $self->{allow_whitespace});
      }
  
  sub known_attributes {
      sort grep !m/^_/ => "sep", "quote", keys %def_attr;
      }
  
  sub new {
      $last_new_error   = Text::CSV_PP->SetDiag(1000,
          'usage: my $csv = Text::CSV_PP->new ([{ option => value, ... }]);');
  
      my $proto = shift;
      my $class = ref $proto || $proto	or  return;
      @_ > 0 &&   ref $_[0] ne "HASH"	and return;
      my $attr  = shift || {};
      my %attr  = map {
          my $k = m/^[a-zA-Z]\w+$/ ? lc $_ : $_;
          exists $attr_alias{$k} and $k = $attr_alias{$k};
          ($k => $attr->{$_});
          } keys %$attr;
  
      my $sep_aliased = 0;
      if (exists $attr{sep}) {
          $attr{sep_char} = delete $attr{sep};
          $sep_aliased = 1;
          }
      my $quote_aliased = 0;
      if (exists $attr{quote}) {
          $attr{quote_char} = delete $attr{quote};
          $quote_aliased = 1;
          }
      exists $attr{formula_handling} and
          $attr{formula} = delete $attr{formula_handling};
      my $attr_formula = delete $attr{formula};
  
      for (keys %attr) {
          if (m/^[a-z]/ && exists $def_attr{$_}) {
              # uncoverable condition false
              defined $attr{$_} && m/_char$/ and utf8::decode ($attr{$_});
              next;
              }
  #        croak?
          $last_new_error = Text::CSV_PP->SetDiag(1000, "INI - Unknown attribute '$_'");
          $attr{auto_diag} and error_diag ();
          return;
          }
      if ($sep_aliased) {
          my @b = unpack "U0C*", $attr{sep_char};
          if (@b > 1) {
              $attr{sep} = $attr{sep_char};
              $attr{sep_char} = "\0";
              }
          else {
              $attr{sep} = undef;
              }
          }
      if ($quote_aliased and defined $attr{quote_char}) {
          my @b = unpack "U0C*", $attr{quote_char};
          if (@b > 1) {
              $attr{quote} = $attr{quote_char};
              $attr{quote_char} = "\0";
              }
          else {
              $attr{quote} = undef;
              }
          }
  
      my $self = { %def_attr, %attr };
      if (my $ec = _check_sanity ($self)) {
          $last_new_error   = Text::CSV_PP->SetDiag($ec);
          $attr{auto_diag} and error_diag ();
          return;
          }
      if (defined $self->{callbacks} && ref $self->{callbacks} ne "HASH") {
          Carp::carp "The 'callbacks' attribute is set but is not a hash: ignored\n";
          $self->{callbacks} = undef;
          }
  
      $last_new_error = Text::CSV_PP->SetDiag(0);
      defined $\ && !exists $attr{eol} and $self->{eol} = $\;
      bless $self, $class;
      defined $self->{'types'}           and $self->types($self->{'types'});
      defined $self->{'skip_empty_rows'} and $self->{'skip_empty_rows'} = _supported_skip_empty_rows($self, $self->{'skip_empty_rows'});
      defined $attr_formula              and $self->{'formula'}         = _supported_formula($self, $attr_formula);
      $self;
  }
  
  # Keep in sync with XS!
  my %_cache_id = ( # Only expose what is accessed from within PM
      quote_char			=>  0,
      escape_char			=>  1,
      sep_char			=>  2,
      sep				=> 39,	# 39 .. 55
      binary			=>  3,
      keep_meta_info		=>  4,
      always_quote		=>  5,
      allow_loose_quotes		=>  6,
      allow_loose_escapes		=>  7,
      allow_unquoted_escape	=>  8,
      allow_whitespace		=>  9,
      blank_is_undef		=> 10,
      eol				=> 11,
      quote			=> 15,
      verbatim			=> 22,
      empty_is_undef		=> 23,
      auto_diag			=> 24,
      diag_verbose		=> 33,
      quote_space			=> 25,
      quote_empty			=> 37,
      quote_binary		=> 32,
      escape_null			=> 31,
      decode_utf8			=> 35,
      _has_ahead			=> 30,
      _has_hooks			=> 36,
      _is_bound			=> 26,	# 26 .. 29
      formula			=> 38,
      strict   			=> 42,
      skip_empty_rows     => 43,
      undef_str  		=> 46,
      comment_str     => 54,
      types           => 62,
      );
  
  my %_hidden_cache_id = qw(
      sep_len		38
      eol_len		12
      eol_is_cr		13
      quo_len		16
      has_error_input		34
  );
  
  my %_reverse_cache_id = (
      map({$_cache_id{$_} => $_} keys %_cache_id),
      map({$_hidden_cache_id{$_} => $_} keys %_hidden_cache_id),
  );
  
  # A `character'
  sub _set_attr_C {
      my ($self, $name, $val, $ec) = @_;
      defined $val and utf8::decode($val);
      $self->{$name} = $val;
      $ec = _check_sanity ($self) and croak ($self->SetDiag ($ec));
      $self->_cache_set ($_cache_id{$name}, $val);
      }
  
  # A flag
  sub _set_attr_X {
      my ($self, $name, $val) = @_;
      defined $val or $val = 0;
      $self->{$name} = $val;
      $self->_cache_set ($_cache_id{$name}, 0 + $val);
      }
  
  # A number
  sub _set_attr_N {
      my ($self, $name, $val) = @_;
      $self->{$name} = $val;
      $self->_cache_set ($_cache_id{$name}, 0 + $val);
      }
  
  # Accessor methods.
  #   It is unwise to change them halfway through a single file!
  sub quote_char {
      my $self = shift;
      if (@_) {
          $self->_set_attr_C ("quote_char", shift);
          $self->_cache_set ($_cache_id{quote}, "");
          }
      $self->{quote_char};
      }
  
  sub quote {
      my $self = shift;
      if (@_) {
          my $quote = shift;
          defined $quote or $quote = "";
          utf8::decode ($quote);
          my @b = unpack "U0C*", $quote;
          if (@b > 1) {
              @b > 16 and croak ($self->SetDiag (1007));
              $self->quote_char ("\0");
              }
          else {
              $self->quote_char ($quote);
              $quote = "";
              }
          $self->{quote} = $quote;
  
          my $ec = _check_sanity ($self);
          $ec and croak ($self->SetDiag ($ec));
  
          $self->_cache_set ($_cache_id{quote}, $quote);
          }
      my $quote = $self->{quote};
      defined $quote && length ($quote) ? $quote : $self->{quote_char};
      }
  
  sub escape_char {
      my $self = shift;
      if (@_) {
          my $ec = shift;
          $self->_set_attr_C ("escape_char", $ec);
          $ec or $self->_set_attr_X ("escape_null", 0);
          }
      $self->{escape_char};
      }
  
  sub sep_char {
      my $self = shift;
      if (@_) {
          $self->_set_attr_C ("sep_char", shift);
          $self->_cache_set ($_cache_id{sep}, "");
          }
      $self->{sep_char};
  }
  
  sub sep {
      my $self = shift;
      if (@_) {
          my $sep = shift;
          defined $sep or $sep = "";
          utf8::decode ($sep);
          my @b = unpack "U0C*", $sep;
          if (@b > 1) {
              @b > 16 and croak ($self->SetDiag (1006));
              $self->sep_char ("\0");
              }
          else {
              $self->sep_char ($sep);
              $sep = "";
              }
          $self->{sep} = $sep;
  
          my $ec = _check_sanity ($self);
          $ec and croak ($self->SetDiag ($ec));
  
          $self->_cache_set ($_cache_id{sep}, $sep);
          }
      my $sep = $self->{sep};
      defined $sep && length ($sep) ? $sep : $self->{sep_char};
      }
  
  sub eol {
      my $self = shift;
      if (@_) {
          my $eol = shift;
          defined $eol or $eol = "";
          length ($eol) > 16 and croak ($self->SetDiag (1005));
          $self->{eol} = $eol;
          $self->_cache_set ($_cache_id{eol}, $eol);
          }
      $self->{eol};
      }
  
  sub always_quote {
      my $self = shift;
      @_ and $self->_set_attr_X ("always_quote", shift);
      $self->{always_quote};
      }
  
  sub quote_space {
      my $self = shift;
      @_ and $self->_set_attr_X ("quote_space", shift);
      $self->{quote_space};
      }
  
  sub quote_empty {
      my $self = shift;
      @_ and $self->_set_attr_X ("quote_empty", shift);
      $self->{quote_empty};
      }
  
  sub escape_null {
      my $self = shift;
      @_ and $self->_set_attr_X ("escape_null", shift);
      $self->{escape_null};
      }
  
  sub quote_null { goto &escape_null; }
  
  sub quote_binary {
      my $self = shift;
      @_ and $self->_set_attr_X ("quote_binary", shift);
      $self->{quote_binary};
      }
  
  sub binary {
      my $self = shift;
      @_ and $self->_set_attr_X ("binary", shift);
      $self->{binary};
      }
  
  sub strict {
      my $self = shift;
      @_ and $self->_set_attr_X ("strict", shift);
      $self->{strict};
      }
  
  sub _supported_skip_empty_rows {
      my ($self, $f) = @_;
      defined $f or return 0;
      if ($self && $f && ref $f && ref $f eq "CODE") {
         $self->{'_EMPTROW_CB'} = $f;
         return 6;
         }
      $f =~ m/^(?: 0 | undef         )$/xi ? 0 :
      $f =~ m/^(?: 1 | skip          )$/xi ? 1 :
      $f =~ m/^(?: 2 | eof   | stop  )$/xi ? 2 :
      $f =~ m/^(?: 3 | die           )$/xi ? 3 :
      $f =~ m/^(?: 4 | croak         )$/xi ? 4 :
      $f =~ m/^(?: 5 | error         )$/xi ? 5 :
      $f =~ m/^(?: 6 | cb            )$/xi ? 6 : do {
         $self ||= "Text::CSV_PP";
         croak ($self->_SetDiagInfo (1500, "skip_empty_rows '$f' is not supported"));
         };
      }
  
   sub skip_empty_rows {
      my $self = shift;
      @_ and $self->_set_attr_N ("skip_empty_rows", _supported_skip_empty_rows ($self, shift));
      my $ser = $self->{'skip_empty_rows'};
      $ser == 6 or $self->{'_EMPTROW_CB'} = undef;
      $ser <= 1 ? $ser : $ser == 2 ? "eof"   : $ser == 3 ? "die"   :
                        $ser == 4 ? "croak" : $ser == 5 ? "error" :
                        $self->{'_EMPTROW_CB'};
      }
  
  sub _SetDiagInfo {
       my ($self, $err, $msg) = @_;
       $self->SetDiag ($err);
       my $em  = $self->error_diag;
       $em =~ s/^\d+$// and $msg =~ s/^/# /;
       my $sep = $em =~ m/[;\n]$/ ? "\n\t" : ": ";
       join $sep => grep m/\S\S\S/ => $em, $msg;
       }
  
  sub _supported_formula {
      my ($self, $f) = @_;
      defined $f or return 5;
      if ($self && $f && ref $f && ref $f eq "CODE") {
      $self->{_FORMULA_CB} = $f;
      return 6;
      }
      $f =~ m/^(?: 0 | none    )$/xi ? 0 :
      $f =~ m/^(?: 1 | die     )$/xi ? 1 :
      $f =~ m/^(?: 2 | croak   )$/xi ? 2 :
      $f =~ m/^(?: 3 | diag    )$/xi ? 3 :
      $f =~ m/^(?: 4 | empty | )$/xi ? 4 :
      $f =~ m/^(?: 5 | undef   )$/xi ? 5 :
      $f =~ m/^(?: 6 | cb      )$/xi ? 6 : do {
          $self ||= "Text::CSV_PP";
          croak ($self->_SetDiagInfo (1500, "formula-handling '$f' is not supported"));
          };
      }
  
  sub formula {
      my $self = shift;
      @_ and $self->_set_attr_N ("formula", _supported_formula ($self, shift));
      $self->{formula} == 6 or $self->{_FORMULA_CB} = undef;
      [qw( none die croak diag empty undef cb )]->[_supported_formula ($self, $self->{formula})];
      }
  sub formula_handling {
      my $self = shift;
      $self->formula (@_);
      }
  
  sub decode_utf8 {
      my $self = shift;
      @_ and $self->_set_attr_X ("decode_utf8", shift);
      $self->{decode_utf8};
  }
  
  sub keep_meta_info {
      my $self = shift;
      if (@_) {
          my $v = shift;
          !defined $v || $v eq "" and $v = 0;
          $v =~ m/^[0-9]/ or $v = lc $v eq "false" ? 0 : 1; # true/truth = 1
          $self->_set_attr_X ("keep_meta_info", $v);
          }
      $self->{keep_meta_info};
      }
  
  sub allow_loose_quotes {
      my $self = shift;
      @_ and $self->_set_attr_X ("allow_loose_quotes", shift);
      $self->{allow_loose_quotes};
      }
  
  sub allow_loose_escapes {
      my $self = shift;
      @_ and $self->_set_attr_X ("allow_loose_escapes", shift);
      $self->{allow_loose_escapes};
      }
  
  sub allow_whitespace {
      my $self = shift;
      if (@_) {
          my $aw = shift;
          _unhealthy_whitespace ($self, $aw) and
              croak ($self->SetDiag (1002));
          $self->_set_attr_X ("allow_whitespace", $aw);
          }
      $self->{allow_whitespace};
      }
  
  sub allow_unquoted_escape {
      my $self = shift;
      @_ and $self->_set_attr_X ("allow_unquoted_escape", shift);
      $self->{allow_unquoted_escape};
      }
  
  sub blank_is_undef {
      my $self = shift;
      @_ and $self->_set_attr_X ("blank_is_undef", shift);
      $self->{blank_is_undef};
      }
  
  sub empty_is_undef {
      my $self = shift;
      @_ and $self->_set_attr_X ("empty_is_undef", shift);
      $self->{empty_is_undef};
      }
  
  sub verbatim {
      my $self = shift;
      @_ and $self->_set_attr_X ("verbatim", shift);
      $self->{verbatim};
      }
  
  sub undef_str {
      my $self = shift;
      if (@_) {
          my $v = shift;
          $self->{undef_str} = defined $v ? "$v" : undef;
          $self->_cache_set ($_cache_id{undef_str}, $self->{undef_str});
          }
      $self->{undef_str};
      }
  
  sub comment_str {
      my $self = shift;
      if (@_) {
          my $v = shift;
          $self->{comment_str} = defined $v ? "$v" : undef;
          $self->_cache_set ($_cache_id{comment_str}, $self->{comment_str});
          }
      $self->{comment_str};
      }
  
  sub auto_diag {
      my $self = shift;
      if (@_) {
          my $v = shift;
          !defined $v || $v eq "" and $v = 0;
          $v =~ m/^[0-9]/ or $v = lc $v eq "false" ? 0 : 1; # true/truth = 1
          $self->_set_attr_X ("auto_diag", $v);
          }
      $self->{auto_diag};
      }
  
  sub diag_verbose {
      my $self = shift;
      if (@_) {
          my $v = shift;
          !defined $v || $v eq "" and $v = 0;
          $v =~ m/^[0-9]/ or $v = lc $v eq "false" ? 0 : 1; # true/truth = 1
          $self->_set_attr_X ("diag_verbose", $v);
          }
      $self->{diag_verbose};
      }
  
  ################################################################################
  # status
  ################################################################################
  
  sub status {
      $_[0]->{_STATUS};
  }
  
  sub eof {
      $_[0]->{_EOF};
  }
  
  sub types {
      my $self = shift;
  
      if (@_) {
          if (my $types = shift) {
              $self->{'_types'} = join("", map{ chr($_) } @$types);
              $self->{'types'} = $types;
              $self->_cache_set ($_cache_id{'types'}, $self->{'_types'});
          }
          else {
              delete $self->{'types'};
              delete $self->{'_types'};
              $self->_cache_set ($_cache_id{'types'}, undef);
              undef;
          }
      }
      else {
          $self->{'types'};
      }
  }
  
  sub callbacks {
      my $self = shift;
      if (@_) {
          my $cb;
          my $hf = 0x00;
          if (defined $_[0]) {
              grep { !defined } @_ and croak ($self->SetDiag (1004));
              $cb = @_ == 1 && ref $_[0] eq "HASH" ? shift
                  : @_ % 2 == 0                    ? { @_ }
                  : croak ($self->SetDiag (1004));
              foreach my $cbk (keys %$cb) {
                  # A key cannot be a ref. That would be stored as the *string
                  # 'SCALAR(0x1f3e710)' or 'ARRAY(0x1a5ae18)'
                  $cbk =~ m/^[\w.]+$/ && ref $cb->{$cbk} eq "CODE" or
                      croak ($self->SetDiag (1004));
                  }
              exists $cb->{error}        and $hf |= 0x01;
              exists $cb->{after_parse}  and $hf |= 0x02;
              exists $cb->{before_print} and $hf |= 0x04;
              }
          elsif (@_ > 1) {
              # (undef, whatever)
              croak ($self->SetDiag (1004));
              }
          $self->_set_attr_X ("_has_hooks", $hf);
          $self->{callbacks} = $cb;
          }
      $self->{callbacks};
      }
  
  ################################################################################
  # error_diag
  ################################################################################
  
  sub error_diag {
      my $self = shift;
      my @diag = (0 + $last_new_error, $last_new_error, 0, 0, 0);
  
      # Docs state to NEVER use UNIVERSAL::isa, because it will *never* call an
      # overridden isa method in any class. Well, that is exacly what I want here
      if ($self && ref $self && # Not a class method or direct call
          UNIVERSAL::isa ($self, __PACKAGE__) && exists $self->{_ERROR_DIAG}) {
          $diag[0] = 0 + $self->{_ERROR_DIAG};
          $diag[1] =     $self->{_ERROR_DIAG};
          $diag[2] = 1 + $self->{_ERROR_POS} if exists $self->{_ERROR_POS};
          $diag[3] =     $self->{_RECNO};
          $diag[4] =     $self->{_ERROR_FLD} if exists $self->{_ERROR_FLD};
  
          $diag[0] && $self->{callbacks} && $self->{callbacks}{error} and
              return $self->{callbacks}{error}->(@diag);
          }
  
      my $context = wantarray;
  
      unless (defined $context) {	# Void context, auto-diag
          if ($diag[0] && $diag[0] != 2012) {
              my $msg = "# CSV_PP ERROR: $diag[0] - $diag[1] \@ rec $diag[3] pos $diag[2]\n";
              $diag[4] and $msg =~ s/$/ field $diag[4]/;
  
              unless ($self && ref $self) {        # auto_diag
                      # called without args in void context
                  warn $msg;
                  return;
                  }
  
              $self->{diag_verbose} and $self->{_ERROR_INPUT} and
              $msg .= "$self->{_ERROR_INPUT}'\n".
                  (" " x ($diag[2] - 1))."^\n";
  
              my $lvl = $self->{auto_diag};
              if ($lvl < 2) {
                  my @c = caller (2);
                  if (@c >= 11 && $c[10] && ref $c[10] eq "HASH") {
                      my $hints = $c[10];
                      (exists $hints->{autodie} && $hints->{autodie} or
                       exists $hints->{"guard Fatal"} &&
                      !exists $hints->{"no Fatal"}) and
                          $lvl++;
                      # Future releases of autodie will probably set $^H{autodie}
                      #  to "autodie @args", like "autodie :all" or "autodie open"
                      #  so we can/should check for "open" or "new"
                      }
                  }
              $lvl > 1 ? die $msg : warn $msg;
              }
          return;
          }
  
      return $context ? @diag : $diag[1];
  }
  
  sub record_number {
      return shift->{_RECNO};
  }
  
  ################################################################################
  # string
  ################################################################################
  
  *string = \&_string;
  sub _string {
      defined $_[0]->{_STRING} ? ${ $_[0]->{_STRING} } : undef;
  }
  
  ################################################################################
  # fields
  ################################################################################
  
  *fields = \&_fields;
  sub _fields {
      ref($_[0]->{_FIELDS}) ?  @{$_[0]->{_FIELDS}} : undef;
  }
  
  ################################################################################
  # meta_info
  ################################################################################
  
  sub meta_info {
      $_[0]->{_FFLAGS} ? @{ $_[0]->{_FFLAGS} } : undef;
  }
  
  sub is_quoted {
      return unless (defined $_[0]->{_FFLAGS});
      return if( $_[1] =~ /\D/ or $_[1] < 0 or  $_[1] > $#{ $_[0]->{_FFLAGS} } );
  
      $_[0]->{_FFLAGS}->[$_[1]] & IS_QUOTED ? 1 : 0;
  }
  
  sub is_binary {
      return unless (defined $_[0]->{_FFLAGS});
      return if( $_[1] =~ /\D/ or $_[1] < 0 or  $_[1] > $#{ $_[0]->{_FFLAGS} } );
      $_[0]->{_FFLAGS}->[$_[1]] & IS_BINARY ? 1 : 0;
  }
  
  sub is_missing {
      my ($self, $idx, $val) = @_;
      return unless $self->{keep_meta_info}; # FIXME
      $idx < 0 || !ref $self->{_FFLAGS} and return;
      $idx >= @{$self->{_FFLAGS}} and return 1;
      $self->{_FFLAGS}[$idx] & IS_MISSING ? 1 : 0;
  }
  
  ################################################################################
  # combine
  ################################################################################
  *combine = \&_combine;
  sub _combine {
      my ($self, @fields) = @_;
      my $str  = "";
      $self->{_FIELDS} = \@fields;
      $self->{_STATUS} = (@fields > 0) && $self->__combine(\$str, \@fields, 0);
      $self->{_STRING} = \$str;
      $self->{_STATUS};
      }
  
  ################################################################################
  # parse
  ################################################################################
  *parse = \&_parse;
  sub _parse {
      my ($self, $str) = @_;
  
      ref $str and croak ($self->SetDiag (1500));
  
      my $fields = [];
      my $fflags = [];
      $self->{_STRING} = \$str;
      if (defined $str && $self->__parse ($fields, $fflags, $str, 0)) {
          $self->{_FIELDS} = $fields;
          $self->{_FFLAGS} = $fflags;
          $self->{_STATUS} = 1;
          }
      else {
          $self->{_FIELDS} = undef;
          $self->{_FFLAGS} = undef;
          $self->{_STATUS} = 0;
          }
      $self->{_STATUS};
      }
  
  sub column_names {
      my ( $self, @columns ) = @_;
  
      @columns or return defined $self->{_COLUMN_NAMES} ? @{$self->{_COLUMN_NAMES}} : ();
      @columns == 1 && ! defined $columns[0] and return $self->{_COLUMN_NAMES} = undef;
  
      if ( @columns == 1 && ref $columns[0] eq "ARRAY" ) {
          @columns = @{ $columns[0] };
      }
      elsif ( join "", map { defined $_ ? ref $_ : "" } @columns ) {
          croak $self->SetDiag( 3001 );
      }
  
      if ( $self->{_BOUND_COLUMNS} && @columns != @{$self->{_BOUND_COLUMNS}} ) {
          croak $self->SetDiag( 3003 );
      }
  
      $self->{_COLUMN_NAMES} = [ map { defined $_ ? $_ : "\cAUNDEF\cA" } @columns ];
      @{ $self->{_COLUMN_NAMES} };
  }
  
  sub header {
      my ($self, $fh, @args) = @_;
  
      $fh or croak ($self->SetDiag (1014));
  
      my (@seps, %args);
      for (@args) {
          if (ref $_ eq "ARRAY") {
              push @seps, @$_;
              next;
              }
          if (ref $_ eq "HASH") {
              %args = %$_;
              next;
              }
          croak (q{usage: $csv->header ($fh, [ seps ], { options })});
          }
  
      defined $args{munge} && !defined $args{munge_column_names} and
          $args{munge_column_names} = $args{munge}; # munge as alias
      defined $args{detect_bom}         or $args{detect_bom}         = 1;
      defined $args{set_column_names}   or $args{set_column_names}   = 1;
      defined $args{munge_column_names} or $args{munge_column_names} = "lc";
  
      # Reset any previous leftovers
      $self->{_RECNO}        = 0;
      $self->{_AHEAD}        = undef;
      $self->{_COLUMN_NAMES} = undef if $args{set_column_names};
      $self->{_BOUND_COLUMNS}    = undef if $args{set_column_names};
      $self->_cache_set($_cache_id{'_has_ahead'}, 0);
  
      if (defined $args{sep_set}) {
          ref $args{sep_set} eq "ARRAY" or
              croak ($self->_SetDiagInfo (1500, "sep_set should be an array ref"));
          @seps =  @{$args{sep_set}};
      }
  
      $^O eq "MSWin32" and binmode $fh;
      my $hdr = <$fh>;
      # check if $hdr can be empty here, I don't think so
      defined $hdr && $hdr ne "" or croak ($self->SetDiag (1010));
  
      my %sep;
      @seps or @seps = (",", ";");
      foreach my $sep (@seps) {
          index ($hdr, $sep) >= 0 and $sep{$sep}++;
          }
  
      keys %sep >= 2 and croak ($self->SetDiag (1011));
  
      $self->sep (keys %sep);
      my $enc = "";
      if ($args{detect_bom}) { # UTF-7 is not supported
             if ($hdr =~ s/^\x00\x00\xfe\xff//) { $enc = "utf-32be"   }
          elsif ($hdr =~ s/^\xff\xfe\x00\x00//) { $enc = "utf-32le"   }
          elsif ($hdr =~ s/^\xfe\xff//)         { $enc = "utf-16be"   }
          elsif ($hdr =~ s/^\xff\xfe//)         { $enc = "utf-16le"   }
          elsif ($hdr =~ s/^\xef\xbb\xbf//)     { $enc = "utf-8"      }
          elsif ($hdr =~ s/^\xf7\x64\x4c//)     { $enc = "utf-1"      }
          elsif ($hdr =~ s/^\xdd\x73\x66\x73//) { $enc = "utf-ebcdic" }
          elsif ($hdr =~ s/^\x0e\xfe\xff//)     { $enc = "scsu"       }
          elsif ($hdr =~ s/^\xfb\xee\x28//)     { $enc = "bocu-1"     }
          elsif ($hdr =~ s/^\x84\x31\x95\x33//) { $enc = "gb-18030"   }
          elsif ($hdr =~ s/^\x{feff}//)         { $enc = ""           }
  
          $self->{ENCODING} = $enc ? uc $enc : undef;
  
          $hdr eq "" and croak ($self->SetDiag (1010));
  
          if ($enc) {
              $ebcdic && $enc eq "utf-ebcdic" and $enc = "";
              if ($enc =~ m/([13]).le$/) {
                  my $l = 0 + $1;
                  my $x;
                  $hdr .= "\0" x $l;
                  read $fh, $x, $l;
                  }
              if ($enc) {
              if ($enc ne "utf-8") {
                 require Encode;
                 $hdr = Encode::decode ($enc, $hdr);
                 }
              binmode $fh, ":encoding($enc)";
              }
              }
          }
  
      my ($ahead, $eol);
      if ($hdr and $hdr =~ s/\Asep=(\S)([\r\n]+)//i) { # Also look in xs:Parse
          $self->sep ($1);
          length $hdr or $hdr = <$fh>;
      }
  
      if ($hdr =~ s/^([^\r\n]+)([\r\n]+)([^\r\n].+)\z/$1/s) {
          $eol   = $2;
          $ahead = $3;
      }
  
      my $hr = \$hdr; # Will cause croak on perl-5.6.x
      open my $h, "<", $hr or croak ($self->SetDiag (1010));
  
      my $row = $self->getline ($h) or croak;
      close $h;
  
      if (   $args{'munge_column_names'} eq "lc") {
          $_ = lc for @{$row};
      }
      elsif ($args{'munge_column_names'} eq "uc") {
          $_ = uc for @{$row};
      }
      elsif ($args{'munge_column_names'} eq "db") {
          for (@{$row}) {
              s/\W+/_/g;
              s/^_+//;
              $_ = lc;
          }
      }
  
      if ($ahead) { # Must be after getline, which creates the cache
          $self->_cache_set ($_cache_id{_has_ahead}, 1);
          $self->{_AHEAD} = $ahead;
          $eol =~ m/^\r([^\n]|\z)/ and $self->eol ($eol);
          }
  
      my @hdr = @$row;
      ref $args{munge_column_names} eq "CODE" and
          @hdr = map { $args{munge_column_names}->($_)       } @hdr;
      ref $args{munge_column_names} eq "HASH" and
          @hdr = map { $args{munge_column_names}->{$_} || $_ } @hdr;
      my %hdr; $hdr{$_}++ for @hdr;
      exists $hdr{''} and croak ($self->SetDiag (1012));
      unless (keys %hdr == @hdr) {
          croak ($self->_SetDiagInfo (1013, join ", " =>
              map { "$_ ($hdr{$_})" } grep { $hdr{$_} > 1 } keys %hdr));
          }
      $args{set_column_names} and $self->column_names (@hdr);
      wantarray ? @hdr : $self;
      }
  
  sub bind_columns {
      my ( $self, @refs ) = @_;
  
      @refs or return defined $self->{_BOUND_COLUMNS} ? @{$self->{_BOUND_COLUMNS}} : undef;
      @refs == 1 && ! defined $refs[0] and return $self->{_BOUND_COLUMNS} = undef;
  
      if ( $self->{_COLUMN_NAMES} && @refs != @{$self->{_COLUMN_NAMES}} ) {
          croak $self->SetDiag( 3003 );
      }
  
      if ( grep { ref $_ ne "SCALAR" } @refs ) { # why don't use grep?
          croak $self->SetDiag( 3004 );
      }
  
      $self->_set_attr_N("_is_bound", scalar @refs);
      $self->{_BOUND_COLUMNS} = [ @refs ];
      @refs;
  }
  
  sub getline_hr {
      my ($self, @args, %hr) = @_;
      $self->{_COLUMN_NAMES} or croak ($self->SetDiag (3002));
      my $fr = $self->getline (@args) or return;
      if (ref $self->{_FFLAGS}) { # missing
          $self->{_FFLAGS}[$_] = IS_MISSING
              for (@$fr ? $#{$fr} + 1 : 0) .. $#{$self->{_COLUMN_NAMES}};
          @$fr == 1 && (!defined $fr->[0] || $fr->[0] eq "") and
              $self->{_FFLAGS}[0] ||= IS_MISSING;
          }
      @hr{@{$self->{_COLUMN_NAMES}}} = @$fr;
      \%hr;
  }
  
  sub getline_hr_all {
      my ( $self, $io, @args ) = @_;
  
      unless ( $self->{_COLUMN_NAMES} ) {
          croak $self->SetDiag( 3002 );
      }
  
      my @cn = @{$self->{_COLUMN_NAMES}};
  
      return [ map { my %h; @h{ @cn } = @$_; \%h } @{ $self->getline_all( $io, @args ) } ];
  }
  
  sub say {
      my ($self, $io, @f) = @_;
      my $eol = $self->eol;
      $eol eq "" and $self->eol ($\ || $/);
      # say ($fh, undef) does not propage actual undef to print ()
      my $state = $self->print ($io, @f == 1 && !defined $f[0] ? undef : @f);
      $self->eol ($eol);
      return $state;
      }
  
  sub print_hr {
      my ($self, $io, $hr) = @_;
      $self->{_COLUMN_NAMES} or croak($self->SetDiag(3009));
      ref $hr eq "HASH"      or croak($self->SetDiag(3010));
      $self->print ($io, [ map { $hr->{$_} } $self->column_names ]);
  }
  
  sub fragment {
      my ($self, $io, $spec) = @_;
  
      my $qd = qr{\s* [0-9]+ \s* }x;                # digit
      my $qs = qr{\s* (?: [0-9]+ | \* ) \s*}x;        # digit or star
      my $qr = qr{$qd (?: - $qs )?}x;                # range
      my $qc = qr{$qr (?: ; $qr )*}x;                # list
      defined $spec && $spec =~ m{^ \s*
          \x23 ? \s*                                # optional leading #
          ( row | col | cell ) \s* =
          ( $qc                                        # for row and col
          | $qd , $qd (?: - $qs , $qs)?                # for cell (ranges)
            (?: ; $qd , $qd (?: - $qs , $qs)? )*        # and cell (range) lists
          ) \s* $}xi or croak ($self->SetDiag (2013));
      my ($type, $range) = (lc $1, $2);
  
      my @h = $self->column_names ();
  
      my @c;
      if ($type eq "cell") {
          my @spec;
          my $min_row;
          my $max_row = 0;
          for (split m/\s*;\s*/ => $range) {
              my ($tlr, $tlc, $brr, $brc) = (m{
                      ^ \s* ([0-9]+     ) \s* , \s* ([0-9]+     ) \s*
                  (?: - \s* ([0-9]+ | \*) \s* , \s* ([0-9]+ | \*) \s* )?
                      $}x) or croak ($self->SetDiag (2013));
              defined $brr or ($brr, $brc) = ($tlr, $tlc);
              $tlr == 0 || $tlc == 0 ||
                  ($brr ne "*" && ($brr == 0 || $brr < $tlr)) ||
                  ($brc ne "*" && ($brc == 0 || $brc < $tlc))
                      and croak ($self->SetDiag (2013));
              $tlc--;
              $brc-- unless $brc eq "*";
              defined $min_row or $min_row = $tlr;
              $tlr < $min_row and $min_row = $tlr;
              $brr eq "*" || $brr > $max_row and
                  $max_row = $brr;
              push @spec, [ $tlr, $tlc, $brr, $brc ];
              }
          my $r = 0;
          while (my $row = $self->getline ($io)) {
              ++$r < $min_row and next;
              my %row;
              my $lc;
              foreach my $s (@spec) {
                  my ($tlr, $tlc, $brr, $brc) = @$s;
                  $r <  $tlr || ($brr ne "*" && $r > $brr) and next;
                  !defined $lc || $tlc < $lc and $lc = $tlc;
                  my $rr = $brc eq "*" ? $#$row : $brc;
                  $row{$_} = $row->[$_] for $tlc .. $rr;
                  }
              push @c, [ @row{sort { $a <=> $b } keys %row } ];
              if (@h) {
                  my %h; @h{@h} = @{$c[-1]};
                  $c[-1] = \%h;
                  }
              $max_row ne "*" && $r == $max_row and last;
              }
          return \@c;
          }
  
      # row or col
      my @r;
      my $eod = 0;
      for (split m/\s*;\s*/ => $range) {
          my ($from, $to) = m/^\s* ([0-9]+) (?: \s* - \s* ([0-9]+ | \* ))? \s* $/x
              or croak ($self->SetDiag (2013));
          $to ||= $from;
          $to eq "*" and ($to, $eod) = ($from, 1);
          # $to cannot be <= 0 due to regex and ||=
          $from <= 0 || $to < $from and croak ($self->SetDiag (2013));
          $r[$_] = 1 for $from .. $to;
          }
  
      my $r = 0;
      $type eq "col" and shift @r;
      $_ ||= 0 for @r;
      while (my $row = $self->getline ($io)) {
          $r++;
          if ($type eq "row") {
              if (($r > $#r && $eod) || $r[$r]) {
                  push @c, $row;
                  if (@h) {
                      my %h; @h{@h} = @{$c[-1]};
                      $c[-1] = \%h;
                      }
                  }
              next;
              }
          push @c, [ map { ($_ > $#r && $eod) || $r[$_] ? $row->[$_] : () } 0..$#$row ];
          if (@h) {
              my %h; @h{@h} = @{$c[-1]};
              $c[-1] = \%h;
              }
          }
  
      return \@c;
      }
  
  my $csv_usage = q{usage: my $aoa = csv (in => $file);};
  
  sub _csv_attr {
      my %attr = (@_ == 1 && ref $_[0] eq "HASH" ? %{$_[0]} : @_) or croak;
  
      $attr{binary} = 1;
  
      my $enc = delete $attr{enc} || delete $attr{encoding} || "";
      $enc eq "auto" and ($attr{detect_bom}, $enc) = (1, "");
      my $stack = $enc =~ s/(:\w.*)// ? $1 : "";
      $enc =~ m/^[-\w.]+$/ and $enc = ":encoding($enc)";
      $enc .= $stack;
  
      my $fh;
      my $sink = 0;
      my $cls  = 0;  # If I open a file, I have to close it
      my $in   = delete $attr{in}  || delete $attr{file} or croak $csv_usage;
      my $out  = exists $attr{out} && !$attr{out} ? \"skip"
          : delete $attr{out} || delete $attr{file};
  
      ref $in eq "CODE" || ref $in eq "ARRAY" and $out ||= \*STDOUT;
  
      $in && $out && !ref $in && !ref $out and croak join "\n" =>
         qq{Cannot use a string for both in and out. Instead use:},
         qq{ csv (in => csv (in => "$in"), out => "$out");\n};
  
      if ($out) {
          if (ref $out and ("ARRAY" eq ref $out or "HASH" eq ref $out)) {
              delete $attr{out};
              $sink = 1;
              }
          elsif ((ref $out and "SCALAR" ne ref $out) or "GLOB" eq ref \$out) {
              $fh = $out;
              }
          elsif (ref $out and "SCALAR" eq ref $out and defined $$out and $$out eq "skip") {
              delete $attr{out};
              $sink = 1;
              }
          else {
              open $fh, ">", $out or croak "$out: $!";
              $cls = 1;
              }
          if ($fh) {
              if ($enc) {
                  binmode $fh, $enc;
                  my $fn = fileno $fh; # This is a workaround for a bug in PerlIO::via::gzip
              }
              unless (defined $attr{eol}) {
                  my @layers = eval { PerlIO::get_layers ($fh) };
                  $attr{eol} = (grep m/crlf/ => @layers) ? "\n" : "\r\n";
                  }
              }
          }
  
      if (   ref $in eq "CODE" or ref $in eq "ARRAY") {
          # All done
          }
      elsif (ref $in eq "SCALAR") {
          # Strings with code points over 0xFF may not be mapped into in-memory file handles
          # "<$enc" does not change that :(
          open $fh, "<", $in or croak "Cannot open from SCALAR using PerlIO";
          $cls = 1;
          }
      elsif (ref $in or "GLOB" eq ref \$in) {
          if (!ref $in && $] < 5.008005) {
              $fh = \*$in; # uncoverable statement ancient perl version required
              }
          else {
              $fh = $in;
              }
          }
      else {
          open $fh, "<$enc", $in or croak "$in: $!";
          $cls = 1;
          }
      $fh || $sink or croak qq{No valid source passed. "in" is required};
  
      my $hdrs = delete $attr{headers};
      my $frag = delete $attr{fragment};
      my $key  = delete $attr{key};
      my $val  = delete $attr{value};
      my $kh   = delete $attr{keep_headers}      ||
            delete $attr{keep_column_names}      ||
            delete $attr{kh};
  
      my $cbai = delete $attr{callbacks}{after_in}    ||
                 delete $attr{after_in}               ||
                 delete $attr{callbacks}{after_parse} ||
                 delete $attr{after_parse};
      my $cbbo = delete $attr{callbacks}{before_out}  ||
                 delete $attr{before_out};
      my $cboi = delete $attr{callbacks}{on_in}       ||
                 delete $attr{on_in};
  
      my $hd_s = delete $attr{sep_set}                ||
                 delete $attr{seps};
      my $hd_b = delete $attr{detect_bom}             ||
                 delete $attr{bom};
      my $hd_m = delete $attr{munge}                  ||
                 delete $attr{munge_column_names};
      my $hd_c = delete $attr{set_column_names};
  
      for ([ quo    => "quote"                ],
           [ esc    => "escape"                ],
           [ escape => "escape_char"        ],
           ) {
          my ($f, $t) = @$_;
          exists $attr{$f} and !exists $attr{$t} and $attr{$t} = delete $attr{$f};
          }
  
      my $fltr = delete $attr{filter};
      my %fltr = (
          not_blank => sub { @{$_[1]} > 1 or defined $_[1][0] && $_[1][0] ne "" },
          not_empty => sub { grep { defined && $_ ne "" } @{$_[1]} },
          filled    => sub { grep { defined && m/\S/    } @{$_[1]} },
          );
      defined $fltr && !ref $fltr && exists $fltr{$fltr} and
          $fltr = { 0 => $fltr{$fltr} };
      ref $fltr eq "CODE" and $fltr = { 0 => $fltr };
      ref $fltr eq "HASH" or $fltr = undef;
  
      my $form = delete $attr{formula};
  
      defined $attr{auto_diag}   or $attr{auto_diag}   = 1;
      defined $attr{escape_null} or $attr{escape_null} = 0;
      my $csv = delete $attr{csv} || Text::CSV_PP->new (\%attr)
          or croak $last_new_error;
      defined $form and $csv->formula ($form);
  
      $kh && !ref $kh && $kh =~ m/^(?:1|yes|true|internal|auto)$/i and
          $kh = \@internal_kh;
  
      return {
          csv  => $csv,
          attr => { %attr },
          fh   => $fh,
          cls  => $cls,
          in   => $in,
          sink => $sink,
          out  => $out,
          enc  => $enc,
          hdrs => $hdrs,
          key  => $key,
          val  => $val,
          kh   => $kh,
          frag => $frag,
          fltr => $fltr,
          cbai => $cbai,
          cbbo => $cbbo,
          cboi => $cboi,
          hd_s => $hd_s,
          hd_b => $hd_b,
          hd_m => $hd_m,
          hd_c => $hd_c,
          };
      }
  
  sub csv {
      @_ && (ref $_[0] eq __PACKAGE__ or ref $_[0] eq 'Text::CSV') and splice @_, 0, 0, "csv";
      @_ or croak $csv_usage;
  
      my $c = _csv_attr (@_);
  
      my ($csv, $in, $fh, $hdrs) = @{$c}{qw( csv in fh hdrs )};
      my %hdr;
      if (ref $hdrs eq "HASH") {
          %hdr  = %$hdrs;
          $hdrs = "auto";
          }
  
      if ($c->{out} && !$c->{sink}) {
         !$hdrs && ref $c->{'kh'} && $c->{'kh'} == \@internal_kh and
              $hdrs = $c->{'kh'};
  
          if (ref $in eq "CODE") {
              my $hdr = 1;
              while (my $row = $in->($csv)) {
                  if (ref $row eq "ARRAY") {
                      $csv->print ($fh, $row);
                      next;
                      }
                  if (ref $row eq "HASH") {
                      if ($hdr) {
                          $hdrs ||= [ map { $hdr{$_} || $_ } keys %$row ];
                          $csv->print ($fh, $hdrs);
                          $hdr = 0;
                          }
                      $csv->print ($fh, [ @{$row}{@$hdrs} ]);
                      }
                  }
              }
          elsif (@{$in} == 0 or ref $in->[0] eq "ARRAY") { # aoa
              ref $hdrs and $csv->print ($fh, $hdrs);
              for (@{$in}) {
                  $c->{cboi} and $c->{cboi}->($csv, $_);
                  $c->{cbbo} and $c->{cbbo}->($csv, $_);
                  $csv->print ($fh, $_);
                  }
              }
          else { # aoh
              my @hdrs = ref $hdrs ? @{$hdrs} : keys %{$in->[0]};
              defined $hdrs or $hdrs = "auto";
              ref $hdrs || $hdrs eq "auto" and @hdrs and
                  $csv->print ($fh, [ map { $hdr{$_} || $_ } @hdrs ]);
              for (@{$in}) {
                  local %_;
                  *_ = $_;
                  $c->{cboi} and $c->{cboi}->($csv, $_);
                  $c->{cbbo} and $c->{cbbo}->($csv, $_);
                  $csv->print ($fh, [ @{$_}{@hdrs} ]);
                  }
              }
  
          $c->{cls} and close $fh;
          return 1;
          }
  
      my @row1;
      if (defined $c->{hd_s} || defined $c->{hd_b} || defined $c->{hd_m} || defined $c->{hd_c}) {
          my %harg;
          !defined $c->{'hd_s'} &&  $c->{'attr'}{'sep_char'} and
                   $c->{'hd_s'} = [ $c->{'attr'}{'sep_char'} ];
          !defined $c->{'hd_s'} &&  $c->{'attr'}{'sep'} and
                   $c->{'hd_s'} = [ $c->{'attr'}{'sep'} ];
          defined  $c->{'hd_s'} and $harg{'sep_set'}            = $c->{'hd_s'};
          defined  $c->{'hd_b'} and $harg{'detect_bom'}         = $c->{'hd_b'};
          defined  $c->{'hd_m'} and $harg{'munge_column_names'} = $hdrs ? "none" : $c->{'hd_m'};
          defined  $c->{'hd_c'} and $harg{'set_column_names'}   = $hdrs ? 0      : $c->{'hd_c'};
          @row1 = $csv->header ($fh, \%harg);
          my @hdr = $csv->column_names;
          @hdr and $hdrs ||= \@hdr;
          }
  
      if ($c->{kh}) {
          @internal_kh = ();
          ref $c->{kh} eq "ARRAY" or croak ($csv->SetDiag (1501));
          $hdrs ||= "auto";
          }
  
      my $key = $c->{key};
      if ($key) {
         !ref $key or ref $key eq "ARRAY" && @$key > 1 or croak ($csv->SetDiag (1501));
          $hdrs ||= "auto";
          }
      my $val = $c->{val};
      if ($val) {
         $key                                          or croak ($csv->SetDiag (1502));
         !ref $val or ref $val eq "ARRAY" && @$val > 0 or croak ($csv->SetDiag (1503));
         }
  
      $c->{fltr} && grep m/\D/ => keys %{$c->{fltr}} and $hdrs ||= "auto";
      if (defined $hdrs) {
          if (!ref $hdrs or ref $hdrs eq "CODE") {
              my $h = $c->{'hd_b'}
                  ? [ $csv->column_names () ]
                  :   $csv->getline ($fh);
              my $has_h = $h && @$h;
  
              if (ref $hdrs) {
                  $has_h or return;
                  my $cr = $hdrs;
                  $hdrs  = [ map {  $cr->($hdr{$_} || $_) } @{$h} ];
                  }
              elsif ($hdrs eq "skip") {
                  # discard;
                  }
              elsif ($hdrs eq "auto") {
                  $has_h or return;
                  $hdrs = [ map {      $hdr{$_} || $_ } @$h ];
                  }
              elsif ($hdrs eq "lc") {
                  $has_h or return;
                  $hdrs = [ map { lc ($hdr{$_} || $_) } @$h ];
                  }
              elsif ($hdrs eq "uc") {
                  $has_h or return;
                  $hdrs = [ map { uc ($hdr{$_} || $_) } @$h ];
                  }
              }
          $c->{kh} and $hdrs and @{$c->{kh}} = @$hdrs;
          }
  
      if ($c->{fltr}) {
          my %f = %{$c->{fltr}};
          # convert headers to index
          my @hdr;
          if (ref $hdrs) {
              @hdr = @{$hdrs};
              for (0 .. $#hdr) {
                  exists $f{$hdr[$_]} and $f{$_ + 1} = delete $f{$hdr[$_]};
                  }
              }
          $csv->callbacks (after_parse => sub {
              my ($CSV, $ROW) = @_; # lexical sub-variables in caps
              foreach my $FLD (sort keys %f) {
                  local $_ = $ROW->[$FLD - 1];
                  local %_;
                  @hdr and @_{@hdr} = @$ROW;
                  $f{$FLD}->($CSV, $ROW) or return \"skip";
                  $ROW->[$FLD - 1] = $_;
                  }
              });
          }
  
      my $frag = $c->{frag};
      my $ref = ref $hdrs
          ? # aoh
            do {
              my @h = $csv->column_names ($hdrs);
              my %h; $h{$_}++ for @h;
              exists $h{''} and croak ($csv->SetDiag (1012));
              unless (keys %h == @h) {
                  croak ($csv->_SetDiagInfo (1013, join ", " =>
                      map { "$_ ($h{$_})" } grep { $h{$_} > 1 } keys %h));
                  }
              $frag ? $csv->fragment ($fh, $frag) :
              $key  ? do {
                          my ($k, $j, @f) = ref $key ? (undef, @$key) : ($key);
                          if (my @mk = grep { !exists $h{$_} } grep { defined } $k, @f) {
                              croak ($csv->_SetDiagInfo (4001, join ", " => @mk));
                              }
                          +{ map {
                              my $r = $_;
                              my $K = defined $k ? $r->{$k} : join $j => @{$r}{@f};
                              ( $K => (
                              $val
                                  ? ref $val
                                      ? { map { $_ => $r->{$_} } @$val }
                                      : $r->{$val}
                                  : $r ));
                              } @{$csv->getline_hr_all ($fh)} }
                          }
                    : $csv->getline_hr_all ($fh);
              }
          : # aoa
              $frag ? $csv->fragment ($fh, $frag)
                    : $csv->getline_all ($fh);
      if ($ref) {
          @row1 && !$c->{hd_c} && !ref $hdrs and unshift @$ref, \@row1;
          }
      else {
          Text::CSV_PP->auto_diag;
          }
      $c->{cls} and close $fh;
      if ($ref and $c->{cbai} || $c->{cboi}) {
          # Default is ARRAYref, but with key =>, you'll get a hashref
          foreach my $r (ref $ref eq "ARRAY" ? @{$ref} : values %{$ref}) {
              local %_;
              ref $r eq "HASH" and *_ = $r;
              $c->{cbai} and $c->{cbai}->($csv, $r);
              $c->{cboi} and $c->{cboi}->($csv, $r);
              }
          }
  
      if ($c->{sink}) {
          my $ro = ref $c->{out} or return;
  
          $ro eq "SCALAR" && ${$c->{out}} eq "skip" and
              return;
  
          $ro eq ref $ref or
              croak ($csv->_SetDiagInfo (5001, "Output type mismatch"));
  
          if ($ro eq "ARRAY") {
              if (@{$c->{out}} and @$ref and ref $c->{out}[0] eq ref $ref->[0]) {
                  push @{$c->{out}} => @$ref;
                  return $c->{out};
              }
              croak ($csv->_SetDiagInfo (5001, "Output type mismatch"));
          }
  
          if ($ro eq "HASH") {
              @{$c->{out}}{keys %{$ref}} = values %{$ref};
              return $c->{out};
          }
  
          croak ($csv->_SetDiagInfo (5002, "Unsupported output type"));
      }
  
      defined wantarray or
          return csv (
              in => $ref,
              headers => $hdrs,
              %{$c->{attr}},
          );
  
      return $ref;
      }
  
  # The end of the common pure perl part.
  
  ################################################################################
  #
  # The following are methods implemented in XS in Text::CSV_XS or
  # helper methods for Text::CSV_PP only
  #
  ################################################################################
  
  sub _setup_ctx {
      my $self = shift;
  
      $last_error = undef;
  
      my $ctx;
      if ($self->{_CACHE}) {
          %$ctx = %{$self->{_CACHE}};
      } else {
          $ctx->{sep} = ',';
          if (defined $self->{sep_char}) {
              $ctx->{sep} = $self->{sep_char};
          }
          if (defined $self->{sep} and $self->{sep} ne '') {
              use bytes;
              $ctx->{sep} = $self->{sep};
              my $sep_len = length($ctx->{sep});
              $ctx->{sep_len} = $sep_len if $sep_len > 1;
          }
  
          $ctx->{quo} = '"';
          if (exists $self->{quote_char}) {
              my $quote_char = $self->{quote_char};
              if (defined $quote_char and length $quote_char) {
                  $ctx->{quo} = $quote_char;
              } else {
                  $ctx->{quo} = "\0";
              }
          }
          if (defined $self->{quote} and $self->{quote} ne '') {
              use bytes;
              $ctx->{quo} = $self->{quote};
              my $quote_len = length($ctx->{quo});
              $ctx->{quo_len} = $quote_len if $quote_len > 1;
          }
  
          $ctx->{escape_char} = '"';
          if (exists $self->{escape_char}) {
              my $escape_char = $self->{escape_char};
              if (defined $escape_char and length $escape_char) {
                  $ctx->{escape_char} = $escape_char;
              } else {
                  $ctx->{escape_char} = "\0";
              }
          }
  
          if (defined $self->{eol}) {
              my $eol = $self->{eol};
              my $eol_len = length($eol);
              $ctx->{eol} = $eol;
              $ctx->{eol_len} = $eol_len;
              if ($eol_len == 1 and $eol eq "\015") {
                  $ctx->{eol_is_cr} = 1;
              }
          }
  
          $ctx->{undef_flg} = 0;
          if (defined $self->{undef_str}) {
              $ctx->{undef_str} = $self->{undef_str};
              $ctx->{undef_flg} = 3 if utf8::is_utf8($self->{undef_str});
          } else {
              $ctx->{undef_str} = undef;
          }
          if (defined $self->{comment_str}) {
              $ctx->{comment_str} = $self->{comment_str};
          }
  
          if (defined $self->{_types}) {
              $ctx->{types} = $self->{_types};
              $ctx->{types_len} = length($ctx->{types});
          }
  
          if (defined $self->{_is_bound}) {
              $ctx->{is_bound} = $self->{_is_bound};
          }
  
          if (defined $self->{callbacks}) {
              my $cb = $self->{callbacks};
              $ctx->{has_hooks} = 0;
              if (defined $cb->{after_parse} and ref $cb->{after_parse} eq 'CODE') {
                  $ctx->{has_hooks} |= HOOK_AFTER_PARSE;
              }
              if (defined $cb->{before_print} and ref $cb->{before_print} eq 'CODE') {
                  $ctx->{has_hooks} |= HOOK_BEFORE_PRINT;
              }
          }
  
          for (qw/
              binary decode_utf8 always_quote strict quote_empty
              allow_loose_quotes allow_loose_escapes
              allow_unquoted_escape allow_whitespace blank_is_undef
              empty_is_undef verbatim auto_diag diag_verbose
              keep_meta_info formula skip_empty_rows
          /) {
              $ctx->{$_} = defined $self->{$_} ? $self->{$_} : 0;
          }
          for (qw/quote_space escape_null quote_binary/) {
              $ctx->{$_} = defined $self->{$_} ? $self->{$_} : 1;
          }
          if ($ctx->{escape_char} eq "\0") {
              $ctx->{escape_null} = 0;
          }
  
          # FIXME: readonly
          %{$self->{_CACHE}} = %$ctx;
      }
  
      $ctx->{utf8} = 0;
      $ctx->{size} = 0;
      $ctx->{used} = 0;
  
      if ($ctx->{is_bound}) {
          my $bound = $self->{_BOUND_COLUMNS};
          if ($bound and ref $bound eq 'ARRAY') {
              $ctx->{bound} = $bound;
          } else {
              $ctx->{is_bound} = 0;
          }
      }
  
      $ctx->{eol_pos} = -1;
      $ctx->{eolx} = $ctx->{eol_len}
          ? $ctx->{verbatim} || $ctx->{eol_len} >= 2
              ? 1
              : $ctx->{eol} =~ /\A[\015\012]/ ? 0 : 1
          : 0;
  
      if ($ctx->{sep_len} and $ctx->{sep_len} > 1 and _is_valid_utf8($ctx->{sep})) {
          $ctx->{utf8} = 1;
      }
      if ($ctx->{quo_len} and $ctx->{quo_len} > 1 and _is_valid_utf8($ctx->{quo})) {
          $ctx->{utf8} = 1;
      }
  
      $ctx;
  }
  
  sub _cache_set {
      my ($self, $idx, $value) = @_;
      return unless exists $self->{_CACHE};
      my $cache = $self->{_CACHE};
  
      my $key = $_reverse_cache_id{$idx};
      if (!defined $key) {
          warn (sprintf "Unknown cache index %d ignored\n", $idx);
      } elsif ($key eq 'sep_char') {
          $cache->{sep} = $value;
          $cache->{sep_len} = 0;
      }
      elsif ($key eq 'quote_char') {
          $cache->{quo} = $value;
          $cache->{quo_len} = 0;
      }
      elsif ($key eq '_has_ahead') {
          $cache->{has_ahead} = $value;
      }
      elsif ($key eq '_has_hooks') {
          $cache->{has_hooks} = $value;
      }
      elsif ($key eq '_is_bound') {
          $cache->{is_bound} = $value;
      }
      elsif ($key eq 'sep') {
          use bytes;
          my $len = bytes::length($value);
          $cache->{sep} = $value if $len;
          $cache->{sep_len} = $len == 1 ? 0 : $len;
      }
      elsif ($key eq 'quote') {
          use bytes;
          my $len = bytes::length($value);
          $cache->{quo} = $value if $len;
          $cache->{quo_len} = $len == 1 ? 0 : $len;
      }
      elsif ($key eq 'eol') {
          if (defined($value)) {
              $cache->{eol} = $value;
              $cache->{eol_len} = length($value);
          }
          $cache->{eol_is_cr} = $value eq "\015" ? 1 : 0;
      }
      elsif ($key eq 'undef_str') {
          if (defined $value) {
              $cache->{undef_str} = $value;
              $cache->{undef_flg} = 3 if utf8::is_utf8($value);
          } else {
              $cache->{undef_str} = undef;
              $cache->{undef_flg} = 0;
          }
      }
      else {
          $cache->{$key} = $value;
      }
      return 1;
  }
  
  sub _cache_diag {
      my $self = shift;
      unless (exists $self->{_CACHE}) {
          warn ("CACHE: invalid\n");
          return;
      }
  
      my $cache = $self->{_CACHE};
      warn ("CACHE:\n");
      $self->__cache_show_char(quote_char => $cache->{quo});
      $self->__cache_show_char(escape_char => $cache->{escape_char});
      $self->__cache_show_char(sep_char => $cache->{sep});
      for (qw/
          binary decode_utf8 allow_loose_escapes allow_loose_quotes allow_unquoted_escape
          allow_whitespace always_quote quote_empty quote_space
          escape_null quote_binary auto_diag diag_verbose formula strict skip_empty_rows
          has_error_input blank_is_undef empty_is_undef has_ahead
          keep_meta_info verbatim has_hooks eol_is_cr eol_len
      /) {
          $self->__cache_show_byte($_ => $cache->{$_});
      }
      $self->__cache_show_str(eol => $cache->{eol_len}, $cache->{eol});
      $self->__cache_show_byte(sep_len => $cache->{sep_len});
      if ($cache->{sep_len} and $cache->{sep_len} > 1) {
          $self->__cache_show_str(sep => $cache->{sep_len}, $cache->{sep});
      }
      $self->__cache_show_byte(quo_len => $cache->{quo_len});
      if ($cache->{quo_len} and $cache->{quo_len} > 1) {
          $self->__cache_show_str(quote => $cache->{quo_len}, $cache->{quo});
      }
      if ($cache->{types_len}) {
          $self->__cache_show_str(types => $cache->{types_len}, $cache->{types});
      } else {
          $self->__cache_show_str(types => 0, "");
      }
      if ($cache->{bptr}) {
          $self->__cache_show_str(bptr => length($cache->{bptr}), $cache->{bptr});
      }
      if ($cache->{tmp}) {
          $self->__cache_show_str(tmp => length($cache->{tmp}), $cache->{tmp});
      }
  }
  
  sub __cache_show_byte {
      my ($self, $key, $value) = @_;
      warn (sprintf "  %-21s %02x:%3d\n", $key, defined $value ? ord($value) : 0, defined $value ? $value : 0);
  }
  
  sub __cache_show_char {
      my ($self, $key, $value) = @_;
      my $v = $value;
      if (defined $value) {
          my @b = unpack "U0C*", $value;
          $v = pack "U*", $b[0];
      }
      warn (sprintf "  %-21s %02x:%s\n", $key, defined $v ? ord($v) : 0, $self->__pretty_str($v, 1));
  }
  
  sub __cache_show_str {
      my ($self, $key, $len, $value) = @_;
      warn (sprintf "  %-21s %02d:%s\n", $key, $len, $self->__pretty_str($value, $len));
  }
  
  sub __pretty_str { # FIXME
      my ($self, $str, $len) = @_;
      return '' unless defined $str;
      $str = substr($str, 0, $len);
      $str =~ s/"/\\"/g;
      $str =~ s/([^\x09\x20-\x7e])/sprintf '\\x{%x}', ord($1)/eg;
      qq{"$str"};
  }
  
  sub _hook {
      my ($self, $name, $fields) = @_;
      return 0 unless $self->{callbacks};
  
      my $cb = $self->{callbacks}{$name};
      return 0 unless $cb && ref $cb eq 'CODE';
  
      my (@res) = $cb->($self, $fields);
      if (@res) {
          return 0 if ref $res[0] eq 'SCALAR' and ${$res[0]} eq "skip";
      }
      scalar @res;
  }
  
  ################################################################################
  # methods for combine
  ################################################################################
  
  sub __combine {
      my ($self, $dst, $fields, $useIO) = @_;
  
      my $ctx = $self->_setup_ctx;
  
      my ($binary, $quot, $sep, $esc, $quote_space) = @{$ctx}{qw/binary quo sep escape_char quote_space/};
  
      if(!defined $quot or $quot eq "\0"){ $quot = ''; }
  
      my $re_esc;
      if ($esc ne '' and $esc ne "\0") {
        if ($quot ne '') {
          $re_esc = $self->{_re_comb_escape}->{$quot}->{$esc} ||= qr/(\Q$quot\E|\Q$esc\E)/;
        } else {
          $re_esc = $self->{_re_comb_escape}->{$quot}->{$esc} ||= qr/(\Q$esc\E)/;
        }
      }
  
      my $bound = 0;
      my $n = @$fields - 1;
      if ($n < 0 and $ctx->{is_bound}) {
          $n = $ctx->{is_bound} - 1;
          $bound = 1;
      }
  
      my $check_meta = ($ctx->{keep_meta_info} >= 10 and @{$self->{_FFLAGS} || []} >= $n) ? 1 : 0;
  
      my $must_be_quoted;
      my @results;
      for(my $i = 0; $i <= $n; $i++) {
          my $v_ref;
          if ($bound) {
              $v_ref = $self->__bound_field($ctx, $i, 1);
          } else {
              if (@$fields > $i) {
                  $v_ref = \($fields->[$i]);
              }
          }
          next unless $v_ref;
  
          my $value = $$v_ref;
  
          if (!defined $value) {
              if ($ctx->{undef_str}) {
                  if ($ctx->{undef_flg}) {
                      $ctx->{utf8} = 1;
                      $ctx->{binary} = 1;
                  }
                  push @results, $ctx->{undef_str};
              } else {
                  push @results, '';
              }
              next;
          }
  
          if ( substr($value, 0, 1) eq '=' && $ctx->{formula} ) {
              $value = $self->_formula($ctx, $value, $i);
              if (!defined $value) {
                  push @results, '';
                  next;
              }
          }
  
          $must_be_quoted = $ctx->{always_quote} ? 1 : 0;
          if ($value eq '') {
              $must_be_quoted++ if $ctx->{quote_empty} or ($check_meta && $self->is_quoted($i));
          }
          else {
  
              if (utf8::is_utf8 $value) {
                  $ctx->{utf8} = 1;
                  $ctx->{binary} = 1;
              }
  
              $must_be_quoted++ if $check_meta && $self->is_quoted($i);
  
              if (!$must_be_quoted and $quot ne '') {
                  use bytes;
                  $must_be_quoted++ if
                      ($value =~ /\Q$quot\E/) ||
                      ($sep ne '' and $sep ne "\0" and $value =~ /\Q$sep\E/) ||
                      ($esc ne '' and $esc ne "\0" and $value =~ /\Q$esc\E/) ||
                      ($ctx->{quote_binary} && $value =~ /[\x00-\x1f\x7f-\xa0]/) ||
                      ($ctx->{quote_space} && $value =~ /[\x09\x20]/);
              }
  
              if (!$ctx->{binary} and $value =~ /[^\x09\x20-\x7E]/) {
                  # an argument contained an invalid character...
                  $self->{_ERROR_INPUT} = $value;
                  $self->SetDiag(2110);
                  return 0;
              }
  
              if ($re_esc) {
                  $value =~ s/($re_esc)/$esc$1/g;
              }
              if ($ctx->{escape_null}) {
                  $value =~ s/\0/${esc}0/g;
              }
          }
  
          if ($must_be_quoted) {
              $value = $quot . $value . $quot;
          }
          push @results, $value;
      }
  
      $$dst = join($sep, @results) . ( defined $ctx->{eol} ? $ctx->{eol} : '' );
  
      return 1;
  }
  
  sub _formula {
      my ($self, $ctx, $value, $i) = @_;
  
      my $fa = $ctx->{formula} or return;
      if ($fa == 1) { die "Formulas are forbidden\n" }
      if ($fa == 2) { die "Formulas are forbidden\n" } # XS croak behaves like PP's "die"
  
      if ($fa == 3) {
          my $rec = '';
          if ($ctx->{recno}) {
              $rec = sprintf " in record %lu", $ctx->{recno} + 1;
          }
          my $field = '';
          my $column_names = $self->{_COLUMN_NAMES};
          if (ref $column_names eq 'ARRAY' and @$column_names >= $i - 1) {
              my $column_name = $column_names->[$i - 1];
              $field = sprintf " (column: '%.100s')", $column_name if defined $column_name;
          }
          warn sprintf("Field %d%s%s contains formula '%s'\n", $i, $field, $rec, $value);
          return $value;
      }
  
      if ($fa == 4) {
          return '';
      }
      if ($fa == 5) {
          return undef;
      }
  
      if ($fa == 6) {
          if (ref $self->{_FORMULA_CB} eq 'CODE') {
              local $_ = $value;
              return $self->{_FORMULA_CB}->();
          }
      }
      return;
  }
  
  sub print {
      my ($self, $io, $fields) = @_;
  
      require IO::Handle;
  
      if (!defined $fields) {
          $fields = [];
      } elsif(ref($fields) ne 'ARRAY'){
          Carp::croak("Expected fields to be an array ref");
      }
  
      $self->_hook(before_print => $fields);
  
      my $str = "";
      $self->__combine(\$str, $fields, 1) or return '';
  
      local $\ = '';
  
      $io->print( $str ) or $self->_set_error_diag(2200);
  }
  
  ################################################################################
  # methods for parse
  ################################################################################
  
  
  sub __parse { # cx_xsParse
      my ($self, $fields, $fflags, $src, $useIO) = @_;
  
      my $ctx = $self->_setup_ctx;
  
      my $state = $self->___parse($ctx, $fields, $fflags, $src, $useIO);
      if ($state and ($ctx->{has_hooks} || 0) & HOOK_AFTER_PARSE) {
          $self->_hook(after_parse => $fields);
      }
      return $state || !$last_error;
  }
  
  sub ___parse { # cx_c_xsParse
      my ($self, $ctx, $fields, $fflags, $src, $useIO) = @_;
  
      local $/ = $ctx->{eol} if $ctx->{eolx} or $ctx->{eol_is_cr};
  
      if ($ctx->{useIO} = $useIO) {
          require IO::Handle;
  
          $ctx->{tmp} = undef;
          if ($ctx->{has_ahead} and defined $self->{_AHEAD}) {
              $ctx->{tmp} = $self->{_AHEAD};
              $ctx->{size} = length $ctx->{tmp};
              $ctx->{used} = 0;
          }
      } else {
          $ctx->{tmp} = $src;
          $ctx->{size} = length $src;
          $ctx->{used} = 0;
          $ctx->{utf8} = utf8::is_utf8($src);
      }
      if ($ctx->{has_error_input}) {
          $self->{_ERROR_INPUT} = undef;
          $ctx->{has_error_input} = 0;
      }
  
      my $result = $self->____parse($ctx, $src, $fields, $fflags);
      $self->{_RECNO} = ++($ctx->{recno});
      $self->{_EOF} = '';
  
      if ($ctx->{strict}) {
          $ctx->{strict_n} ||= $ctx->{fld_idx};
          if ($ctx->{strict_n} != $ctx->{fld_idx}) {
              unless ($ctx->{useIO} & useIO_EOF) {
                  $self->__parse_error($ctx, 2014, $ctx->{used});
              }
              if ($last_error) {
                  $result = undef;
              }
          }
      }
  
      if ($ctx->{useIO}) {
          if (defined $ctx->{tmp} and $ctx->{used} < $ctx->{size} and $ctx->{has_ahead}) {
              $self->{_AHEAD} = substr($ctx->{tmp}, $ctx->{used}, $ctx->{size} - $ctx->{used});
          } else {
              $ctx->{has_ahead} = 0;
              if ($ctx->{useIO} & useIO_EOF) {
                  $self->{_EOF} = 1;
              }
          }
          %{$self->{_CACHE}} = %$ctx;
  
          if ($fflags) {
              if ($ctx->{keep_meta_info}) {
                  $self->{_FFLAGS} = $fflags;
              } else {
                  undef $fflags;
              }
          }
      } else {
          %{$self->{_CACHE}} = %$ctx;
      }
  
      if ($result and $ctx->{types}) {
          my $len = @$fields;
          for(my $i = 0; $i <= $len && $i <= $ctx->{types_len}; $i++) {
              my $value = $fields->[$i];
              next unless defined $value;
              my $type = ord(substr($ctx->{types}, $i, 1));
              if ($type == IV) {
                  $fields->[$i] = int($value);
              } elsif ($type == NV) {
                  $fields->[$i] = $value + 0.0;
              }
          }
      }
  
      $result;
  }
  
  sub ____parse { # cx_Parse
      my ($self, $ctx, $src, $fields, $fflags) = @_;
  
      my ($quot, $sep, $esc, $eol) = @{$ctx}{qw/quo sep escape_char eol/};
  
      utf8::encode($sep)  if !$ctx->{utf8} and $ctx->{sep_len};
      utf8::encode($quot) if !$ctx->{utf8} and $ctx->{quo_len};
      utf8::encode($eol)  if !$ctx->{utf8} and $ctx->{eol_len};
  
      my $seenSomething =  0;
      my $spl = -1;
      my $waitingForField = 1;
      my ($value, $v_ref);
      $ctx->{fld_idx} = my $fnum = 0;
      $ctx->{flag} = 0;
  
      my $re_str = join '|', map({$_ eq "\0" ? '[\\0]' : quotemeta($_)} sort {length $b <=> length $a} grep {defined $_ and $_ ne ''} $sep, $quot, $esc, $eol), "\015", "\012", "\x09", " ";
      $ctx->{_re} = qr/$re_str/;
      my $re = qr/$re_str|[^\x09\x20-\x7E]|$/;
  
  LOOP:
      while($self->__get_from_src($ctx, $src)) {
          while($ctx->{tmp} =~ /\G(.*?)($re)/gs) {
              my ($hit, $c) = ($1, $2);
              $ctx->{used} = pos($ctx->{tmp});
              if (!$waitingForField and $c eq '' and $hit ne '' and $ctx->{useIO} and !($ctx->{useIO} & useIO_EOF)) {
                  $self->{_AHEAD} = $hit;
                  $ctx->{has_ahead} = 1;
                  $ctx->{has_leftover} = 1;
                  last;
              }
              last if $seenSomething and $hit eq '' and $c eq ''; # EOF
  
              # new field
              if (!$v_ref) {
                  if ($ctx->{is_bound}) {
                      $v_ref = $self->__bound_field($ctx, $fnum, 0);
                  } else {
                      $value = '';
                      $v_ref = \$value;
                  }
                  $fnum++;
                  return unless $v_ref;
                  $ctx->{flag} = 0;    
                  $ctx->{fld_idx}++;
              }
  
              $seenSomething = 1;
              $spl++;
  
              if (defined $hit and $hit ne '') {
                  if ($waitingForField) {
                      if (!$spl && $ctx->{comment_str} && $ctx->{tmp} =~ /\A\Q$ctx->{comment_str}/) {
                          $ctx->{used} = $ctx->{size};
                          $ctx->{fld_idx} = 0;
                          $seenSomething = 0;
                          next LOOP;
                      }
                      $waitingForField = 0;
                  }
                  if ($hit =~ /[^\x09\x20-\x7E]/) {
                      $ctx->{flag} |= IS_BINARY;
                  }
                  $$v_ref .= $hit;
              }
  
  RESTART:
              if (defined $c and defined $sep and $c eq $sep) {
                  if ($waitingForField) {
                      # ,1,"foo, 3",,bar,
                      # ^           ^
                      if ($ctx->{blank_is_undef} or $ctx->{empty_is_undef}) {
                          $$v_ref = undef;
                      } else {
                          $$v_ref = "";
                      }
                      unless ($ctx->{is_bound}) {
                          push @$fields, $$v_ref;
                      }
                      $v_ref = undef;
                      if ($ctx->{keep_meta_info} and $fflags) {
                          push @$fflags, $ctx->{flag};
                      }
                  } elsif ($ctx->{flag} & IS_QUOTED) {
                      # ,1,"foo, 3",,bar,
                      #        ^
                      $$v_ref .= $c;
                  } else {
                      # ,1,"foo, 3",,bar,
                      #   ^        ^    ^
                      $self->__push_value($ctx, $v_ref, $fields, $fflags, $ctx->{flag}, $fnum);
                      $v_ref = undef;
                      $waitingForField = 1;
                  }
              }
              elsif (defined $c and defined $quot and $quot ne "\0" and $c eq $quot) {
                  if ($waitingForField) {
                      # ,1,"foo, 3",,bar,\r\n
                      #    ^
                      $ctx->{flag} |= IS_QUOTED;
                      $waitingForField = 0;
                      next;
                  }
                  if ($ctx->{flag} & IS_QUOTED) {
                      # ,1,"foo, 3",,bar,\r\n
                      #           ^
                      my $quoesc = 0;
                      my $c2 = $self->__get($ctx, $src);
  
                      if ($ctx->{allow_whitespace}) {
                          # , 1 , "foo, 3" , , bar , \r\n
                          #               ^
                          while($self->__is_whitespace($ctx, $c2)) {
                              if ($ctx->{allow_loose_quotes} and !(defined $esc and $c2 eq $esc)) {
                                  $$v_ref .= $c;
                                  $c = $c2;
                              }
                              $c2 = $self->__get($ctx, $src);
                          }
                      }
  
                      if (!defined $c2) { # EOF
                          # ,1,"foo, 3"
                          #            ^
                          $self->__push_value($ctx, $v_ref, $fields, $fflags, $ctx->{flag}, $fnum);
                          return 1;
                      }
  
                      if (defined $c2 and defined $sep and $c2 eq $sep) {
                          # ,1,"foo, 3",,bar,\r\n
                          #            ^
                          $self->__push_value($ctx, $v_ref, $fields, $fflags, $ctx->{flag}, $fnum);
                          $v_ref = undef;
                          $waitingForField = 1;
                          next;
                      }
                      if (defined $c2 and ($c2 eq "\012" or (defined $eol and $c2 eq $eol))) { # FIXME: EOLX
                          # ,1,"foo, 3",,"bar"\n
                          #                   ^
                          $self->__push_value($ctx, $v_ref, $fields, $fflags, $ctx->{flag}, $fnum);
                          return 1;
                      }
  
                      if (defined $esc and $c eq $esc) {
                          $quoesc = 1;
                          if (defined $c2 and $c2 eq '0') {
                              # ,1,"foo, 3"056",,bar,\r\n
                              #            ^
                              $$v_ref .= "\0";
                              next;
                          }
                          if (defined $c2 and defined $quot and $c2 eq $quot) {
                              # ,1,"foo, 3""56",,bar,\r\n
                              #            ^
                              if ($ctx->{utf8}) {
                                  $ctx->{flag} |= IS_BINARY;
                              }
                              $$v_ref .= $c2;
                              next;
                          }
                          if ($ctx->{allow_loose_escapes} and defined $c2 and $c2 ne "\015") {
                              # ,1,"foo, 3"56",,bar,\r\n
                              #            ^
                              $$v_ref .= $c;
                              $c = $c2;
                              goto RESTART;
                          }
                      }
                      if (defined $c2 and $c2 eq "\015") {
                          if ($ctx->{eol_is_cr}) {
                              # ,1,"foo, 3"\r
                              #            ^
                              $self->__push_value($ctx, $v_ref, $fields, $fflags, $ctx->{flag}, $fnum);
                              return 1;
                          }
  
                          my $c3 = $self->__get($ctx, $src);
                          if (defined $c3 and $c3 eq "\012") {
                              # ,1,"foo, 3"\r\n
                              #              ^
                              $self->__push_value($ctx, $v_ref, $fields, $fflags, $ctx->{flag}, $fnum);
                              return 1;
                          }
  
                          if ($ctx->{useIO} and !$ctx->{eol_len}) {
                              if ($c3 eq "\015") { # \r followed by an empty line
                                  # ,1,"foo, 3"\r\r
                                  #              ^
                                  $self->__set_eol_is_cr($ctx);
                                  goto EOLX;
                              }
                              if ($c3 !~ /[^\x09\x20-\x7E]/) {
                                  # ,1,"foo\n 3",,"bar"\r
                                  # baz,4
                                  # ^
                                  $self->__set_eol_is_cr($ctx);
                                  $ctx->{used}--;
                                  $ctx->{has_ahead} = 1;
                                  $self->__push_value($ctx, $v_ref, $fields, $fflags, $ctx->{flag}, $fnum);
                                  return 1;
                              }
                          }
  
                          $self->__parse_error($ctx, $quoesc ? 2023 : 2010, $ctx->{used} - 2);
                          return;
                      }
  
                      if ($ctx->{allow_loose_quotes} and !$quoesc) {
                          # ,1,"foo, 3"456",,bar,\r\n
                          #            ^
                          $$v_ref .= $c;
                          $c = $c2;
                          goto RESTART;
                      }
                      # 1,"foo" ",3
                      #        ^
                      if ($quoesc) {
                          $ctx->{used}--;
                          $self->__error_inside_quotes($ctx, 2023);
                          return;
                      }
                      $self->__error_inside_quotes($ctx, 2011);
                      return;
                  }
                  # !waitingForField, !InsideQuotes
                  if ($ctx->{allow_loose_quotes}) { # 1,foo "boo" d'uh,1
                      $ctx->{flag} |= IS_ERROR;
                      $$v_ref .= $c;
                  } else {
                      $self->__error_inside_field($ctx, 2034);
                      return;
                  }
              }
              elsif (defined $c and defined $esc and $esc ne "\0" and $c eq $esc) {
                  # This means quote_char != escape_char
                  if ($waitingForField) {
                      $waitingForField = 0;
                      if ($ctx->{allow_unquoted_escape}) {
                          # The escape character is the first character of an
                          # unquoted field
                          # ... get and store next character
                          my $c2 = $self->__get($ctx, $src);
                          $$v_ref = "";
  
                          if (!defined $c2) { # EOF
                              $ctx->{used}--;
                              $self->__error_inside_field($ctx, 2035);
                              return;
                          }
                          if ($c2 eq '0') {
                              $$v_ref .= "\0";
                          }
                          elsif (
                              (defined $quot and $c2 eq $quot) or
                              (defined $sep and $c2 eq $sep) or
                              (defined $esc and $c2 eq $esc) or
                              $ctx->{allow_loose_escapes}
                          ) {
                              if ($ctx->{utf8}) {
                                  $ctx->{flag} |= IS_BINARY;
                              }
                              $$v_ref .= $c2;
                          } else {
                              $self->__parse_inside_quotes($ctx, 2025);
                              return;
                          }
                      }
                  }
                  elsif ($ctx->{flag} & IS_QUOTED) {
                      my $c2 = $self->__get($ctx, $src);
                      if (!defined $c2) { # EOF
                          $ctx->{used}--;
                          $self->__error_inside_quotes($ctx, 2024);
                          return;
                      }
                      if ($c2 eq '0') {
                          $$v_ref .= "\0";
                      }
                      elsif (
                          (defined $quot and $c2 eq $quot) or
                          (defined $sep and $c2 eq $sep) or
                          (defined $esc and $c2 eq $esc) or
                          $ctx->{allow_loose_escapes}
                      ) {
                          if ($ctx->{utf8}) {
                              $ctx->{flag} |= IS_BINARY;
                          }
                          $$v_ref .= $c2;
                      } else {
                          $ctx->{used}--;
                          $self->__error_inside_quotes($ctx, 2025);
                          return;
                      }
                  }
                  elsif ($v_ref) {
                      my $c2 = $self->__get($ctx, $src);
                      if (!defined $c2) { # EOF
                          $ctx->{used}--;
                          $self->__error_inside_field($ctx, 2035);
                          return;
                      }
                      $$v_ref .= $c2;
                  }
                  else {
                      $self->__error_inside_field($ctx, 2036);
                      return;
                  }
              }
              elsif (defined $c and ($c eq "\012" or $c eq '' or (defined $eol and $c eq $eol and $eol ne "\015"))) { # EOL
      EOLX:
                  if ($fnum == 1 && $ctx->{flag} == 0 && (!$v_ref || $$v_ref eq '') && $ctx->{skip_empty_rows}) {
                      ### SkipEmptyRow
                      my $ser = $ctx->{skip_empty_rows};
                      if ($ser == 3) { $self->SetDiag(2015); die "Empty row\n"; }
                      if ($ser == 4) { $self->SetDiag(2015); die "Empty row\n"; }
                      if ($ser == 5) { $self->SetDiag(2015); return undef; }
  
                      if ($ser <= 2) { # skip & eof
                          $ctx->{fld_idx} = 0;
                          $c = $self->__get($ctx, $src);
                          if (!defined $c or $ser == 2) {  # EOF
                              $v_ref = undef;
                              $seenSomething = 0;
                              if ($ser == 2) { return undef; }
                              last LOOP;
                          }
                      }
  
                      if ($ser == 6) {
                          my $cb = $self->{_EMPTROW_CB};
                          unless ($cb && ref $cb eq 'CODE') {
                              return undef;  # A callback is wanted, but none found
                          }
                          local $_ = $v_ref;
                          my $rv = $cb->();
                          # Result should be a ref to a list.
                          unless (ref $rv eq 'ARRAY') {
                              return undef;
                          }
                          my $n = @$rv;
                          if ($n <= 0) {
                              return 1;
                          }
                          if ($ctx->{is_bound} && $ctx->{is_bound} < $n) {
                              $n = $ctx->{is_bound} - 1;
                          }
                          for (my $i = 0; $i < $n; $i++) {
                              my $rvi = $rv->[$i];
                              $self->__push_value($ctx, \$rvi, $fields, $fflags, $ctx->{flag}, $fnum);
                          }
                          return 1;
                      }
                      goto RESTART;
                  }
  
                  if ($waitingForField) {
                      # ,1,"foo, 3",,bar,
                      #                  ^
                      if ($ctx->{blank_is_undef} or $ctx->{empty_is_undef}) {
                          $$v_ref = undef;
                      } else {
                          $$v_ref = "";
                      }
                      unless ($ctx->{is_bound}) {
                          push @$fields, $$v_ref;
                      }
                      if ($ctx->{keep_meta_info} and $fflags) {
                          push @$fflags, $ctx->{flag};
                      }
                      return 1;
                  }
                  if ($ctx->{flag} & IS_QUOTED) {
                      # ,1,"foo\n 3",,bar,
                      #        ^
                      $ctx->{flag} |= IS_BINARY;
                      unless ($ctx->{binary}) {
                          $self->__error_inside_quotes($ctx, 2021);
                          return;
                      }
                      $$v_ref .= $c;
                  }
                  elsif ($ctx->{verbatim}) {
                      # ,1,foo\n 3,,bar,
                      # This feature should be deprecated
                      $ctx->{flag} |= IS_BINARY;
                      unless ($ctx->{binary}) {
                          $self->__error_inside_field($ctx, 2030);
                          return;
                      }
                      $$v_ref .= $c unless $ctx->{eol} eq $c and $ctx->{useIO};
                  }
                  else {
                      # sep=,
                      #      ^
                      if (!$ctx->{recno} and $ctx->{fld_idx} == 1 and $ctx->{useIO} and $hit =~ /^sep=(.{1,16})$/i) {
                          $ctx->{sep} = $1;
                          use bytes;
                          my $len = length $ctx->{sep};
                          if ($len <= 16) {
                              $ctx->{sep_len} = $len == 1 ? 0 : $len;
                              return $self->____parse($ctx, $src, $fields, $fflags);
                          }
                      }
  
                      # ,1,"foo\n 3",,bar
                      #                  ^
                      $self->__push_value($ctx, $v_ref, $fields, $fflags, $ctx->{flag}, $fnum);
                      return 1;
                  }
              }
              elsif (defined $c and $c eq "\015" and !$ctx->{verbatim}) {
                  if ($waitingForField) {
                      if ($ctx->{eol_is_cr}) {
                          # ,1,"foo\n 3",,bar,\r
                          #                   ^
                          $c = "\012";
                          goto EOLX;
                      }
  
                      my $c2 = $self->__get($ctx, $src);
                      if (!defined $c2) { # EOF
                          # ,1,"foo\n 3",,bar,\r
                          #                     ^
                          $c = undef;
                          last unless $seenSomething;
                          goto RESTART;
                      }
                      if ($c2 eq "\012") { # \r is not optional before EOLX!
                          # ,1,"foo\n 3",,bar,\r\n
                          #                     ^
                          $c = $c2;
                          goto EOLX;
                      }
  
                      if ($ctx->{useIO} and !$ctx->{eol_len}) {
                          if ($c2 eq "\012") { # \r followed by an empty line
                              # ,1,"foo\n 3",,bar,\r\r
                              #                     ^
                              $self->__set_eol_is_cr($ctx);
                              goto EOLX;
                          }
                          $waitingForField = 0;
                          if ($c2 !~ /[^\x09\x20-\x7E]/) {
                              # ,1,"foo\n 3",,bar,\r
                              # baz,4
                              # ^
                              $self->__set_eol_is_cr($ctx);
                              $ctx->{used}--;
                              $ctx->{has_ahead} = 1;
                              if ($fnum == 1 && $ctx->{flag} == 0 && (!$v_ref or $$v_ref eq '') && $ctx->{skip_empty_rows}) {
                                  ### SkipEmptyRow
                                  my $ser = $ctx->{skip_empty_rows};
                                  if ($ser == 3) { $self->SetDiag(2015); die "Empty row\n"; }
                                  if ($ser == 4) { $self->SetDiag(2015); die "Empty row\n"; }
                                  if ($ser == 5) { $self->SetDiag(2015); return undef; }
  
                                  if ($ser <= 2) { # skip & eof
                                      $ctx->{fld_idx} = 0;
                                      $c = $self->__get($ctx, $src);
                                      if (!defined $c) { # EOF
                                          $v_ref = undef;
                                          $waitingForField = 1;
                                          $seenSomething = 0;
                                          last LOOP;
                                      }
                                  }
  
                                  if ($ser == 6) {
                                      my $cb = $self->{_EMPTROW_CB};
                                      unless ($cb && ref $cb eq 'CODE') {
                                          return undef;  # A callback is wanted, but none found
                                      }
                                      local $_ = $v_ref;
                                      my $rv = $cb->();
                                      # Result should be a ref to a list.
                                      unless (ref $rv eq 'ARRAY') {
                                          return undef;
                                      }
                                      my $n = @$rv;
                                      if ($n <= 0) {
                                          return 1;
                                      }
                                      if ($ctx->{is_bound} && $ctx->{is_bound} < $n) {
                                          $n = $ctx->{is_bound} - 1;
                                      }
                                      for (my $i = 0; $i < $n; $i++) {
                                          my $rvi = $rv->[$i];
                                          $self->__push_value($ctx, \$rvi, $fields, $fflags, $ctx->{flag}, $fnum);
                                      }
                                      return 1;
                                  }
  
                                  $$v_ref = $c2;
                                  goto RESTART;
                              }
                              $self->__push_value($ctx, $v_ref, $fields, $fflags, $ctx->{flag}, $fnum);
                              return 1;
                          }
                      }
  
                      # ,1,"foo\n 3",,bar,\r\t
                      #                     ^
                      $ctx->{used}--;
                      $self->__error_inside_field($ctx, 2031);
                      return;
                  }
                  if ($ctx->{flag} & IS_QUOTED) {
                      # ,1,"foo\r 3",,bar,\r\t
                      #        ^
                      $ctx->{flag} |= IS_BINARY;
                      unless ($ctx->{binary}) {
                          $self->__error_inside_quotes($ctx, 2022);
                          return;
                      }
                      $$v_ref .= $c;
                  }
                  else {
                      if ($ctx->{eol_is_cr}) {
                          # ,1,"foo\n 3",,bar\r
                          #                  ^
                          goto EOLX;
                      }
  
                      my $c2 = $self->__get($ctx, $src);
                      if (defined $c2 and $c2 eq "\012") { # \r is not optional before EOLX!
                          # ,1,"foo\n 3",,bar\r\n
                          #                    ^
                          goto EOLX;
                      }
  
                      if ($ctx->{useIO} and !$ctx->{eol_len}) {
                          if ($c2 !~ /[^\x09\x20-\x7E]/
                              # ,1,"foo\n 3",,bar\r
                              # baz,4
                              # ^
                              or $c2 eq "\015"
                              # ,1,"foo\n 3",,bar,\r\r
                              #                     ^
                          ) {
                              $self->__set_eol_is_cr($ctx);
                              $ctx->{used}--;
                              $ctx->{has_ahead} = 1;
                              if ($fnum == 1 && $ctx->{flag} == 0 && (!$v_ref or $$v_ref eq '') && $ctx->{skip_empty_rows}) {
                                  ### SKipEmptyRow
                                  my $ser = $ctx->{skip_empty_rows};
                                  if ($ser == 3) { $self->SetDiag(2015); die "Empty row\n"; }
                                  if ($ser == 4) { $self->SetDiag(2015); die "Empty row\n"; }
                                  if ($ser == 5) { $self->SetDiag(2015); return undef; }
  
                                  if ($ser <= 2) { # skip & eof
                                      $ctx->{fld_idx} = 0;
                                      $c = $self->__get($ctx, $src);
                                      if (!defined $c) { # EOL
                                          $v_ref = undef;
                                          $seenSomething = 0;
                                          last LOOP;
                                      }
                                  }
  
                                  if ($ser == 6) {
                                      my $cb = $self->{_EMPTROW_CB};
                                      unless ($cb && ref $cb eq 'CODE') {
                                          return undef;  # A callback is wanted, but none found
                                      }
                                      local $_ = $v_ref;
                                      my $rv = $cb->();
                                      # Result should be a ref to a list.
                                      unless (ref $rv eq 'ARRAY') {
                                          return undef;
                                      }
                                      my $n = @$rv;
                                      if ($n <= 0) {
                                          return 1;
                                      }
                                      if ($ctx->{is_bound} && $ctx->{is_bound} < $n) {
                                          $n = $ctx->{is_bound} - 1;
                                      }
                                      for (my $i = 0; $i < $n; $i++) {
                                          my $rvi = $rv->[$i];
                                          $self->__push_value($ctx, \$rvi, $fields, $fflags, $ctx->{flag}, $fnum);
                                      }
                                      return 1;
                                  }
                                  goto RESTART;
                              }
                              $self->__push_value($ctx, $v_ref, $fields, $fflags, $ctx->{flag}, $fnum);
                              return 1;
                          }
                      }
  
                      # ,1,"foo\n 3",,bar\r\t
                      #                    ^
                      $self->__error_inside_field($ctx, 2032);
                      return;
                  }
              }
              else {
                  if ($ctx->{eolx} and $c eq $eol) {
                      $c = '';
                      goto EOLX;
                  }
  
                  if ($waitingForField) {
                      if (!$spl && $ctx->{comment_str} && $ctx->{tmp} =~ /\A$ctx->{comment_str}/) {
                          $ctx->{used} = $ctx->{size};
                          $ctx->{fld_idx} = 0;
                          $seenSomething = 0;
                          next LOOP;
                      }
                      if ($ctx->{allow_whitespace} and $self->__is_whitespace($ctx, $c)) {
                          do {
                              $c = $self->__get($ctx, $src);
                              last if !defined $c;
                          } while $self->__is_whitespace($ctx, $c);
                          goto RESTART;
                      }
                      $waitingForField = 0;
                      goto RESTART;
                  }
                  if ($ctx->{flag} & IS_QUOTED) {
                      if (!defined $c or $c =~ /[^\x09\x20-\x7E]/) {
                          $ctx->{flag} |= IS_BINARY;
                          unless ($ctx->{binary} or $ctx->{utf8}) {
                              $self->__error_inside_quotes($ctx, 2026);
                              return;
                          }
                      }
                      $$v_ref .= $c;
                  } else {
                      if (!defined $c or $c =~ /[^\x09\x20-\x7E]/) {
                          last if $ctx->{useIO} && !defined $c;
                          $ctx->{flag} |= IS_BINARY;
                          unless ($ctx->{binary} or $ctx->{utf8}) {
                              $self->__error_inside_field($ctx, 2037);
                              return;
                          }
                      }
                      $$v_ref .= $c;
                  }
              }
              last LOOP if $ctx->{useIO} and $ctx->{verbatim} and $ctx->{used} == $ctx->{size};
          }
      }
  
      if ($waitingForField) {
          if ($seenSomething or !$ctx->{useIO}) {
              # new field
              if (!$v_ref) {
                  if ($ctx->{is_bound}) {
                      $v_ref = $self->__bound_field($ctx, $fnum, 0);
                  } else {
                      $value = '';
                      $v_ref = \$value;
                  }
                  $fnum++;
                  return unless $v_ref;
                  $ctx->{flag} = 0;
                  $ctx->{fld_idx}++;
              }
              if ($ctx->{blank_is_undef} or $ctx->{empty_is_undef}) {
                  $$v_ref = undef;
              } else {
                  $$v_ref = "";
              }
              unless ($ctx->{is_bound}) {
                  push @$fields, $$v_ref;
              }
              if ($ctx->{keep_meta_info} and $fflags) {
                  push @$fflags, $ctx->{flag};
              }
              return 1;
          }
          $self->SetDiag(2012);
          return;
      }
  
      if ($ctx->{flag} & IS_QUOTED) {
          $self->__error_inside_quotes($ctx, 2027);
          return;
      }
  
      if ($v_ref) {
          $self->__push_value($ctx, $v_ref, $fields, $fflags, $ctx->{flag}, $fnum);
      } elsif ($ctx->{flag} == 0 && $fnum == 1 && $ctx->{skip_empty_rows} == 1) {
          return undef;
      }
      return 1;
  }
  
  sub __get_from_src {
      my ($self, $ctx, $src) = @_;
      return 1 if defined $ctx->{tmp} and $ctx->{used} <= 0;
      return 1 if $ctx->{used} < $ctx->{size};
      return unless $ctx->{useIO};
      my $res = $src->getline;
      if (defined $res) {
          if ($ctx->{has_ahead}) {
              $ctx->{tmp} = $self->{_AHEAD};
              $ctx->{tmp} .= $ctx->{eol} if $ctx->{eol_len};
              $ctx->{tmp} .= $res;
              $ctx->{has_ahead} = 0;
          } else {
              $ctx->{tmp} = $res;
          }
          if ($ctx->{size} = length $ctx->{tmp}) {
              $ctx->{used} = -1;
              $ctx->{utf8} = 1 if utf8::is_utf8($ctx->{tmp});
              pos($ctx->{tmp}) = 0;
              return 1;
          }
      } elsif (delete $ctx->{has_leftover}) {
          $ctx->{tmp} = $self->{_AHEAD};
          $ctx->{has_ahead} = 0;
          $ctx->{useIO} |= useIO_EOF;
          if ($ctx->{size} = length $ctx->{tmp}) {
              $ctx->{used} = -1;
              $ctx->{utf8} = 1 if utf8::is_utf8($ctx->{tmp});
              pos($ctx->{tmp}) = 0;
              return 1;
          }
      }
      $ctx->{tmp} = '' unless defined $ctx->{tmp};
      $ctx->{useIO} |= useIO_EOF;
      return;
  }
  
  sub __set_eol_is_cr {
      my ($self, $ctx) = @_;
      $ctx->{eol} = "\015";
      $ctx->{eol_is_cr} = 1;
      $ctx->{eol_len} = 1;
      %{$self->{_CACHE}} = %$ctx;
  
      $self->{eol} = $ctx->{eol};
  }
  
  sub __bound_field {
      my ($self, $ctx, $i, $keep) = @_;
      if ($i >= $ctx->{is_bound}) {
          $self->SetDiag(3006);
          return;
      }
      if (ref $ctx->{bound} eq 'ARRAY') {
          my $ref = $ctx->{bound}[$i];
          if (ref $ref) {
              if ($keep) {
                  return $ref;
              }
              unless (Scalar::Util::readonly($$ref)) {
                  $$ref = "";
                  return $ref;
              }
          }
      }
      $self->SetDiag(3008);
      return;
  }
  
  sub __get {
      my ($self, $ctx, $src) = @_;
      return unless defined $ctx->{used};
      if ($ctx->{used} >= $ctx->{size}) {
          if ($self->__get_from_src($ctx, $src)) {
              return $self->__get($ctx, $src);
          }
          return;
      }
      my $pos = pos($ctx->{tmp});
      if ($ctx->{tmp} =~ /\G($ctx->{_re}|.)/gs) {
          my $c = $1;
          if ($c =~ /[^\x09\012\015\x20-\x7e]/) {
              $ctx->{flag} |= IS_BINARY;
          }
          $ctx->{used} = pos($ctx->{tmp});
          return $c;
      } else {
          if ($self->__get_from_src($ctx, $src)) {
              return $self->__get($ctx, $src);
          }
          pos($ctx->{tmp}) = $pos;
          return;
      }
  }
  
  sub __error_inside_quotes {
      my ($self, $ctx, $error) = @_;
      $self->__parse_error($ctx, $error, $ctx->{used} - 1);
  }
  
  sub __error_inside_field {
      my ($self, $ctx, $error) = @_;
      $self->__parse_error($ctx, $error, $ctx->{used} - 1);
  }
  
  sub __parse_error {
      my ($self, $ctx, $error, $pos) = @_;
      $self->{_ERROR_POS} = $pos;
      $self->{_ERROR_FLD} = $ctx->{fld_idx};
      $self->{_ERROR_INPUT} = $ctx->{tmp} if $ctx->{tmp};
      $self->SetDiag($error);
      return;
  }
  
  sub __is_whitespace {
      my ($self, $ctx, $c) = @_;
      return unless defined $c;
      return (
          (!defined $ctx->{sep} or $c ne $ctx->{sep}) &&
          (!defined $ctx->{quo} or $c ne $ctx->{quo}) &&
          (!defined $ctx->{escape_char} or $c ne $ctx->{escape_char}) &&
          ($c eq " " or $c eq "\t")
      );
  }
  
  sub __push_value { # AV_PUSH (part of)
      my ($self, $ctx, $v_ref, $fields, $fflags, $flag, $fnum) = @_;
      utf8::encode($$v_ref) if $ctx->{utf8};
      if ($ctx->{formula} && defined $$v_ref && substr($$v_ref, 0, 1) eq '=') {
          my $value = $self->_formula($ctx, $$v_ref, $fnum);
          push @$fields, defined $value ? $value : undef;
          return;
      }
      if (
          (!defined $$v_ref or $$v_ref eq '') and
          ($ctx->{empty_is_undef} or (!($flag & IS_QUOTED) and $ctx->{blank_is_undef}))
      ) {
          $$v_ref = undef;
      } else {
          if ($ctx->{allow_whitespace} && !($flag & IS_QUOTED)) {
              $$v_ref =~ s/[ \t]+$//;
          }
          if ($flag & IS_BINARY and $ctx->{decode_utf8} and ($ctx->{utf8} || _is_valid_utf8($$v_ref))) {
              utf8::decode($$v_ref);
          }
      }
      unless ($ctx->{is_bound}) {
          push @$fields, $$v_ref;
      }
      if ($ctx->{keep_meta_info} and $fflags) {
          push @$fflags, $flag;
      }
  }
  
  sub getline {
      my ($self, $io) = @_;
  
      my (@fields, @fflags);
      my $res = $self->__parse(\@fields, \@fflags, $io, 1);
      $res ? \@fields : undef;
  }
  
  sub getline_all {
      my ( $self, $io, $offset, $len ) = @_;
  
      my $ctx = $self->_setup_ctx;
  
      my $tail = 0;
      my $n = 0;
      $offset ||= 0;
  
      if ( $offset < 0 ) {
          $tail = -$offset;
          $offset = -1;
      }
  
      my (@row, @list);
      while ($self->___parse($ctx, \@row, undef, $io, 1)) {
          $ctx = $self->_setup_ctx;
  
          if ($offset > 0) {
              $offset--;
              @row = ();
              next;
          }
          if ($n++ >= $tail and $tail) {
              shift @list;
              $n--;
          }
          if (($ctx->{has_hooks} || 0) & HOOK_AFTER_PARSE) {
              unless ($self->_hook(after_parse => \@row)) {
                  @row = ();
                  next;
              }
          }
          push @list, [@row];
          @row = ();
  
          last if defined $len && $n >= $len and $offset >= 0;   # exceeds limit size
      }
  
      if ( defined $len && $n > $len ) {
          @list = splice( @list, 0, $len);
      }
  
      return \@list;
  }
  
  sub _is_valid_utf8 {
      return ( $_[0] =~ /^(?:
           [\x00-\x7F]
          |[\xC2-\xDF][\x80-\xBF]
          |[\xE0][\xA0-\xBF][\x80-\xBF]
          |[\xE1-\xEC][\x80-\xBF][\x80-\xBF]
          |[\xED][\x80-\x9F][\x80-\xBF]
          |[\xEE-\xEF][\x80-\xBF][\x80-\xBF]
          |[\xF0][\x90-\xBF][\x80-\xBF][\x80-\xBF]
          |[\xF1-\xF3][\x80-\xBF][\x80-\xBF][\x80-\xBF]
          |[\xF4][\x80-\x8F][\x80-\xBF][\x80-\xBF]
      )+$/x )  ? 1 : 0;
  }
  
  ################################################################################
  # methods for errors
  ################################################################################
  
  sub _set_error_diag {
      my ( $self, $error, $pos ) = @_;
  
      $self->SetDiag($error);
  
      if (defined $pos) {
          $_[0]->{_ERROR_POS} = $pos;
      }
  
      return;
  }
  
  sub error_input {
      my $self = shift;
      if ($self and ((Scalar::Util::reftype($self) || '') eq 'HASH' or (ref $self) =~ /^Text::CSV/)) {
          return $self->{_ERROR_INPUT};
      }
      return;
  }
  
  sub _sv_diag {
      my ($self, $error) = @_;
      bless [$error, $ERRORS->{$error}], 'Text::CSV::ErrorDiag';
  }
  
  sub _set_diag {
      my ($self, $ctx, $error) = @_;
  
      $last_error = $self->_sv_diag($error);
      $self->{_ERROR_DIAG} = $last_error;
      if ($error == 0) {
          $self->{_ERROR_POS} = 0;
          $self->{_ERROR_FLD} = 0;
          $self->{_ERROR_INPUT} = undef;
          $ctx->{has_error_input} = 0;
      }
      if ($error == 2012) { # EOF
          $self->{_EOF} = 1;
      }
      if ($ctx->{auto_diag}) {
          $self->error_diag;
      }
      return $last_error;
  }
  
  sub SetDiag {
      my ($self, $error, $errstr) = @_;
      my $res;
      if (ref $self) {
          my $ctx = $self->_setup_ctx;
          $res = $self->_set_diag($ctx, $error);
  
      } else {
          $last_error = $error;
          $res = $self->_sv_diag($error);
      }
      if (defined $errstr) {
          $res->[1] = $errstr;
      }
      $res;
  }
  
  ################################################################################
  package Text::CSV::ErrorDiag;
  
  use strict;
  use overload (
      '""' => \&stringify,
      '+'  => \&numeric,
      '-'  => \&numeric,
      '*'  => \&numeric,
      '/'  => \&numeric,
      fallback => 1,
  );
  
  
  sub numeric {
      my ($left, $right) = @_;
      return ref $left ? $left->[0] : $right->[0];
  }
  
  
  sub stringify {
      $_[0]->[1];
  }
  ################################################################################
  1;
  __END__
  
  =head1 NAME
  
  Text::CSV_PP - Text::CSV_XS compatible pure-Perl module
  
  
  =head1 SYNOPSIS
  
  This section is taken from Text::CSV_XS.
  
   # Functional interface
   use Text::CSV_PP qw( csv );
  
   # Read whole file in memory
   my $aoa = csv (in => "data.csv");    # as array of array
   my $aoh = csv (in => "data.csv",
                  headers => "auto");   # as array of hash
  
   # Write array of arrays as csv file
   csv (in => $aoa, out => "file.csv", sep_char => ";");
  
   # Only show lines where "code" is odd
   csv (in => "data.csv", filter => { code => sub { $_ % 2 }});
  
   # Object interface
   use Text::CSV_PP;
  
   my @rows;
   # Read/parse CSV
   my $csv = Text::CSV_PP->new ({ binary => 1, auto_diag => 1 });
   open my $fh, "<:encoding(utf8)", "test.csv" or die "test.csv: $!";
   while (my $row = $csv->getline ($fh)) {
       $row->[2] =~ m/pattern/ or next; # 3rd field should match
       push @rows, $row;
       }
   close $fh;
  
   # and write as CSV
   open $fh, ">:encoding(utf8)", "new.csv" or die "new.csv: $!";
   $csv->say ($fh, $_) for @rows;
   close $fh or die "new.csv: $!";
  
  =head1 DESCRIPTION
  
  Text::CSV_PP is a pure-perl module that provides facilities for the
  composition and decomposition of comma-separated values. This is
  (almost) compatible with much faster L<Text::CSV_XS>, and mainly
  used as its fallback module when you use L<Text::CSV> module without
  having installed Text::CSV_XS. If you don't have any reason to use
  this module directly, use Text::CSV for speed boost and portability
  (or maybe Text::CSV_XS when you write an one-off script and don't need
  to care about portability).
  
  The following caveats are taken from the doc of Text::CSV_XS.
  
  =head2 Embedded newlines
  
  B<Important Note>:  The default behavior is to accept only ASCII characters
  in the range from C<0x20> (space) to C<0x7E> (tilde).   This means that the
  fields can not contain newlines. If your data contains newlines embedded in
  fields, or characters above C<0x7E> (tilde), or binary data, you B<I<must>>
  set C<< binary => 1 >> in the call to L</new>. To cover the widest range of
  parsing options, you will always want to set binary.
  
  But you still have the problem  that you have to pass a correct line to the
  L</parse> method, which is more complicated from the usual point of usage:
  
   my $csv = Text::CSV_PP->new ({ binary => 1, eol => $/ });
   while (<>) {		#  WRONG!
       $csv->parse ($_);
       my @fields = $csv->fields ();
       }
  
  this will break, as the C<while> might read broken lines:  it does not care
  about the quoting. If you need to support embedded newlines,  the way to go
  is to  B<not>  pass L<C<eol>|/eol> in the parser  (it accepts C<\n>, C<\r>,
  B<and> C<\r\n> by default) and then
  
   my $csv = Text::CSV_PP->new ({ binary => 1 });
   open my $fh, "<", $file or die "$file: $!";
   while (my $row = $csv->getline ($fh)) {
       my @fields = @$row;
       }
  
  The old(er) way of using global file handles is still supported
  
   while (my $row = $csv->getline (*ARGV)) { ... }
  
  =head2 Unicode
  
  Unicode is only tested to work with perl-5.8.2 and up.
  
  See also L</BOM>.
  
  The simplest way to ensure the correct encoding is used for  in- and output
  is by either setting layers on the filehandles, or setting the L</encoding>
  argument for L</csv>.
  
   open my $fh, "<:encoding(UTF-8)", "in.csv"  or die "in.csv: $!";
  or
   my $aoa = csv (in => "in.csv",     encoding => "UTF-8");
  
   open my $fh, ">:encoding(UTF-8)", "out.csv" or die "out.csv: $!";
  or
   csv (in => $aoa, out => "out.csv", encoding => "UTF-8");
  
  On parsing (both for  L</getline> and  L</parse>),  if the source is marked
  being UTF8, then all fields that are marked binary will also be marked UTF8.
  
  On combining (L</print>  and  L</combine>):  if any of the combining fields
  was marked UTF8, the resulting string will be marked as UTF8.  Note however
  that all fields  I<before>  the first field marked UTF8 and contained 8-bit
  characters that were not upgraded to UTF8,  these will be  C<bytes>  in the
  resulting string too, possibly causing unexpected errors.  If you pass data
  of different encoding,  or you don't know if there is  different  encoding,
  force it to be upgraded before you pass them on:
  
   $csv->print ($fh, [ map { utf8::upgrade (my $x = $_); $x } @data ]);
  
  For complete control over encoding, please use L<Text::CSV::Encoded>:
  
   use Text::CSV::Encoded;
   my $csv = Text::CSV::Encoded->new ({
       encoding_in  => "iso-8859-1", # the encoding comes into   Perl
       encoding_out => "cp1252",     # the encoding comes out of Perl
       });
  
   $csv = Text::CSV::Encoded->new ({ encoding  => "utf8" });
   # combine () and print () accept *literally* utf8 encoded data
   # parse () and getline () return *literally* utf8 encoded data
  
   $csv = Text::CSV::Encoded->new ({ encoding  => undef }); # default
   # combine () and print () accept UTF8 marked data
   # parse () and getline () return UTF8 marked data
  
  =head2 BOM
  
  BOM  (or Byte Order Mark)  handling is available only inside the L</header>
  method.   This method supports the following encodings: C<utf-8>, C<utf-1>,
  C<utf-32be>, C<utf-32le>, C<utf-16be>, C<utf-16le>, C<utf-ebcdic>, C<scsu>,
  C<bocu-1>, and C<gb-18030>. See L<Wikipedia|https://en.wikipedia.org/wiki/Byte_order_mark>.
  
  If a file has a BOM, the easiest way to deal with that is
  
   my $aoh = csv (in => $file, detect_bom => 1);
  
  All records will be encoded based on the detected BOM.
  
  This implies a call to the  L</header>  method,  which defaults to also set
  the L</column_names>. So this is B<not> the same as
  
   my $aoh = csv (in => $file, headers => "auto");
  
  which only reads the first record to set  L</column_names>  but ignores any
  meaning of possible present BOM.
  
  =head1 METHODS
  
  This section is also taken from Text::CSV_XS.
  
  =head2 version
  
  (Class method) Returns the current module version.
  
  =head2 new
  
  (Class method) Returns a new instance of class Text::CSV_PP. The attributes
  are described by the (optional) hash ref C<\%attr>.
  
   my $csv = Text::CSV_PP->new ({ attributes ... });
  
  The following attributes are available:
  
  =head3 eol
  
   my $csv = Text::CSV_PP->new ({ eol => $/ });
             $csv->eol (undef);
   my $eol = $csv->eol;
  
  The end-of-line string to add to rows for L</print> or the record separator
  for L</getline>.
  
  When not passed in a B<parser> instance,  the default behavior is to accept
  C<\n>, C<\r>, and C<\r\n>, so it is probably safer to not specify C<eol> at
  all. Passing C<undef> or the empty string behave the same.
  
  When not passed in a B<generating> instance,  records are not terminated at
  all, so it is probably wise to pass something you expect. A safe choice for
  C<eol> on output is either C<$/> or C<\r\n>.
  
  Common values for C<eol> are C<"\012"> (C<\n> or Line Feed),  C<"\015\012">
  (C<\r\n> or Carriage Return, Line Feed),  and C<"\015">  (C<\r> or Carriage
  Return). The L<C<eol>|/eol> attribute cannot exceed 7 (ASCII) characters.
  
  If both C<$/> and L<C<eol>|/eol> equal C<"\015">, parsing lines that end on
  only a Carriage Return without Line Feed, will be L</parse>d correct.
  
  =head3 sep_char
  
   my $csv = Text::CSV_PP->new ({ sep_char => ";" });
           $csv->sep_char (";");
   my $c = $csv->sep_char;
  
  The char used to separate fields, by default a comma. (C<,>).  Limited to a
  single-byte character, usually in the range from C<0x20> (space) to C<0x7E>
  (tilde). When longer sequences are required, use L<C<sep>|/sep>.
  
  The separation character can not be equal to the quote character  or to the
  escape character.
  
  =head3 sep
  
   my $csv = Text::CSV_PP->new ({ sep => "\N{FULLWIDTH COMMA}" });
             $csv->sep (";");
   my $sep = $csv->sep;
  
  The chars used to separate fields, by default undefined. Limited to 8 bytes.
  
  When set, overrules L<C<sep_char>|/sep_char>.  If its length is one byte it
  acts as an alias to L<C<sep_char>|/sep_char>.
  
  =head3 quote_char
  
   my $csv = Text::CSV_PP->new ({ quote_char => "'" });
           $csv->quote_char (undef);
   my $c = $csv->quote_char;
  
  The character to quote fields containing blanks or binary data,  by default
  the double quote character (C<">).  A value of undef suppresses quote chars
  (for simple cases only). Limited to a single-byte character, usually in the
  range from  C<0x20> (space) to  C<0x7E> (tilde).  When longer sequences are
  required, use L<C<quote>|/quote>.
  
  C<quote_char> can not be equal to L<C<sep_char>|/sep_char>.
  
  =head3 quote
  
   my $csv = Text::CSV_PP->new ({ quote => "\N{FULLWIDTH QUOTATION MARK}" });
               $csv->quote ("'");
   my $quote = $csv->quote;
  
  The chars used to quote fields, by default undefined. Limited to 8 bytes.
  
  When set, overrules L<C<quote_char>|/quote_char>. If its length is one byte
  it acts as an alias to L<C<quote_char>|/quote_char>.
  
  This method does not support C<undef>.  Use L<C<quote_char>|/quote_char> to
  disable quotation.
  
  =head3 escape_char
  
   my $csv = Text::CSV_PP->new ({ escape_char => "\\" });
           $csv->escape_char (":");
   my $c = $csv->escape_char;
  
  The character to  escape  certain characters inside quoted fields.  This is
  limited to a  single-byte  character,  usually  in the  range from  C<0x20>
  (space) to C<0x7E> (tilde).
  
  The C<escape_char> defaults to being the double-quote mark (C<">). In other
  words the same as the default L<C<quote_char>|/quote_char>. This means that
  doubling the quote mark in a field escapes it:
  
   "foo","bar","Escape ""quote mark"" with two ""quote marks""","baz"
  
  If  you  change  the   L<C<quote_char>|/quote_char>  without  changing  the
  C<escape_char>,  the  C<escape_char> will still be the double-quote (C<">).
  If instead you want to escape the  L<C<quote_char>|/quote_char> by doubling
  it you will need to also change the  C<escape_char>  to be the same as what
  you have changed the L<C<quote_char>|/quote_char> to.
  
  Setting C<escape_char> to C<undef> or C<""> will completely disable escapes
  and is greatly discouraged. This will also disable C<escape_null>.
  
  The escape character can not be equal to the separation character.
  
  =head3 binary
  
   my $csv = Text::CSV_PP->new ({ binary => 1 });
           $csv->binary (0);
   my $f = $csv->binary;
  
  If this attribute is C<1>,  you may use binary characters in quoted fields,
  including line feeds, carriage returns and C<NULL> bytes. (The latter could
  be escaped as C<"0>.) By default this feature is off.
  
  If a string is marked UTF8,  C<binary> will be turned on automatically when
  binary characters other than C<CR> and C<NL> are encountered.   Note that a
  simple string like C<"\x{00a0}"> might still be binary, but not marked UTF8,
  so setting C<< { binary => 1 } >> is still a wise option.
  
  =head3 strict
  
   my $csv = Text::CSV_PP->new ({ strict => 1 });
           $csv->strict (0);
   my $f = $csv->strict;
  
  If this attribute is set to C<1>, any row that parses to a different number
  of fields than the previous row will cause the parser to throw error 2014.
  
  =head3 skip_empty_rows
  
   my $csv = Text::CSV_PP->new ({ skip_empty_rows => 1 });
           $csv->skip_empty_rows ("eof");
   my $f = $csv->skip_empty_rows;
  
  This attribute defines the behavior for empty rows:  an L</eol> immediately
  following the start of line. Default behavior is to return one single empty
  field.
  
  This attribute is only used in parsing.  This attribute is ineffective when
  using L</parse> and L</fields>.
  
  Possible values for this attribute are
  
  =over 2
  
  =item 0 | undef
  
   my $csv = Text::CSV_PP->new ({ skip_empty_rows => 0 });
   $csv->skip_empty_rows (undef);
  
  No special action is taken. The result will be one single empty field.
  
  =item 1 | "skip"
  
   my $csv = Text::CSV_PP->new ({ skip_empty_rows => 1 });
   $csv->skip_empty_rows ("skip");
  
  The row will be skipped.
  
  =item 2 | "eof" | "stop"
  
   my $csv = Text::CSV_PP->new ({ skip_empty_rows => 2 });
   $csv->skip_empty_rows ("eof");
  
  The parsing will stop as if an L</eof> was detected.
  
  =item 3 | "die"
  
   my $csv = Text::CSV_PP->new ({ skip_empty_rows => 3 });
   $csv->skip_empty_rows ("die");
  
  The parsing will stop.  The internal error code will be set to 2015 and the
  parser will C<die>.
  
  =item 4 | "croak"
  
   my $csv = Text::CSV_PP->new ({ skip_empty_rows => 4 });
   $csv->skip_empty_rows ("croak");
  
  The parsing will stop.  The internal error code will be set to 2015 and the
  parser will C<croak>.
  
  =item 5 | "error"
  
   my $csv = Text::CSV_PP->new ({ skip_empty_rows => 5 });
   $csv->skip_empty_rows ("error");
  
  The parsing will fail.  The internal error code will be set to 2015.
  
  =item callback
  
   my $csv = Text::CSV_PP->new ({ skip_empty_rows => sub { [] } });
   $csv->skip_empty_rows (sub { [ 42, $., undef, "empty" ] });
  
  The callback is invoked and its result used instead.  If you want the parse
  to stop after the callback, make sure to return a false value.
  
  The returned value from the callback should be an array-ref. Any other type
  will cause the parse to stop, so these are equivalent in behavior:
  
   csv (in => $fh, skip_empty_rows => "stop");
   csv (in => $fh. skip_empty_rows => sub { 0; });
  
  =back
  
  Without arguments, the current value is returned: C<0>, C<1>, C<eof>, C<die>,
  C<croak> or the callback.
  
  =head3 formula_handling
  
  Alias for L</formula>
  
  =head3 formula
  
   my $csv = Text::CSV_PP->new ({ formula => "none" });
           $csv->formula ("none");
   my $f = $csv->formula;
  
  This defines the behavior of fields containing I<formulas>. As formulas are
  considered dangerous in spreadsheets, this attribute can define an optional
  action to be taken if a field starts with an equal sign (C<=>).
  
  For purpose of code-readability, this can also be written as
  
   my $csv = Text::CSV_PP->new ({ formula_handling => "none" });
           $csv->formula_handling ("none");
   my $f = $csv->formula_handling;
  
  Possible values for this attribute are
  
  =over 2
  
  =item none
  
  Take no specific action. This is the default.
  
   $csv->formula ("none");
  
  =item die
  
  Cause the process to C<die> whenever a leading C<=> is encountered.
  
   $csv->formula ("die");
  
  =item croak
  
  Cause the process to C<croak> whenever a leading C<=> is encountered.  (See
  L<Carp>)
  
   $csv->formula ("croak");
  
  =item diag
  
  Report position and content of the field whenever a leading  C<=> is found.
  The value of the field is unchanged.
  
   $csv->formula ("diag");
  
  =item empty
  
  Replace the content of fields that start with a C<=> with the empty string.
  
   $csv->formula ("empty");
   $csv->formula ("");
  
  =item undef
  
  Replace the content of fields that start with a C<=> with C<undef>.
  
   $csv->formula ("undef");
   $csv->formula (undef);
  
  =item a callback
  
  Modify the content of fields that start with a  C<=>  with the return-value
  of the callback.  The original content of the field is available inside the
  callback as C<$_>;
  
   # Replace all formula's with 42
   $csv->formula (sub { 42; });
  
   # same as $csv->formula ("empty") but slower
   $csv->formula (sub { "" });
  
   # Allow =4+12
   $csv->formula (sub { s/^=(\d+\+\d+)$/$1/eer });
  
   # Allow more complex calculations
   $csv->formula (sub { eval { s{^=([-+*/0-9()]+)$}{$1}ee }; $_ });
  
  =back
  
  All other values will give a warning and then fallback to C<diag>.
  
  =head3 decode_utf8
  
   my $csv = Text::CSV_PP->new ({ decode_utf8 => 1 });
           $csv->decode_utf8 (0);
   my $f = $csv->decode_utf8;
  
  This attributes defaults to TRUE.
  
  While I<parsing>,  fields that are valid UTF-8, are automatically set to be
  UTF-8, so that
  
    $csv->parse ("\xC4\xA8\n");
  
  results in
  
    PV("\304\250"\0) [UTF8 "\x{128}"]
  
  Sometimes it might not be a desired action.  To prevent those upgrades, set
  this attribute to false, and the result will be
  
    PV("\304\250"\0)
  
  =head3 auto_diag
  
   my $csv = Text::CSV_PP->new ({ auto_diag => 1 });
           $csv->auto_diag (2);
   my $l = $csv->auto_diag;
  
  Set this attribute to a number between C<1> and C<9> causes  L</error_diag>
  to be automatically called in void context upon errors.
  
  In case of error C<2012 - EOF>, this call will be void.
  
  If C<auto_diag> is set to a numeric value greater than C<1>, it will C<die>
  on errors instead of C<warn>.  If set to anything unrecognized,  it will be
  silently ignored.
  
  Future extensions to this feature will include more reliable auto-detection
  of  C<autodie>  being active in the scope of which the error occurred which
  will increment the value of C<auto_diag> with  C<1> the moment the error is
  detected.
  
  =head3 diag_verbose
  
   my $csv = Text::CSV_PP->new ({ diag_verbose => 1 });
           $csv->diag_verbose (2);
   my $l = $csv->diag_verbose;
  
  Set the verbosity of the output triggered by C<auto_diag>.   Currently only
  adds the current  input-record-number  (if known)  to the diagnostic output
  with an indication of the position of the error.
  
  =head3 blank_is_undef
  
   my $csv = Text::CSV_PP->new ({ blank_is_undef => 1 });
           $csv->blank_is_undef (0);
   my $f = $csv->blank_is_undef;
  
  Under normal circumstances, C<CSV> data makes no distinction between quoted-
  and unquoted empty fields.  These both end up in an empty string field once
  read, thus
  
   1,"",," ",2
  
  is read as
  
   ("1", "", "", " ", "2")
  
  When I<writing>  C<CSV> files with either  L<C<always_quote>|/always_quote>
  or  L<C<quote_empty>|/quote_empty> set, the unquoted  I<empty> field is the
  result of an undefined value.   To enable this distinction when  I<reading>
  C<CSV>  data,  the  C<blank_is_undef>  attribute will cause  unquoted empty
  fields to be set to C<undef>, causing the above to be parsed as
  
   ("1", "", undef, " ", "2")
  
  Note that this is specifically important when loading  C<CSV> fields into a
  database that allows C<NULL> values,  as the perl equivalent for C<NULL> is
  C<undef> in L<DBI> land.
  
  =head3 empty_is_undef
  
   my $csv = Text::CSV_PP->new ({ empty_is_undef => 1 });
           $csv->empty_is_undef (0);
   my $f = $csv->empty_is_undef;
  
  Going one  step  further  than  L<C<blank_is_undef>|/blank_is_undef>,  this
  attribute converts all empty fields to C<undef>, so
  
   1,"",," ",2
  
  is read as
  
   (1, undef, undef, " ", 2)
  
  Note that this affects only fields that are  originally  empty,  not fields
  that are empty after stripping allowed whitespace. YMMV.
  
  =head3 allow_whitespace
  
   my $csv = Text::CSV_PP->new ({ allow_whitespace => 1 });
           $csv->allow_whitespace (0);
   my $f = $csv->allow_whitespace;
  
  When this option is set to true,  the whitespace  (C<TAB>'s and C<SPACE>'s)
  surrounding  the  separation character  is removed when parsing.  If either
  C<TAB> or C<SPACE> is one of the three characters L<C<sep_char>|/sep_char>,
  L<C<quote_char>|/quote_char>, or L<C<escape_char>|/escape_char> it will not
  be considered whitespace.
  
  Now lines like:
  
   1 , "foo" , bar , 3 , zapp
  
  are parsed as valid C<CSV>, even though it violates the C<CSV> specs.
  
  Note that  B<all>  whitespace is stripped from both  start and  end of each
  field.  That would make it  I<more> than a I<feature> to enable parsing bad
  C<CSV> lines, as
  
   1,   2.0,  3,   ape  , monkey
  
  will now be parsed as
  
   ("1", "2.0", "3", "ape", "monkey")
  
  even if the original line was perfectly acceptable C<CSV>.
  
  =head3 allow_loose_quotes
  
   my $csv = Text::CSV_PP->new ({ allow_loose_quotes => 1 });
           $csv->allow_loose_quotes (0);
   my $f = $csv->allow_loose_quotes;
  
  By default, parsing unquoted fields containing L<C<quote_char>|/quote_char>
  characters like
  
   1,foo "bar" baz,42
  
  would result in parse error 2034.  Though it is still bad practice to allow
  this format,  we  cannot  help  the  fact  that  some  vendors  make  their
  applications spit out lines styled this way.
  
  If there is B<really> bad C<CSV> data, like
  
   1,"foo "bar" baz",42
  
  or
  
   1,""foo bar baz"",42
  
  there is a way to get this data-line parsed and leave the quotes inside the
  quoted field as-is.  This can be achieved by setting  C<allow_loose_quotes>
  B<AND> making sure that the L<C<escape_char>|/escape_char> is  I<not> equal
  to L<C<quote_char>|/quote_char>.
  
  =head3 allow_loose_escapes
  
   my $csv = Text::CSV_PP->new ({ allow_loose_escapes => 1 });
           $csv->allow_loose_escapes (0);
   my $f = $csv->allow_loose_escapes;
  
  Parsing fields  that  have  L<C<escape_char>|/escape_char>  characters that
  escape characters that do not need to be escaped, like:
  
   my $csv = Text::CSV_PP->new ({ escape_char => "\\" });
   $csv->parse (qq{1,"my bar\'s",baz,42});
  
  would result in parse error 2025.   Though it is bad practice to allow this
  format,  this attribute enables you to treat all escape character sequences
  equal.
  
  =head3 allow_unquoted_escape
  
   my $csv = Text::CSV_PP->new ({ allow_unquoted_escape => 1 });
           $csv->allow_unquoted_escape (0);
   my $f = $csv->allow_unquoted_escape;
  
  A backward compatibility issue where L<C<escape_char>|/escape_char> differs
  from L<C<quote_char>|/quote_char>  prevents  L<C<escape_char>|/escape_char>
  to be in the first position of a field.  If L<C<quote_char>|/quote_char> is
  equal to the default C<"> and L<C<escape_char>|/escape_char> is set to C<\>,
  this would be illegal:
  
   1,\0,2
  
  Setting this attribute to C<1>  might help to overcome issues with backward
  compatibility and allow this style.
  
  =head3 always_quote
  
   my $csv = Text::CSV_PP->new ({ always_quote => 1 });
           $csv->always_quote (0);
   my $f = $csv->always_quote;
  
  By default the generated fields are quoted only if they I<need> to be.  For
  example, if they contain the separator character. If you set this attribute
  to C<1> then I<all> defined fields will be quoted. (C<undef> fields are not
  quoted, see L</blank_is_undef>). This makes it quite often easier to handle
  exported data in external applications.
  
  =head3 quote_space
  
   my $csv = Text::CSV_PP->new ({ quote_space => 1 });
           $csv->quote_space (0);
   my $f = $csv->quote_space;
  
  By default,  a space in a field would trigger quotation.  As no rule exists
  this to be forced in C<CSV>,  nor any for the opposite, the default is true
  for safety.   You can exclude the space  from this trigger  by setting this
  attribute to 0.
  
  =head3 quote_empty
  
   my $csv = Text::CSV_PP->new ({ quote_empty => 1 });
           $csv->quote_empty (0);
   my $f = $csv->quote_empty;
  
  By default the generated fields are quoted only if they I<need> to be.   An
  empty (defined) field does not need quotation. If you set this attribute to
  C<1> then I<empty> defined fields will be quoted.  (C<undef> fields are not
  quoted, see L</blank_is_undef>). See also L<C<always_quote>|/always_quote>.
  
  =head3 quote_binary
  
   my $csv = Text::CSV_PP->new ({ quote_binary => 1 });
           $csv->quote_binary (0);
   my $f = $csv->quote_binary;
  
  By default,  all "unsafe" bytes inside a string cause the combined field to
  be quoted.  By setting this attribute to C<0>, you can disable that trigger
  for bytes C<< >= 0x7F >>.
  
  =head3 escape_null
  
   my $csv = Text::CSV_PP->new ({ escape_null => 1 });
           $csv->escape_null (0);
   my $f = $csv->escape_null;
  
  By default, a C<NULL> byte in a field would be escaped. This option enables
  you to treat the  C<NULL>  byte as a simple binary character in binary mode
  (the C<< { binary => 1 } >> is set).  The default is true.  You can prevent
  C<NULL> escapes by setting this attribute to C<0>.
  
  When the C<escape_char> attribute is set to undefined,  this attribute will
  be set to false.
  
  The default setting will encode "=\x00=" as
  
   "="0="
  
  With C<escape_null> set, this will result in
  
   "=\x00="
  
  The default when using the C<csv> function is C<false>.
  
  For backward compatibility reasons,  the deprecated old name  C<quote_null>
  is still recognized.
  
  =head3 keep_meta_info
  
   my $csv = Text::CSV_PP->new ({ keep_meta_info => 1 });
           $csv->keep_meta_info (0);
   my $f = $csv->keep_meta_info;
  
  By default, the parsing of input records is as simple and fast as possible.
  However,  some parsing information - like quotation of the original field -
  is lost in that process.  Setting this flag to true enables retrieving that
  information after parsing with  the methods  L</meta_info>,  L</is_quoted>,
  and L</is_binary> described below.  Default is false for performance.
  
  If you set this attribute to a value greater than 9,   then you can control
  output quotation style like it was used in the input of the the last parsed
  record (unless quotation was added because of other reasons).
  
   my $csv = Text::CSV_PP->new ({
      binary         => 1,
      keep_meta_info => 1,
      quote_space    => 0,
      });
  
   my $row = $csv->parse (q{1,,"", ," ",f,"g","h""h",help,"help"});
  
   $csv->print (*STDOUT, \@row);
   # 1,,, , ,f,g,"h""h",help,help
   $csv->keep_meta_info (11);
   $csv->print (*STDOUT, \@row);
   # 1,,"", ," ",f,"g","h""h",help,"help"
  
  =head3 undef_str
  
   my $csv = Text::CSV_PP->new ({ undef_str => "\\N" });
           $csv->undef_str (undef);
   my $s = $csv->undef_str;
  
  This attribute optionally defines the output of undefined fields. The value
  passed is not changed at all, so if it needs quotation, the quotation needs
  to be included in the value of the attribute.  Use with caution, as passing
  a value like  C<",",,,,""">  will for sure mess up your output. The default
  for this attribute is C<undef>, meaning no special treatment.
  
  This attribute is useful when exporting  CSV data  to be imported in custom
  loaders, like for MySQL, that recognize special sequences for C<NULL> data.
  
  This attribute has no meaning when parsing CSV data.
  
  =head3 comment_str
  
   my $csv = Text::CSV_PP->new ({ comment_str => "#" });
           $csv->comment_str (undef);
   my $s = $csv->comment_str;
  
  This attribute optionally defines a string to be recognized as comment.  If
  this attribute is defined,   all lines starting with this sequence will not
  be parsed as CSV but skipped as comment.
  
  This attribute has no meaning when generating CSV.
  
  Comment strings that start with any of the special characters/sequences are
  not supported (so it cannot start with any of L</sep_char>, L</quote_char>,
  L</escape_char>, L</sep>, L</quote>, or L</eol>).
  
  For convenience, C<comment> is an alias for C<comment_str>.
  
  =head3 verbatim
  
   my $csv = Text::CSV_PP->new ({ verbatim => 1 });
           $csv->verbatim (0);
   my $f = $csv->verbatim;
  
  This is a quite controversial attribute to set,  but makes some hard things
  possible.
  
  The rationale behind this attribute is to tell the parser that the normally
  special characters newline (C<NL>) and Carriage Return (C<CR>)  will not be
  special when this flag is set,  and be dealt with  as being ordinary binary
  characters. This will ease working with data with embedded newlines.
  
  When  C<verbatim>  is used with  L</getline>,  L</getline>  auto-C<chomp>'s
  every line.
  
  Imagine a file format like
  
   M^^Hans^Janssen^Klas 2\n2A^Ja^11-06-2007#\r\n
  
  where, the line ending is a very specific C<"#\r\n">, and the sep_char is a
  C<^> (caret).   None of the fields is quoted,   but embedded binary data is
  likely to be present. With the specific line ending, this should not be too
  hard to detect.
  
  By default,  Text::CSV_PP'  parse function is instructed to only know about
  C<"\n"> and C<"\r">  to be legal line endings,  and so has to deal with the
  embedded newline as a real C<end-of-line>,  so it can scan the next line if
  binary is true, and the newline is inside a quoted field. With this option,
  we tell L</parse> to parse the line as if C<"\n"> is just nothing more than
  a binary character.
  
  For L</parse> this means that the parser has no more idea about line ending
  and L</getline> C<chomp>s line endings on reading.
  
  =head3 types
  
  A set of column types; the attribute is immediately passed to the L</types>
  method.
  
  =head3 callbacks
  
  See the L</Callbacks> section below.
  
  =head3 accessors
  
  To sum it up,
  
   $csv = Text::CSV_PP->new ();
  
  is equivalent to
  
   $csv = Text::CSV_PP->new ({
       eol                   => undef, # \r, \n, or \r\n
       sep_char              => ',',
       sep                   => undef,
       quote_char            => '"',
       quote                 => undef,
       escape_char           => '"',
       binary                => 0,
       decode_utf8           => 1,
       auto_diag             => 0,
       diag_verbose          => 0,
       blank_is_undef        => 0,
       empty_is_undef        => 0,
       allow_whitespace      => 0,
       allow_loose_quotes    => 0,
       allow_loose_escapes   => 0,
       allow_unquoted_escape => 0,
       always_quote          => 0,
       quote_empty           => 0,
       quote_space           => 1,
       escape_null           => 1,
       quote_binary          => 1,
       keep_meta_info        => 0,
       strict                => 0,
       skip_empty_rows       => 0,
       formula               => 0,
       verbatim              => 0,
       undef_str             => undef,
       comment_str           => undef,
       types                 => undef,
       callbacks             => undef,
       });
  
  For all of the above mentioned flags, an accessor method is available where
  you can inquire the current value, or change the value
  
   my $quote = $csv->quote_char;
   $csv->binary (1);
  
  It is not wise to change these settings halfway through writing C<CSV> data
  to a stream. If however you want to create a new stream using the available
  C<CSV> object, there is no harm in changing them.
  
  If the L</new> constructor call fails,  it returns C<undef>,  and makes the
  fail reason available through the L</error_diag> method.
  
   $csv = Text::CSV_PP->new ({ ecs_char => 1 }) or
       die "".Text::CSV_PP->error_diag ();
  
  L</error_diag> will return a string like
  
   "INI - Unknown attribute 'ecs_char'"
  
  =head2 known_attributes
  
   @attr = Text::CSV_PP->known_attributes;
   @attr = Text::CSV_PP::known_attributes;
   @attr = $csv->known_attributes;
  
  This method will return an ordered list of all the supported  attributes as
  described above.   This can be useful for knowing what attributes are valid
  in classes that use or extend Text::CSV_PP.
  
  =head2 print
  
   $status = $csv->print ($fh, $colref);
  
  Similar to  L</combine> + L</string> + L</print>,  but much more efficient.
  It expects an array ref as input  (not an array!)  and the resulting string
  is not really  created,  but  immediately  written  to the  C<$fh>  object,
  typically an IO handle or any other object that offers a L</print> method.
  
  For performance reasons  C<print>  does not create a result string,  so all
  L</string>, L</status>, L</fields>, and L</error_input> methods will return
  undefined information after executing this method.
  
  If C<$colref> is C<undef>  (explicit,  not through a variable argument) and
  L</bind_columns>  was used to specify fields to be printed,  it is possible
  to make performance improvements, as otherwise data would have to be copied
  as arguments to the method call:
  
   $csv->bind_columns (\($foo, $bar));
   $status = $csv->print ($fh, undef);
  
  A short benchmark
  
   my @data = ("aa" .. "zz");
   $csv->bind_columns (\(@data));
  
   $csv->print ($fh, [ @data ]);   # 11800 recs/sec
   $csv->print ($fh,  \@data  );   # 57600 recs/sec
   $csv->print ($fh,   undef  );   # 48500 recs/sec
  
  =head2 say
  
   $status = $csv->say ($fh, $colref);
  
  Like L<C<print>|/print>, but L<C<eol>|/eol> defaults to C<$\>.
  
  =head2 print_hr
  
   $csv->print_hr ($fh, $ref);
  
  Provides an easy way  to print a  C<$ref>  (as fetched with L</getline_hr>)
  provided the column names are set with L</column_names>.
  
  It is just a wrapper method with basic parameter checks over
  
   $csv->print ($fh, [ map { $ref->{$_} } $csv->column_names ]);
  
  =head2 combine
  
   $status = $csv->combine (@fields);
  
  This method constructs a C<CSV> record from  C<@fields>,  returning success
  or failure.   Failure can result from lack of arguments or an argument that
  contains an invalid character.   Upon success,  L</string> can be called to
  retrieve the resultant C<CSV> string.  Upon failure,  the value returned by
  L</string> is undefined and L</error_input> could be called to retrieve the
  invalid argument.
  
  =head2 string
  
   $line = $csv->string ();
  
  This method returns the input to  L</parse>  or the resultant C<CSV> string
  of L</combine>, whichever was called more recently.
  
  =head2 getline
  
   $colref = $csv->getline ($fh);
  
  This is the counterpart to  L</print>,  as L</parse>  is the counterpart to
  L</combine>:  it parses a row from the C<$fh>  handle using the L</getline>
  method associated with C<$fh>  and parses this row into an array ref.  This
  array ref is returned by the function or C<undef> for failure.  When C<$fh>
  does not support C<getline>, you are likely to hit errors.
  
  When fields are bound with L</bind_columns> the return value is a reference
  to an empty list.
  
  The L</string>, L</fields>, and L</status> methods are meaningless again.
  
  =head2 getline_all
  
   $arrayref = $csv->getline_all ($fh);
   $arrayref = $csv->getline_all ($fh, $offset);
   $arrayref = $csv->getline_all ($fh, $offset, $length);
  
  This will return a reference to a list of L<getline ($fh)|/getline> results.
  In this call, C<keep_meta_info> is disabled.  If C<$offset> is negative, as
  with C<splice>, only the last  C<abs ($offset)> records of C<$fh> are taken
  into consideration. Parameters C<$offset> and C<$length> are expected to be
  integers. Non-integer values are interpreted as integer without check.
  
  Given a CSV file with 10 lines:
  
   lines call
   ----- ---------------------------------------------------------
   0..9  $csv->getline_all ($fh)         # all
   0..9  $csv->getline_all ($fh,  0)     # all
   8..9  $csv->getline_all ($fh,  8)     # start at 8
   -     $csv->getline_all ($fh,  0,  0) # start at 0 first 0 rows
   0..4  $csv->getline_all ($fh,  0,  5) # start at 0 first 5 rows
   4..5  $csv->getline_all ($fh,  4,  2) # start at 4 first 2 rows
   8..9  $csv->getline_all ($fh, -2)     # last 2 rows
   6..7  $csv->getline_all ($fh, -4,  2) # first 2 of last  4 rows
  
  =head2 getline_hr
  
  The L</getline_hr> and L</column_names> methods work together  to allow you
  to have rows returned as hashrefs.  You must call L</column_names> first to
  declare your column names.
  
   $csv->column_names (qw( code name price description ));
   $hr = $csv->getline_hr ($fh);
   print "Price for $hr->{name} is $hr->{price} EUR\n";
  
  L</getline_hr> will croak if called before L</column_names>.
  
  Note that  L</getline_hr>  creates a hashref for every row and will be much
  slower than the combined use of L</bind_columns>  and L</getline> but still
  offering the same easy to use hashref inside the loop:
  
   my @cols = @{$csv->getline ($fh)};
   $csv->column_names (@cols);
   while (my $row = $csv->getline_hr ($fh)) {
       print $row->{price};
       }
  
  Could easily be rewritten to the much faster:
  
   my @cols = @{$csv->getline ($fh)};
   my $row = {};
   $csv->bind_columns (\@{$row}{@cols});
   while ($csv->getline ($fh)) {
       print $row->{price};
       }
  
  Your mileage may vary for the size of the data and the number of rows. With
  perl-5.14.2 the comparison for a 100_000 line file with 14 columns:
  
              Rate hashrefs getlines
   hashrefs 1.00/s       --     -76%
   getlines 4.15/s     313%       --
  
  =head2 getline_hr_all
  
   $arrayref = $csv->getline_hr_all ($fh);
   $arrayref = $csv->getline_hr_all ($fh, $offset);
   $arrayref = $csv->getline_hr_all ($fh, $offset, $length);
  
  This will return a reference to a list of   L<getline_hr ($fh)|/getline_hr>
  results.  In this call, L<C<keep_meta_info>|/keep_meta_info> is disabled.
  
  =head2 parse
  
   $status = $csv->parse ($line);
  
  This method decomposes a  C<CSV>  string into fields,  returning success or
  failure.   Failure can result from a lack of argument  or the given  C<CSV>
  string is improperly formatted.   Upon success, L</fields> can be called to
  retrieve the decomposed fields. Upon failure calling L</fields> will return
  undefined data and  L</error_input>  can be called to retrieve  the invalid
  argument.
  
  You may use the L</types>  method for setting column types.  See L</types>'
  description below.
  
  The C<$line> argument is supposed to be a simple scalar. Everything else is
  supposed to croak and set error 1500.
  
  =head2 fragment
  
  This function tries to implement RFC7111  (URI Fragment Identifiers for the
  text/csv Media Type) - https://datatracker.ietf.org/doc/html/rfc7111
  
   my $AoA = $csv->fragment ($fh, $spec);
  
  In specifications,  C<*> is used to specify the I<last> item, a dash (C<->)
  to indicate a range.   All indices are C<1>-based:  the first row or column
  has index C<1>. Selections can be combined with the semi-colon (C<;>).
  
  When using this method in combination with  L</column_names>,  the returned
  reference  will point to a  list of hashes  instead of a  list of lists.  A
  disjointed  cell-based combined selection  might return rows with different
  number of columns making the use of hashes unpredictable.
  
   $csv->column_names ("Name", "Age");
   my $AoH = $csv->fragment ($fh, "col=3;8");
  
  If the L</after_parse> callback is active,  it is also called on every line
  parsed and skipped before the fragment.
  
  =over 2
  
  =item row
  
   row=4
   row=5-7
   row=6-*
   row=1-2;4;6-*
  
  =item col
  
   col=2
   col=1-3
   col=4-*
   col=1-2;4;7-*
  
  =item cell
  
  In cell-based selection, the comma (C<,>) is used to pair row and column
  
   cell=4,1
  
  The range operator (C<->) using C<cell>s can be used to define top-left and
  bottom-right C<cell> location
  
   cell=3,1-4,6
  
  The C<*> is only allowed in the second part of a pair
  
   cell=3,2-*,2    # row 3 till end, only column 2
   cell=3,2-3,*    # column 2 till end, only row 3
   cell=3,2-*,*    # strip row 1 and 2, and column 1
  
  Cells and cell ranges may be combined with C<;>, possibly resulting in rows
  with different numbers of columns
  
   cell=1,1-2,2;3,3-4,4;1,4;4,1
  
  Disjointed selections will only return selected cells.   The cells that are
  not  specified  will  not  be  included  in the  returned set,  not even as
  C<undef>.  As an example given a C<CSV> like
  
   11,12,13,...19
   21,22,...28,29
   :            :
   91,...97,98,99
  
  with C<cell=1,1-2,2;3,3-4,4;1,4;4,1> will return:
  
   11,12,14
   21,22
   33,34
   41,43,44
  
  Overlapping cell-specs will return those cells only once, So
  C<cell=1,1-3,3;2,2-4,4;2,3;4,2> will return:
  
   11,12,13
   21,22,23,24
   31,32,33,34
   42,43,44
  
  =back
  
  L<RFC7111|https://datatracker.ietf.org/doc/html/rfc7111> does  B<not>  allow different
  types of specs to be combined   (either C<row> I<or> C<col> I<or> C<cell>).
  Passing an invalid fragment specification will croak and set error 2013.
  
  =head2 column_names
  
  Set the "keys" that will be used in the  L</getline_hr>  calls.  If no keys
  (column names) are passed, it will return the current setting as a list.
  
  L</column_names> accepts a list of scalars  (the column names)  or a single
  array_ref, so you can pass the return value from L</getline> too:
  
   $csv->column_names ($csv->getline ($fh));
  
  L</column_names> does B<no> checking on duplicates at all, which might lead
  to unexpected results.   Undefined entries will be replaced with the string
  C<"\cAUNDEF\cA">, so
  
   $csv->column_names (undef, "", "name", "name");
   $hr = $csv->getline_hr ($fh);
  
  will set C<< $hr->{"\cAUNDEF\cA"} >> to the 1st field,  C<< $hr->{""} >> to
  the 2nd field, and C<< $hr->{name} >> to the 4th field,  discarding the 3rd
  field.
  
  L</column_names> croaks on invalid arguments.
  
  =head2 header
  
  This method does NOT work in perl-5.6.x
  
  Parse the CSV header and set L<C<sep>|/sep>, column_names and encoding.
  
   my @hdr = $csv->header ($fh);
   $csv->header ($fh, { sep_set => [ ";", ",", "|", "\t" ] });
   $csv->header ($fh, { detect_bom => 1, munge_column_names => "lc" });
  
  The first argument should be a file handle.
  
  This method resets some object properties,  as it is supposed to be invoked
  only once per file or stream.  It will leave attributes C<column_names> and
  C<bound_columns> alone if setting column names is disabled. Reading headers
  on previously process objects might fail on perl-5.8.0 and older.
  
  Assuming that the file opened for parsing has a header, and the header does
  not contain problematic characters like embedded newlines,   read the first
  line from the open handle then auto-detect whether the header separates the
  column names with a character from the allowed separator list.
  
  If any of the allowed separators matches,  and none of the I<other> allowed
  separators match,  set  L<C<sep>|/sep>  to that  separator  for the current
  CSV_PP instance and use it to parse the first line, map those to lowercase,
  and use that to set the instance L</column_names>:
  
   my $csv = Text::CSV_PP->new ({ binary => 1, auto_diag => 1 });
   open my $fh, "<", "file.csv";
   binmode $fh; # for Windows
   $csv->header ($fh);
   while (my $row = $csv->getline_hr ($fh)) {
       ...
       }
  
  If the header is empty,  contains more than one unique separator out of the
  allowed set,  contains empty fields,   or contains identical fields  (after
  folding), it will croak with error 1010, 1011, 1012, or 1013 respectively.
  
  If the header contains embedded newlines or is not valid  CSV  in any other
  way, this method will croak and leave the parse error untouched.
  
  A successful call to C<header>  will always set the  L<C<sep>|/sep>  of the
  C<$csv> object. This behavior can not be disabled.
  
  =head3 return value
  
  On error this method will croak.
  
  In list context,  the headers will be returned whether they are used to set
  L</column_names> or not.
  
  In scalar context, the instance itself is returned.  B<Note>: the values as
  found in the header will effectively be  B<lost> if  C<set_column_names> is
  false.
  
  =head3 Options
  
  =over 2
  
  =item sep_set
  
   $csv->header ($fh, { sep_set => [ ";", ",", "|", "\t" ] });
  
  The list of legal separators defaults to C<[ ";", "," ]> and can be changed
  by this option.  As this is probably the most often used option,  it can be
  passed on its own as an unnamed argument:
  
   $csv->header ($fh, [ ";", ",", "|", "\t", "::", "\x{2063}" ]);
  
  Multi-byte  sequences are allowed,  both multi-character and  Unicode.  See
  L<C<sep>|/sep>.
  
  =item detect_bom
  
   $csv->header ($fh, { detect_bom => 1 });
  
  The default behavior is to detect if the header line starts with a BOM.  If
  the header has a BOM, use that to set the encoding of C<$fh>.  This default
  behavior can be disabled by passing a false value to C<detect_bom>.
  
  Supported encodings from BOM are: UTF-8, UTF-16BE, UTF-16LE, UTF-32BE,  and
  UTF-32LE. BOM also supports UTF-1, UTF-EBCDIC, SCSU, BOCU-1,  and GB-18030
  but L<Encode> does not (yet). UTF-7 is not supported.
  
  If a supported BOM was detected as start of the stream, it is stored in the
  object attribute C<ENCODING>.
  
   my $enc = $csv->{ENCODING};
  
  The encoding is used with C<binmode> on C<$fh>.
  
  If the handle was opened in a (correct) encoding,  this method will  B<not>
  alter the encoding, as it checks the leading B<bytes> of the first line. In
  case the stream starts with a decoded BOM (C<U+FEFF>), C<{ENCODING}> will be
  C<""> (empty) instead of the default C<undef>.
  
  =item munge_column_names
  
  This option offers the means to modify the column names into something that
  is most useful to the application.   The default is to map all column names
  to lower case.
  
   $csv->header ($fh, { munge_column_names => "lc" });
  
  The following values are available:
  
    lc     - lower case
    uc     - upper case
    db     - valid DB field names
    none   - do not change
    \%hash - supply a mapping
    \&cb   - supply a callback
  
  =over 2
  
  =item Lower case
  
   $csv->header ($fh, { munge_column_names => "lc" });
  
  The header is changed to all lower-case
  
   $_ = lc;
  
  =item Upper case
  
   $csv->header ($fh, { munge_column_names => "uc" });
  
  The header is changed to all upper-case
  
   $_ = uc;
  
  =item Literal
  
   $csv->header ($fh, { munge_column_names => "none" });
  
  =item Hash
  
   $csv->header ($fh, { munge_column_names => { foo => "sombrero" });
  
  if a value does not exist, the original value is used unchanged
  
  =item Database
  
   $csv->header ($fh, { munge_column_names => "db" });
  
  =over 2
  
  =item -
  
  lower-case
  
  =item -
  
  all sequences of non-word characters are replaced with an underscore
  
  =item -
  
  all leading underscores are removed
  
  =back
  
   $_ = lc (s/\W+/_/gr =~ s/^_+//r);
  
  =item Callback
  
   $csv->header ($fh, { munge_column_names => sub { fc } });
   $csv->header ($fh, { munge_column_names => sub { "column_".$col++ } });
   $csv->header ($fh, { munge_column_names => sub { lc (s/\W+/_/gr) } });
  
  As this callback is called in a C<map>, you can use C<$_> directly.
  
  =back
  
  =item set_column_names
  
   $csv->header ($fh, { set_column_names => 1 });
  
  The default is to set the instances column names using  L</column_names> if
  the method is successful,  so subsequent calls to L</getline_hr> can return
  a hash. Disable setting the header can be forced by using a false value for
  this option.
  
  As described in L</return value> above, content is lost in scalar context.
  
  =back
  
  =head3 Validation
  
  When receiving CSV files from external sources,  this method can be used to
  protect against changes in the layout by restricting to known headers  (and
  typos in the header fields).
  
   my %known = (
       "record key" => "c_rec",
       "rec id"     => "c_rec",
       "id_rec"     => "c_rec",
       "kode"       => "code",
       "code"       => "code",
       "vaule"      => "value",
       "value"      => "value",
       );
   my $csv = Text::CSV_PP->new ({ binary => 1, auto_diag => 1 });
   open my $fh, "<", $source or die "$source: $!";
   $csv->header ($fh, { munge_column_names => sub {
       s/\s+$//;
       s/^\s+//;
       $known{lc $_} or die "Unknown column '$_' in $source";
       }});
   while (my $row = $csv->getline_hr ($fh)) {
       say join "\t", $row->{c_rec}, $row->{code}, $row->{value};
       }
  
  =head2 bind_columns
  
  Takes a list of scalar references to be used for output with  L</print>  or
  to store in the fields fetched by L</getline>.  When you do not pass enough
  references to store the fetched fields in, L</getline> will fail with error
  C<3006>.  If you pass more than there are fields to return,  the content of
  the remaining references is left untouched.
  
   $csv->bind_columns (\$code, \$name, \$price, \$description);
   while ($csv->getline ($fh)) {
       print "The price of a $name is \x{20ac} $price\n";
       }
  
  To reset or clear all column binding, call L</bind_columns> with the single
  argument C<undef>. This will also clear column names.
  
   $csv->bind_columns (undef);
  
  If no arguments are passed at all, L</bind_columns> will return the list of
  current bindings or C<undef> if no binds are active.
  
  Note that in parsing with  C<bind_columns>,  the fields are set on the fly.
  That implies that if the third field of a row causes an error  (or this row
  has just two fields where the previous row had more),  the first two fields
  already have been assigned the values of the current row, while the rest of
  the fields will still hold the values of the previous row.  If you want the
  parser to fail in these cases, use the L<C<strict>|/strict> attribute.
  
  =head2 eof
  
   $eof = $csv->eof ();
  
  If L</parse> or  L</getline>  was used with an IO stream,  this method will
  return true (1) if the last call hit end of file,  otherwise it will return
  false ('').  This is useful to see the difference between a failure and end
  of file.
  
  Note that if the parsing of the last line caused an error,  C<eof> is still
  true.  That means that if you are I<not> using L</auto_diag>, an idiom like
  
   while (my $row = $csv->getline ($fh)) {
       # ...
       }
   $csv->eof or $csv->error_diag;
  
  will I<not> report the error. You would have to change that to
  
   while (my $row = $csv->getline ($fh)) {
       # ...
       }
   +$csv->error_diag and $csv->error_diag;
  
  =head2 types
  
   $csv->types (\@tref);
  
  This method is used to force that  (all)  columns are of a given type.  For
  example, if you have an integer column,  two  columns  with  doubles  and a
  string column, then you might do a
  
   $csv->types ([Text::CSV_PP::IV (),
                 Text::CSV_PP::NV (),
                 Text::CSV_PP::NV (),
                 Text::CSV_PP::PV ()]);
  
  Column types are used only for I<decoding> columns while parsing,  in other
  words by the L</parse> and L</getline> methods.
  
  You can unset column types by doing a
  
   $csv->types (undef);
  
  or fetch the current type settings with
  
   $types = $csv->types ();
  
  =over 4
  
  =item IV
  
  =item CSV_TYPE_IV
  
  Set field type to integer.
  
  =item NV
  
  =item CSV_TYPE_NV
  
  Set field type to numeric/float.
  
  =item PV
  
  =item CSV_TYPE_PV
  
  Set field type to string.
  
  =back
  
  =head2 fields
  
   @columns = $csv->fields ();
  
  This method returns the input to   L</combine>  or the resultant decomposed
  fields of a successful L</parse>, whichever was called more recently.
  
  Note that the return value is undefined after using L</getline>, which does
  not fill the data structures returned by L</parse>.
  
  =head2 meta_info
  
   @flags = $csv->meta_info ();
  
  This method returns the "flags" of the input to L</combine> or the flags of
  the resultant  decomposed fields of  L</parse>,   whichever was called more
  recently.
  
  For each field,  a meta_info field will hold  flags that  inform  something
  about  the  field  returned  by  the  L</fields>  method or  passed to  the
  L</combine> method. The flags are bit-wise-C<or>'d like:
  
  =over 2
  
  =item C<0x0001>
  
  =item C<CSV_FLAGS_IS_QUOTED>
  
  The field was quoted.
  
  =item C<0x0002>
  
  =item C<CSV_FLAGS_IS_BINARY>
  
  The field was binary.
  
  =item C<0x0004>
  
  =item C<CSV_FLAGS_ERROR_IN_FIELD>
  
  The field was invalid.
  
  Currently only used when C<allow_loose_quotes> is active.
  
  =item C<0x0010>
  
  =item C<CSV_FLAGS_IS_MISSING>
  
  The field was missing.
  
  =back
  
  See the C<is_***> methods below.
  
  =head2 is_quoted
  
   my $quoted = $csv->is_quoted ($column_idx);
  
  where  C<$column_idx> is the  (zero-based)  index of the column in the last
  result of L</parse>.
  
  This returns a true value  if the data in the indicated column was enclosed
  in L<C<quote_char>|/quote_char> quotes.  This might be important for fields
  where content C<,20070108,> is to be treated as a numeric value,  and where
  C<,"20070108",> is explicitly marked as character string data.
  
  This method is only valid when L</keep_meta_info> is set to a true value.
  
  =head2 is_binary
  
   my $binary = $csv->is_binary ($column_idx);
  
  where  C<$column_idx> is the  (zero-based)  index of the column in the last
  result of L</parse>.
  
  This returns a true value if the data in the indicated column contained any
  byte in the range C<[\x00-\x08,\x10-\x1F,\x7F-\xFF]>.
  
  This method is only valid when L</keep_meta_info> is set to a true value.
  
  =head2 is_missing
  
   my $missing = $csv->is_missing ($column_idx);
  
  where  C<$column_idx> is the  (zero-based)  index of the column in the last
  result of L</getline_hr>.
  
   $csv->keep_meta_info (1);
   while (my $hr = $csv->getline_hr ($fh)) {
       $csv->is_missing (0) and next; # This was an empty line
       }
  
  When using  L</getline_hr>,  it is impossible to tell if the  parsed fields
  are C<undef> because they where not filled in the C<CSV> stream  or because
  they were not read at all, as B<all> the fields defined by L</column_names>
  are set in the hash-ref.    If you still need to know if all fields in each
  row are provided, you should enable L<C<keep_meta_info>|/keep_meta_info> so
  you can check the flags.
  
  If  L<C<keep_meta_info>|/keep_meta_info>  is C<false>,  C<is_missing>  will
  always return C<undef>, regardless of C<$column_idx> being valid or not. If
  this attribute is C<true> it will return either C<0> (the field is present)
  or C<1> (the field is missing).
  
  A special case is the empty line.  If the line is completely empty -  after
  dealing with the flags - this is still a valid CSV line:  it is a record of
  just one single empty field. However, if C<keep_meta_info> is set, invoking
  C<is_missing> with index C<0> will now return true.
  
  =head2 status
  
   $status = $csv->status ();
  
  This method returns the status of the last invoked L</combine> or L</parse>
  call. Status is success (true: C<1>) or failure (false: C<undef> or C<0>).
  
  Note that as this only keeps track of the status of above mentioned methods,
  you are probably looking for L<C<error_diag>|/error_diag> instead.
  
  =head2 error_input
  
   $bad_argument = $csv->error_input ();
  
  This method returns the erroneous argument (if it exists) of L</combine> or
  L</parse>,  whichever was called more recently.  If the last invocation was
  successful, C<error_input> will return C<undef>.
  
  Depending on the type of error, it I<might> also hold the data for the last
  error-input of L</getline>.
  
  =head2 error_diag
  
   Text::CSV_PP->error_diag ();
   $csv->error_diag ();
   $error_code               = 0  + $csv->error_diag ();
   $error_str                = "" . $csv->error_diag ();
   ($cde, $str, $pos, $rec, $fld) = $csv->error_diag ();
  
  If (and only if) an error occurred,  this function returns  the diagnostics
  of that error.
  
  If called in void context,  this will print the internal error code and the
  associated error message to STDERR.
  
  If called in list context,  this will return  the error code  and the error
  message in that order.  If the last error was from parsing, the rest of the
  values returned are a best guess at the location  within the line  that was
  being parsed. Their values are 1-based.  The position currently is index of
  the byte at which the parsing failed in the current record. It might change
  to be the index of the current character in a later release. The records is
  the index of the record parsed by the csv instance. The field number is the
  index of the field the parser thinks it is currently  trying to  parse. See
  F<examples/csv-check> for how this can be used.
  
  If called in  scalar context,  it will return  the diagnostics  in a single
  scalar, a-la C<$!>.  It will contain the error code in numeric context, and
  the diagnostics message in string context.
  
  When called as a class method or a  direct function call,  the  diagnostics
  are that of the last L</new> call.
  
  =head2 record_number
  
   $recno = $csv->record_number ();
  
  Returns the records parsed by this csv instance.  This value should be more
  accurate than C<$.> when embedded newlines come in play. Records written by
  this instance are not counted.
  
  =head2 SetDiag
  
   $csv->SetDiag (0);
  
  Use to reset the diagnostics if you are dealing with errors.
  
  =head1 FUNCTIONS
  
  This section is also taken from Text::CSV_XS.
  
  =head2 csv
  
  This function is not exported by default and should be explicitly requested:
  
   use Text::CSV_PP qw( csv );
  
  This is a high-level function that aims at simple (user) interfaces.  This
  can be used to read/parse a C<CSV> file or stream (the default behavior) or
  to produce a file or write to a stream (define the  C<out>  attribute).  It
  returns an array- or hash-reference on parsing (or C<undef> on fail) or the
  numeric value of  L</error_diag>  on writing.  When this function fails you
  can get to the error using the class call to L</error_diag>
  
   my $aoa = csv (in => "test.csv") or
       die Text::CSV_PP->error_diag;
  
  This function takes the arguments as key-value pairs. This can be passed as
  a list or as an anonymous hash:
  
   my $aoa = csv (  in => "test.csv", sep_char => ";");
   my $aoh = csv ({ in => $fh, headers => "auto" });
  
  The arguments passed consist of two parts:  the arguments to L</csv> itself
  and the optional attributes to the  C<CSV>  object used inside the function
  as enumerated and explained in L</new>.
  
  If not overridden, the default option used for CSV is
  
   auto_diag   => 1
   escape_null => 0
  
  The option that is always set and cannot be altered is
  
   binary      => 1
  
  As this function will likely be used in one-liners,  it allows  C<quote> to
  be abbreviated as C<quo>,  and  C<escape_char> to be abbreviated as  C<esc>
  or C<escape>.
  
  Alternative invocations:
  
   my $aoa = Text::CSV_PP::csv (in => "file.csv");
  
   my $csv = Text::CSV_PP->new ();
   my $aoa = $csv->csv (in => "file.csv");
  
  In the latter case, the object attributes are used from the existing object
  and the attribute arguments in the function call are ignored:
  
   my $csv = Text::CSV_PP->new ({ sep_char => ";" });
   my $aoh = $csv->csv (in => "file.csv", bom => 1);
  
  will parse using C<;> as C<sep_char>, not C<,>.
  
  =head3 in
  
  Used to specify the source.  C<in> can be a file name (e.g. C<"file.csv">),
  which will be  opened for reading  and closed when finished,  a file handle
  (e.g.  C<$fh> or C<FH>),  a reference to a glob (e.g. C<\*ARGV>),  the glob
  itself (e.g. C<*STDIN>), or a reference to a scalar (e.g. C<\q{1,2,"csv"}>).
  
  When used with L</out>, C<in> should be a reference to a CSV structure (AoA
  or AoH)  or a CODE-ref that returns an array-reference or a hash-reference.
  The code-ref will be invoked with no arguments.
  
   my $aoa = csv (in => "file.csv");
  
   open my $fh, "<", "file.csv";
   my $aoa = csv (in => $fh);
  
   my $csv = [ [qw( Foo Bar )], [ 1, 2 ], [ 2, 3 ]];
   my $err = csv (in => $csv, out => "file.csv");
  
  If called in void context without the L</out> attribute, the resulting ref
  will be used as input to a subsequent call to csv:
  
   csv (in => "file.csv", filter => { 2 => sub { length > 2 }})
  
  will be a shortcut to
  
   csv (in => csv (in => "file.csv", filter => { 2 => sub { length > 2 }}))
  
  where, in the absence of the C<out> attribute, this is a shortcut to
  
   csv (in  => csv (in => "file.csv", filter => { 2 => sub { length > 2 }}),
        out => *STDOUT)
  
  =head3 out
  
   csv (in => $aoa, out => "file.csv");
   csv (in => $aoa, out => $fh);
   csv (in => $aoa, out =>   STDOUT);
   csv (in => $aoa, out =>  *STDOUT);
   csv (in => $aoa, out => \*STDOUT);
   csv (in => $aoa, out => \my $data);
   csv (in => $aoa, out =>  undef);
   csv (in => $aoa, out => \"skip");
  
   csv (in => $fh,  out => \@aoa);
   csv (in => $fh,  out => \@aoh, bom => 1);
   csv (in => $fh,  out => \%hsh, key => "key");
  
  In output mode, the default CSV options when producing CSV are
  
   eol       => "\r\n"
  
  The L</fragment> attribute is ignored in output mode.
  
  C<out> can be a file name  (e.g.  C<"file.csv">),  which will be opened for
  writing and closed when finished,  a file handle (e.g. C<$fh> or C<FH>),  a
  reference to a glob (e.g. C<\*STDOUT>),  the glob itself (e.g. C<*STDOUT>),
  or a reference to a scalar (e.g. C<\my $data>).
  
   csv (in => sub { $sth->fetch },            out => "dump.csv");
   csv (in => sub { $sth->fetchrow_hashref }, out => "dump.csv",
        headers => $sth->{NAME_lc});
  
  When a code-ref is used for C<in>, the output is generated  per invocation,
  so no buffering is involved. This implies that there is no size restriction
  on the number of records. The C<csv> function ends when the coderef returns
  a false value.
  
  If C<out> is set to a reference of the literal string C<"skip">, the output
  will be suppressed completely,  which might be useful in combination with a
  filter for side effects only.
  
   my %cache;
   csv (in    => "dump.csv",
        out   => \"skip",
        on_in => sub { $cache{$_[1][1]}++ });
  
  Currently,  setting C<out> to any false value  (C<undef>, C<"">, 0) will be
  equivalent to C<\"skip">.
  
  If the C<in> argument point to something to parse, and the C<out> is set to
  a reference to an C<ARRAY> or a C<HASH>, the output is appended to the data
  in the existing reference. The result of the parse should match what exists
  in the reference passed. This might come handy when you have to parse a set
  of files with similar content (like data stored per period) and you want to
  collect that into a single data structure:
  
   my %hash;
   csv (in => $_, out => \%hash, key => "id") for sort glob "foo-[0-9]*.csv";
  
   my @list; # List of arrays
   csv (in => $_, out => \@list)              for sort glob "foo-[0-9]*.csv";
  
   my @list; # List of hashes
   csv (in => $_, out => \@list, bom => 1)    for sort glob "foo-[0-9]*.csv";
  
  =head3 encoding
  
  If passed,  it should be an encoding accepted by the  C<:encoding()> option
  to C<open>. There is no default value. This attribute does not work in perl
  5.6.x.  C<encoding> can be abbreviated to C<enc> for ease of use in command
  line invocations.
  
  If C<encoding> is set to the literal value C<"auto">, the method L</header>
  will be invoked on the opened stream to check if there is a BOM and set the
  encoding accordingly.   This is equal to passing a true value in the option
  L<C<detect_bom>|/detect_bom>.
  
  Encodings can be stacked, as supported by C<binmode>:
  
   # Using PerlIO::via::gzip
   csv (in       => \@csv,
        out      => "test.csv:via.gz",
        encoding => ":via(gzip):encoding(utf-8)",
        );
   $aoa = csv (in => "test.csv:via.gz",  encoding => ":via(gzip)");
  
   # Using PerlIO::gzip
   csv (in       => \@csv,
        out      => "test.csv:via.gz",
        encoding => ":gzip:encoding(utf-8)",
        );
   $aoa = csv (in => "test.csv:gzip.gz", encoding => ":gzip");
  
  =head3 detect_bom
  
  If  C<detect_bom>  is given, the method  L</header>  will be invoked on the
  opened stream to check if there is a BOM and set the encoding accordingly.
  
  C<detect_bom> can be abbreviated to C<bom>.
  
  This is the same as setting L<C<encoding>|/encoding> to C<"auto">.
  
  Note that as the method  L</header> is invoked,  its default is to also set
  the headers.
  
  =head3 headers
  
  If this attribute is not given, the default behavior is to produce an array
  of arrays.
  
  If C<headers> is supplied,  it should be an anonymous list of column names,
  an anonymous hashref, a coderef, or a literal flag:  C<auto>, C<lc>, C<uc>,
  or C<skip>.
  
  =over 2
  
  =item skip
  
  When C<skip> is used, the header will not be included in the output.
  
   my $aoa = csv (in => $fh, headers => "skip");
  
  C<skip> is invalid/ignored in combinations with L<C<detect_bom>|/detect_bom>.
  
  =item auto
  
  If C<auto> is used, the first line of the C<CSV> source will be read as the
  list of field headers and used to produce an array of hashes.
  
   my $aoh = csv (in => $fh, headers => "auto");
  
  =item lc
  
  If C<lc> is used,  the first line of the  C<CSV> source will be read as the
  list of field headers mapped to  lower case and used to produce an array of
  hashes. This is a variation of C<auto>.
  
   my $aoh = csv (in => $fh, headers => "lc");
  
  =item uc
  
  If C<uc> is used,  the first line of the  C<CSV> source will be read as the
  list of field headers mapped to  upper case and used to produce an array of
  hashes. This is a variation of C<auto>.
  
   my $aoh = csv (in => $fh, headers => "uc");
  
  =item CODE
  
  If a coderef is used,  the first line of the  C<CSV> source will be read as
  the list of mangled field headers in which each field is passed as the only
  argument to the coderef. This list is used to produce an array of hashes.
  
   my $aoh = csv (in      => $fh,
                  headers => sub { lc ($_[0]) =~ s/kode/code/gr });
  
  this example is a variation of using C<lc> where all occurrences of C<kode>
  are replaced with C<code>.
  
  =item ARRAY
  
  If  C<headers>  is an anonymous list,  the entries in the list will be used
  as field names. The first line is considered data instead of headers.
  
   my $aoh = csv (in => $fh, headers => [qw( Foo Bar )]);
   csv (in => $aoa, out => $fh, headers => [qw( code description price )]);
  
  =item HASH
  
  If C<headers> is a hash reference, this implies C<auto>, but header fields
  that exist as key in the hashref will be replaced by the value for that
  key. Given a CSV file like
  
   post-kode,city,name,id number,fubble
   1234AA,Duckstad,Donald,13,"X313DF"
  
  using
  
   csv (headers => { "post-kode" => "pc", "id number" => "ID" }, ...
  
  will return an entry like
  
   { pc     => "1234AA",
     city   => "Duckstad",
     name   => "Donald",
     ID     => "13",
     fubble => "X313DF",
     }
  
  =back
  
  See also L<C<munge_column_names>|/munge_column_names> and
  L<C<set_column_names>|/set_column_names>.
  
  =head3 munge_column_names
  
  If C<munge_column_names> is set,  the method  L</header>  is invoked on the
  opened stream with all matching arguments to detect and set the headers.
  
  C<munge_column_names> can be abbreviated to C<munge>.
  
  =head3 key
  
  If passed,  will default  L<C<headers>|/headers>  to C<"auto"> and return a
  hashref instead of an array of hashes. Allowed values are simple scalars or
  array-references where the first element is the joiner and the rest are the
  fields to join to combine the key.
  
   my $ref = csv (in => "test.csv", key => "code");
   my $ref = csv (in => "test.csv", key => [ ":" => "code", "color" ]);
  
  with test.csv like
  
   code,product,price,color
   1,pc,850,gray
   2,keyboard,12,white
   3,mouse,5,black
  
  the first example will return
  
    { 1   => {
          code    => 1,
          color   => 'gray',
          price   => 850,
          product => 'pc'
          },
      2   => {
          code    => 2,
          color   => 'white',
          price   => 12,
          product => 'keyboard'
          },
      3   => {
          code    => 3,
          color   => 'black',
          price   => 5,
          product => 'mouse'
          }
      }
  
  the second example will return
  
    { "1:gray"    => {
          code    => 1,
          color   => 'gray',
          price   => 850,
          product => 'pc'
          },
      "2:white"   => {
          code    => 2,
          color   => 'white',
          price   => 12,
          product => 'keyboard'
          },
      "3:black"   => {
          code    => 3,
          color   => 'black',
          price   => 5,
          product => 'mouse'
          }
      }
  
  The C<key> attribute can be combined with L<C<headers>|/headers> for C<CSV>
  date that has no header line, like
  
   my $ref = csv (
       in      => "foo.csv",
       headers => [qw( c_foo foo bar description stock )],
       key     =>     "c_foo",
       );
  
  =head3 value
  
  Used to create key-value hashes.
  
  Only allowed when C<key> is valid. A C<value> can be either a single column
  label or an anonymous list of column labels.  In the first case,  the value
  will be a simple scalar value, in the latter case, it will be a hashref.
  
   my $ref = csv (in => "test.csv", key   => "code",
                                    value => "price");
   my $ref = csv (in => "test.csv", key   => "code",
                                    value => [ "product", "price" ]);
   my $ref = csv (in => "test.csv", key   => [ ":" => "code", "color" ],
                                    value => "price");
   my $ref = csv (in => "test.csv", key   => [ ":" => "code", "color" ],
                                    value => [ "product", "price" ]);
  
  with test.csv like
  
   code,product,price,color
   1,pc,850,gray
   2,keyboard,12,white
   3,mouse,5,black
  
  the first example will return
  
    { 1 => 850,
      2 =>  12,
      3 =>   5,
      }
  
  the second example will return
  
    { 1   => {
          price   => 850,
          product => 'pc'
          },
      2   => {
          price   => 12,
          product => 'keyboard'
          },
      3   => {
          price   => 5,
          product => 'mouse'
          }
      }
  
  the third example will return
  
    { "1:gray"    => 850,
      "2:white"   =>  12,
      "3:black"   =>   5,
      }
  
  the fourth example will return
  
    { "1:gray"    => {
          price   => 850,
          product => 'pc'
          },
      "2:white"   => {
          price   => 12,
          product => 'keyboard'
          },
      "3:black"   => {
          price   => 5,
          product => 'mouse'
          }
      }
  
  =head3 keep_headers
  
  When using hashes,  keep the column names into the arrayref passed,  so all
  headers are available after the call in the original order.
  
   my $aoh = csv (in => "file.csv", keep_headers => \my @hdr);
  
  This attribute can be abbreviated to C<kh> or passed as C<keep_column_names>.
  
  This attribute implies a default of C<auto> for the C<headers> attribute.
  
  The headers can also be kept internally to keep stable header order:
  
   csv (in      => csv (in => "file.csv", kh => "internal"),
        out     => "new.csv",
        kh      => "internal");
  
  where C<internal> can also be C<1>, C<yes>, or C<true>. This is similar to
  
   my @h;
   csv (in      => csv (in => "file.csv", kh => \@h),
        out     => "new.csv",
        headers => \@h);
  
  =head3 fragment
  
  Only output the fragment as defined in the L</fragment> method. This option
  is ignored when I<generating> C<CSV>. See L</out>.
  
  Combining all of them could give something like
  
   use Text::CSV_PP qw( csv );
   my $aoh = csv (
       in       => "test.txt",
       encoding => "utf-8",
       headers  => "auto",
       sep_char => "|",
       fragment => "row=3;6-9;15-*",
       );
   say $aoh->[15]{Foo};
  
  =head3 sep_set
  
  If C<sep_set> is set, the method L</header> is invoked on the opened stream
  to detect and set L<C<sep_char>|/sep_char> with the given set.
  
  C<sep_set> can be abbreviated to C<seps>. If neither C<sep_set> not C<seps>
  is given, but C<sep> is defined, C<sep_set> defaults to C<[ sep ]>. This is
  only supported for perl version 5.10 and up.
  
  Note that as the  L</header> method is invoked,  its default is to also set
  the headers.
  
  =head3 set_column_names
  
  If  C<set_column_names> is passed,  the method L</header> is invoked on the
  opened stream with all arguments meant for L</header>.
  
  If C<set_column_names> is passed as a false value, the content of the first
  row is only preserved if the output is AoA:
  
  With an input-file like
  
   bAr,foo
   1,2
   3,4,5
  
  This call
  
   my $aoa = csv (in => $file, set_column_names => 0);
  
  will result in
  
   [[ "bar", "foo"     ],
    [ "1",   "2"       ],
    [ "3",   "4",  "5" ]]
  
  and
  
   my $aoa = csv (in => $file, set_column_names => 0, munge => "none");
  
  will result in
  
   [[ "bAr", "foo"     ],
    [ "1",   "2"       ],
    [ "3",   "4",  "5" ]]
  
  =head2 Callbacks
  
  Callbacks enable actions triggered from the I<inside> of Text::CSV_PP.
  
  While most of what this enables  can easily be done in an  unrolled loop as
  described in the L</SYNOPSIS> callbacks can be used to meet special demands
  or enhance the L</csv> function.
  
  =over 2
  
  =item error
  
   $csv->callbacks (error => sub { $csv->SetDiag (0) });
  
  the C<error>  callback is invoked when an error occurs,  but  I<only>  when
  L</auto_diag> is set to a true value. A callback is invoked with the values
  returned by L</error_diag>:
  
   my ($c, $s);
  
   sub ignore3006 {
       my ($err, $msg, $pos, $recno, $fldno) = @_;
       if ($err == 3006) {
           # ignore this error
           ($c, $s) = (undef, undef);
           Text::CSV_PP->SetDiag (0);
           }
       # Any other error
       return;
       } # ignore3006
  
   $csv->callbacks (error => \&ignore3006);
   $csv->bind_columns (\$c, \$s);
   while ($csv->getline ($fh)) {
       # Error 3006 will not stop the loop
       }
  
  =item after_parse
  
   $csv->callbacks (after_parse => sub { push @{$_[1]}, "NEW" });
   while (my $row = $csv->getline ($fh)) {
       $row->[-1] eq "NEW";
       }
  
  This callback is invoked after parsing with  L</getline>  only if no  error
  occurred.  The callback is invoked with two arguments:   the current C<CSV>
  parser object and an array reference to the fields parsed.
  
  The return code of the callback is ignored  unless it is a reference to the
  string "skip", in which case the record will be skipped in L</getline_all>.
  
   sub add_from_db {
       my ($csv, $row) = @_;
       $sth->execute ($row->[4]);
       push @$row, $sth->fetchrow_array;
       } # add_from_db
  
   my $aoa = csv (in => "file.csv", callbacks => {
       after_parse => \&add_from_db });
  
  This hook can be used for validation:
  
  =over 2
  
  =item FAIL
  
  Die if any of the records does not validate a rule:
  
   after_parse => sub {
       $_[1][4] =~ m/^[0-9]{4}\s?[A-Z]{2}$/ or
           die "5th field does not have a valid Dutch zipcode";
       }
  
  =item DEFAULT
  
  Replace invalid fields with a default value:
  
   after_parse => sub { $_[1][2] =~ m/^\d+$/ or $_[1][2] = 0 }
  
  =item SKIP
  
  Skip records that have invalid fields (only applies to L</getline_all>):
  
   after_parse => sub { $_[1][0] =~ m/^\d+$/ or return \"skip"; }
  
  =back
  
  =item before_print
  
   my $idx = 1;
   $csv->callbacks (before_print => sub { $_[1][0] = $idx++ });
   $csv->print (*STDOUT, [ 0, $_ ]) for @members;
  
  This callback is invoked  before printing with  L</print>  only if no error
  occurred.  The callback is invoked with two arguments:  the current  C<CSV>
  parser object and an array reference to the fields passed.
  
  The return code of the callback is ignored.
  
   sub max_4_fields {
       my ($csv, $row) = @_;
       @$row > 4 and splice @$row, 4;
       } # max_4_fields
  
   csv (in => csv (in => "file.csv"), out => *STDOUT,
       callbacks => { before_print => \&max_4_fields });
  
  This callback is not active for L</combine>.
  
  =back
  
  =head3 Callbacks for csv ()
  
  The L</csv> allows for some callbacks that do not integrate in XS internals
  but only feature the L</csv> function.
  
    csv (in        => "file.csv",
         callbacks => {
             filter       => { 6 => sub { $_ > 15 } },    # first
             after_parse  => sub { say "AFTER PARSE";  }, # first
             after_in     => sub { say "AFTER IN";     }, # second
             on_in        => sub { say "ON IN";        }, # third
             },
         );
  
    csv (in        => $aoh,
         out       => "file.csv",
         callbacks => {
             on_in        => sub { say "ON IN";        }, # first
             before_out   => sub { say "BEFORE OUT";   }, # second
             before_print => sub { say "BEFORE PRINT"; }, # third
             },
         );
  
  =over 2
  
  =item filter
  
  This callback can be used to filter records.  It is called just after a new
  record has been scanned.  The callback accepts a:
  
  =over 2
  
  =item hashref
  
  The keys are the index to the row (the field name or field number, 1-based)
  and the values are subs to return a true or false value.
  
   csv (in => "file.csv", filter => {
              3 => sub { m/a/ },       # third field should contain an "a"
              5 => sub { length > 4 }, # length of the 5th field minimal 5
              });
  
   csv (in => "file.csv", filter => { foo => sub { $_ > 4 }});
  
  If the keys to the filter hash contain any character that is not a digit it
  will also implicitly set L</headers> to C<"auto">  unless  L</headers>  was
  already passed as argument.  When headers are active, returning an array of
  hashes, the filter is not applicable to the header itself.
  
  All sub results should match, as in AND.
  
  The context of the callback sets  C<$_> localized to the field indicated by
  the filter. The two arguments are as with all other callbacks, so the other
  fields in the current row can be seen:
  
   filter => { 3 => sub { $_ > 100 ? $_[1][1] =~ m/A/ : $_[1][6] =~ m/B/ }}
  
  If the context is set to return a list of hashes  (L</headers> is defined),
  the current record will also be available in the localized C<%_>:
  
   filter => { 3 => sub { $_ > 100 && $_{foo} =~ m/A/ && $_{bar} < 1000  }}
  
  If the filter is used to I<alter> the content by changing C<$_>,  make sure
  that the sub returns true in order not to have that record skipped:
  
   filter => { 2 => sub { $_ = uc }}
  
  will upper-case the second field, and then skip it if the resulting content
  evaluates to false. To always accept, end with truth:
  
   filter => { 2 => sub { $_ = uc; 1 }}
  
  =item coderef
  
   csv (in => "file.csv", filter => sub { $n++; 0; });
  
  If the argument to C<filter> is a coderef,  it is an alias or shortcut to a
  filter on column 0:
  
   csv (filter => sub { $n++; 0 });
  
  is equal to
  
   csv (filter => { 0 => sub { $n++; 0 });
  
  =item filter-name
  
   csv (in => "file.csv", filter => "not_blank");
   csv (in => "file.csv", filter => "not_empty");
   csv (in => "file.csv", filter => "filled");
  
  These are predefined filters
  
  Given a file like (line numbers prefixed for doc purpose only):
  
   1:1,2,3
   2:
   3:,
   4:""
   5:,,
   6:, ,
   7:"",
   8:" "
   9:4,5,6
  
  =over 2
  
  =item not_blank
  
  Filter out the blank lines
  
  This filter is a shortcut for
  
   filter => { 0 => sub { @{$_[1]} > 1 or
               defined $_[1][0] && $_[1][0] ne "" } }
  
  Due to the implementation,  it is currently impossible to also filter lines
  that consists only of a quoted empty field. These lines are also considered
  blank lines.
  
  With the given example, lines 2 and 4 will be skipped.
  
  =item not_empty
  
  Filter out lines where all the fields are empty.
  
  This filter is a shortcut for
  
   filter => { 0 => sub { grep { defined && $_ ne "" } @{$_[1]} } }
  
  A space is not regarded being empty, so given the example data, lines 2, 3,
  4, 5, and 7 are skipped.
  
  =item filled
  
  Filter out lines that have no visible data
  
  This filter is a shortcut for
  
   filter => { 0 => sub { grep { defined && m/\S/ } @{$_[1]} } }
  
  This filter rejects all lines that I<not> have at least one field that does
  not evaluate to the empty string.
  
  With the given example data, this filter would skip lines 2 through 8.
  
  =back
  
  =back
  
  One could also use modules like L<Types::Standard>:
  
   use Types::Standard -types;
  
   my $type   = Tuple[Str, Str, Int, Bool, Optional[Num]];
   my $check  = $type->compiled_check;
  
   # filter with compiled check and warnings
   my $aoa = csv (
      in     => \$data,
      filter => {
          0 => sub {
              my $ok = $check->($_[1]) or
                  warn $type->get_message ($_[1]), "\n";
              return $ok;
              },
          },
      );
  
  =item after_in
  
  This callback is invoked for each record after all records have been parsed
  but before returning the reference to the caller.  The hook is invoked with
  two arguments:  the current  C<CSV>  parser object  and a  reference to the
  record.   The reference can be a reference to a  HASH  or a reference to an
  ARRAY as determined by the arguments.
  
  This callback can also be passed as  an attribute without the  C<callbacks>
  wrapper.
  
  =item before_out
  
  This callback is invoked for each record before the record is printed.  The
  hook is invoked with two arguments:  the current C<CSV> parser object and a
  reference to the record.   The reference can be a reference to a  HASH or a
  reference to an ARRAY as determined by the arguments.
  
  This callback can also be passed as an attribute  without the  C<callbacks>
  wrapper.
  
  This callback makes the row available in C<%_> if the row is a hashref.  In
  this case C<%_> is writable and will change the original row.
  
  =item on_in
  
  This callback acts exactly as the L</after_in> or the L</before_out> hooks.
  
  This callback can also be passed as an attribute  without the  C<callbacks>
  wrapper.
  
  This callback makes the row available in C<%_> if the row is a hashref.  In
  this case C<%_> is writable and will change the original row. So e.g. with
  
    my $aoh = csv (
        in      => \"foo\n1\n2\n",
        headers => "auto",
        on_in   => sub { $_{bar} = 2; },
        );
  
  C<$aoh> will be:
  
    [ { foo => 1,
        bar => 2,
        }
      { foo => 2,
        bar => 2,
        }
      ]
  
  =item csv
  
  The I<function>  L</csv> can also be called as a method or with an existing
  Text::CSV_PP object. This could help if the function is to be invoked a lot
  of times and the overhead of creating the object internally over  and  over
  again would be prevented by passing an existing instance.
  
   my $csv = Text::CSV_PP->new ({ binary => 1, auto_diag => 1 });
  
   my $aoa = $csv->csv (in => $fh);
   my $aoa = csv (in => $fh, csv => $csv);
  
  both act the same. Running this 20000 times on a 20 lines CSV file,  showed
  a 53% speedup.
  
  =back
  
  =head1 DIAGNOSTICS
  
  This section is also taken from Text::CSV_XS.
  
  Still under construction ...
  
  If an error occurs,  C<< $csv->error_diag >> can be used to get information
  on the cause of the failure. Note that for speed reasons the internal value
  is never cleared on success,  so using the value returned by L</error_diag>
  in normal cases - when no error occurred - may cause unexpected results.
  
  If the constructor failed, the cause can be found using L</error_diag> as a
  class method, like C<< Text::CSV_PP->error_diag >>.
  
  The C<< $csv->error_diag >> method is automatically invoked upon error when
  the contractor was called with  L<C<auto_diag>|/auto_diag>  set to  C<1> or
  C<2>, or when L<autodie> is in effect.  When set to C<1>, this will cause a
  C<warn> with the error message,  when set to C<2>, it will C<die>. C<2012 -
  EOF> is excluded from L<C<auto_diag>|/auto_diag> reports.
  
  Errors can be (individually) caught using the L</error> callback.
  
  The errors as described below are available. I have tried to make the error
  itself explanatory enough, but more descriptions will be added. For most of
  these errors, the first three capitals describe the error category:
  
  =over 2
  
  =item *
  INI
  
  Initialization error or option conflict.
  
  =item *
  ECR
  
  Carriage-Return related parse error.
  
  =item *
  EOF
  
  End-Of-File related parse error.
  
  =item *
  EIQ
  
  Parse error inside quotation.
  
  =item *
  EIF
  
  Parse error inside field.
  
  =item *
  ECB
  
  Combine error.
  
  =item *
  EHR
  
  HashRef parse related error.
  
  =back
  
  And below should be the complete list of error codes that can be returned:
  
  =over 2
  
  =item *
  1001 "INI - sep_char is equal to quote_char or escape_char"
  
  The  L<separation character|/sep_char>  cannot be equal to  L<the quotation
  character|/quote_char> or to L<the escape character|/escape_char>,  as this
  would invalidate all parsing rules.
  
  =item *
  1002 "INI - allow_whitespace with escape_char or quote_char SP or TAB"
  
  Using the  L<C<allow_whitespace>|/allow_whitespace>  attribute  when either
  L<C<quote_char>|/quote_char> or L<C<escape_char>|/escape_char>  is equal to
  C<SPACE> or C<TAB> is too ambiguous to allow.
  
  =item *
  1003 "INI - \r or \n in main attr not allowed"
  
  Using default L<C<eol>|/eol> characters in either L<C<sep_char>|/sep_char>,
  L<C<quote_char>|/quote_char>,   or  L<C<escape_char>|/escape_char>  is  not
  allowed.
  
  =item *
  1004 "INI - callbacks should be undef or a hashref"
  
  The L<C<callbacks>|/Callbacks>  attribute only allows one to be C<undef> or
  a hash reference.
  
  =item *
  1005 "INI - EOL too long"
  
  The value passed for EOL is exceeding its maximum length (16).
  
  =item *
  1006 "INI - SEP too long"
  
  The value passed for SEP is exceeding its maximum length (16).
  
  =item *
  1007 "INI - QUOTE too long"
  
  The value passed for QUOTE is exceeding its maximum length (16).
  
  =item *
  1008 "INI - SEP undefined"
  
  The value passed for SEP should be defined and not empty.
  
  =item *
  1010 "INI - the header is empty"
  
  The header line parsed in the L</header> is empty.
  
  =item *
  1011 "INI - the header contains more than one valid separator"
  
  The header line parsed in the  L</header>  contains more than one  (unique)
  separator character out of the allowed set of separators.
  
  =item *
  1012 "INI - the header contains an empty field"
  
  The header line parsed in the L</header> contains an empty field.
  
  =item *
  1013 "INI - the header contains nun-unique fields"
  
  The header line parsed in the  L</header>  contains at least  two identical
  fields.
  
  =item *
  1014 "INI - header called on undefined stream"
  
  The header line cannot be parsed from an undefined source.
  
  =item *
  1500 "PRM - Invalid/unsupported argument(s)"
  
  Function or method called with invalid argument(s) or parameter(s).
  
  =item *
  1501 "PRM - The key attribute is passed as an unsupported type"
  
  The C<key> attribute is of an unsupported type.
  
  =item *
  1502 "PRM - The value attribute is passed without the key attribute"
  
  The C<value> attribute is only allowed when a valid key is given.
  
  =item *
  1503 "PRM - The value attribute is passed as an unsupported type"
  
  The C<value> attribute is of an unsupported type.
  
  =item *
  2010 "ECR - QUO char inside quotes followed by CR not part of EOL"
  
  When  L<C<eol>|/eol>  has  been  set  to  anything  but the  default,  like
  C<"\r\t\n">,  and  the  C<"\r">  is  following  the   B<second>   (closing)
  L<C<quote_char>|/quote_char>, where the characters following the C<"\r"> do
  not make up the L<C<eol>|/eol> sequence, this is an error.
  
  =item *
  2011 "ECR - Characters after end of quoted field"
  
  Sequences like C<1,foo,"bar"baz,22,1> are not allowed. C<"bar"> is a quoted
  field and after the closing double-quote, there should be either a new-line
  sequence or a separation character.
  
  =item *
  2012 "EOF - End of data in parsing input stream"
  
  Self-explaining. End-of-file while inside parsing a stream. Can happen only
  when reading from streams with L</getline>,  as using  L</parse> is done on
  strings that are not required to have a trailing L<C<eol>|/eol>.
  
  =item *
  2013 "INI - Specification error for fragments RFC7111"
  
  Invalid specification for URI L</fragment> specification.
  
  =item *
  2014 "ENF - Inconsistent number of fields"
  
  Inconsistent number of fields under strict parsing.
  
  =item *
  2015 "ERW - Empty row"
  
  An empty row was not allowed.
  
  =item *
  2021 "EIQ - NL char inside quotes, binary off"
  
  Sequences like C<1,"foo\nbar",22,1> are allowed only when the binary option
  has been selected with the constructor.
  
  =item *
  2022 "EIQ - CR char inside quotes, binary off"
  
  Sequences like C<1,"foo\rbar",22,1> are allowed only when the binary option
  has been selected with the constructor.
  
  =item *
  2023 "EIQ - QUO character not allowed"
  
  Sequences like C<"foo "bar" baz",qu> and C<2023,",2008-04-05,"Foo, Bar",\n>
  will cause this error.
  
  =item *
  2024 "EIQ - EOF cannot be escaped, not even inside quotes"
  
  The escape character is not allowed as last character in an input stream.
  
  =item *
  2025 "EIQ - Loose unescaped escape"
  
  An escape character should escape only characters that need escaping.
  
  Allowing  the escape  for other characters  is possible  with the attribute
  L</allow_loose_escapes>.
  
  =item *
  2026 "EIQ - Binary character inside quoted field, binary off"
  
  Binary characters are not allowed by default.    Exceptions are fields that
  contain valid UTF-8,  that will automatically be upgraded if the content is
  valid UTF-8. Set L<C<binary>|/binary> to C<1> to accept binary data.
  
  =item *
  2027 "EIQ - Quoted field not terminated"
  
  When parsing a field that started with a quotation character,  the field is
  expected to be closed with a quotation character.   When the parsed line is
  exhausted before the quote is found, that field is not terminated.
  
  =item *
  2030 "EIF - NL char inside unquoted verbatim, binary off"
  
  =item *
  2031 "EIF - CR char is first char of field, not part of EOL"
  
  =item *
  2032 "EIF - CR char inside unquoted, not part of EOL"
  
  =item *
  2034 "EIF - Loose unescaped quote"
  
  =item *
  2035 "EIF - Escaped EOF in unquoted field"
  
  =item *
  2036 "EIF - ESC error"
  
  =item *
  2037 "EIF - Binary character in unquoted field, binary off"
  
  =item *
  2110 "ECB - Binary character in Combine, binary off"
  
  =item *
  2200 "EIO - print to IO failed. See errno"
  
  =item *
  3001 "EHR - Unsupported syntax for column_names ()"
  
  =item *
  3002 "EHR - getline_hr () called before column_names ()"
  
  =item *
  3003 "EHR - bind_columns () and column_names () fields count mismatch"
  
  =item *
  3004 "EHR - bind_columns () only accepts refs to scalars"
  
  =item *
  3006 "EHR - bind_columns () did not pass enough refs for parsed fields"
  
  =item *
  3007 "EHR - bind_columns needs refs to writable scalars"
  
  =item *
  3008 "EHR - unexpected error in bound fields"
  
  =item *
  3009 "EHR - print_hr () called before column_names ()"
  
  =item *
  3010 "EHR - print_hr () called with invalid arguments"
  
  =back
  
  =head1 SEE ALSO
  
  L<Text::CSV_XS>, L<Text::CSV>
  
  Older versions took many regexp from L<http://www.din.or.jp/~ohzaki/perl.htm>
  
  =head1 AUTHOR
  
  Kenichi Ishigaki, E<lt>ishigaki[at]cpan.orgE<gt>
  Makamaka Hannyaharamitu, E<lt>makamaka[at]cpan.orgE<gt>
  
  Text::CSV_XS was written by E<lt>joe[at]ispsoft.deE<gt>
  and maintained by E<lt>h.m.brand[at]xs4all.nlE<gt>.
  
  Text::CSV was written by E<lt>alan[at]mfgrtl.comE<gt>.
  
  =head1 COPYRIGHT AND LICENSE
  
  Copyright 2017- by Kenichi Ishigaki, E<lt>ishigaki[at]cpan.orgE<gt>
  Copyright 2005-2015 by Makamaka Hannyaharamitu, E<lt>makamaka[at]cpan.orgE<gt>
  
  Most of the code and doc is directly taken from the pure perl part of
  Text::CSV_XS.
  
  Copyright (C) 2007-2016 H.Merijn Brand.  All rights reserved.
  Copyright (C) 1998-2001 Jochen Wiedmann. All rights reserved.
  Copyright (C) 1997      Alan Citterman.  All rights reserved.
  
  This library is free software; you can redistribute it and/or modify
  it under the same terms as Perl itself.
  
  =cut
TEXT_CSV_PP

s/^  //mg for values %fatpacked;

my $class = 'FatPacked::'.(0+\%fatpacked);
no strict 'refs';
*{"${class}::files"} = sub { keys %{$_[0]} };

if ($] < 5.008) {
  *{"${class}::INC"} = sub {
    if (my $fat = $_[0]{$_[1]}) {
      my $pos = 0;
      my $last = length $fat;
      return (sub {
        return 0 if $pos == $last;
        my $next = (1 + index $fat, "\n", $pos) || $last;
        $_ .= substr $fat, $pos, $next - $pos;
        $pos = $next;
        return 1;
      });
    }
  };
}

else {
  *{"${class}::INC"} = sub {
    if (my $fat = $_[0]{$_[1]}) {
      open my $fh, '<', \$fat
        or die "FatPacker error loading $_[1] (could be a perl installation issue?)";
      return $fh;
    }
    return;
  };
}

unshift @INC, bless \%fatpacked, $class;
  } # END OF FATPACK CODE


# PODNAME: mtc-bench
#
# ABSTRACT: Benchmark commands using `hyperfine` and `psrecord`. Look into CPU, memory and time.
BEGIN { $ENV{PERL_TEXT_CSV}='Text::CSV_PP'; }


use strict;
use warnings;
use Pod::Usage;
use feature 'say';
use Text::CSV qw/csv/;
use Data::Dump qw/dd pp/;
use Getopt::Long qw(GetOptionsFromArray);
use File::Path qw(make_path);
use POSIX qw(strftime);
use File::Temp qw/ tempdir /;
#
# Get a timestamp in the format "[YYYY-MM-DD HH:MM:SS]"
sub ts {
    my @time = localtime();
    return sprintf("[%04d-%02d-%02d %02d:%02d:%02d]", 
                   $time[5] + 1900, $time[4] + 1, $time[3], 
                   $time[2], $time[1], $time[0]);
}


################################
# Parse command line arguments
################################

# Define default values for variables

my $bench_cmds = [];
my $args = [];
my $help = 0;
my $show_output = 0;
my $verbose = 0;
my $cmd_file = "";
my $global_prep = "";
my $psrec_cmds = [];
my $dry_run = 0;
my $quiet = 0;


Getopt::Long::Configure("pass_through");
GetOptions(
    'help|h' => \$help,
    'show-output|s' => \$show_output,
    'verbose|v' => \$verbose,
    'file|f=s' => \$cmd_file,
    'dry-run|d' => \$dry_run,
    'quiet|q' => \$quiet,
) or pod2usage(2);
Getopt::Long::Configure("no_pass_through");

my $prep_count = 0;
for my $arg (@ARGV) {
    $prep_count++ if $arg eq "--prepare";
}

my $i=1;
if ($prep_count == 1){
    GetOptions( 'prepare|p=s' => \$global_prep) or pod2usage(2);
    $bench_cmds = [];
    for my $arg (@ARGV) {
        push @$bench_cmds, { cmd => $arg, label => $i };
        $i++;
    }
} else {
    while (my $arg = shift @ARGV) {
        if ($arg eq "--prepare"){
           push @$bench_cmds, {
               prepare => shift @ARGV,
               cmd => shift @ARGV,
               label => $i
           };
        } else {
            push @$bench_cmds, {
                cmd => $arg,
               label => $i
            }
        }
        $i++;
    }
}

###########################################################
# Validate and process arguments
###########################################################

if ($help) {
    say STDERR "Usage: $0 [options]";
    say STDERR "Options:";
    say STDERR "  -h, --help            Print this help message";
    say STDERR "  -v, --verbose         Print verbose output";
    say STDERR "  -s, --show-output     Show output of commands";
    say STDERR "  -f, --file            Read commands from file";
    say STDERR "  -d, --dry-run         Just print the command that would be executed";
    say STDERR "  -p, --prepare         Prepare commands to run before benchmarking. See hyperfine --help";
    exit 0;
}

if ($quiet) {
    $verbose = 0;
}

# Check for conflicting options
if ($cmd_file and scalar @$bench_cmds > 0) {
    say STDERR ts(), " Error: Cannot specify both --file ($cmd_file) and commands (@$bench_cmds)";
    exit 1;
}

# Check for missing options
if (not $cmd_file and scalar @$bench_cmds == 0) {
    say STDERR ts(), " Error: Must specify either --file or commands";
    exit 1;
}

# Check for file existence
if ($cmd_file and not -e $cmd_file) {
    say STDERR ts(), " Error: File not found: $cmd_file";
    exit 1;
}

###########################################################
# Read commands
###########################################################

if ($cmd_file) {
    say STDERR ts(), " Reading commands from file: $cmd_file" if $verbose;
    my $csv = csv(in => $cmd_file, headers => 'auto', quote_char => '\\', allow_whitespace => 1);

    my $i=1;
    for my $row (@$csv) {
        push @$bench_cmds, {
            prepare => $row->{prepare},
            cmd => $row->{command},
            label => $row->{label} || $i,
        };
        $i++;
    }
} else {
    say STDERR ts(), " Commands read from command line" if $verbose;
}

###########################################################
# Print benchmark information
###########################################################

my $RESULTS_BASE_DIR = 'mtc-results';
my $TS = strftime("%Y%m%d-%H%M%S", localtime);
my $RES_DIR = $ENV{RES_DIR} || "$RESULTS_BASE_DIR/$TS";
my $WARMUP = $ENV{WARMUP} || 1;
my $RUNS = $ENV{RUNS} || 3;
my $TMP_RES_DIR = tempdir( CLEANUP => 1 );


if (not -d $RES_DIR) {
    make_path($RES_DIR);
}
say STDERR ts(), " Running benchmark with $RUNS repetitions and $WARMUP warm up rounds on these commands:" if ! $quiet;
for (my $i = 0; $i < scalar @$bench_cmds; $i++) {
    my $cmd = $bench_cmds->[$i];
    my $l = $cmd->{label} || $i+1;
    say STDERR "  [$l]: $cmd->{cmd}" if ! $quiet;
}
say STDERR ts(), " Saving results to '$RES_DIR'.\n";

###########################################################
# Cleanup function
###########################################################

my $cleanup_fn_name = "mtc_cleanup_files";
my $cleanup_fn = <<"CLEANUP";
function $cleanup_fn_name() {
    if [[ "$verbose" == true ]]; then
        >&2 echo "Cleaning up..."
    fi

    file=\$(find "$TMP_RES_DIR" -maxdepth 1 -name "*.log" | head -n 1)
    if [[ -z "\$file" ]]; then
        if [[ "$verbose" == true ]]; then
            >&2 echo "  no log file found for cleanup"
        fi
        return
    fi

    label="\${file##*/}"
    label="\${label%.*}"
    if [[ -z "\$label" ]]; then
        >&2 echo "Error: Could not determine label for cleanup"
    fi
    counter=1
    for ext in log png; do
        while [[ -f "$RES_DIR/\$label-\$counter.\$ext" ]]; do
            counter=\$((counter + 1))
        done
        if [[ "$verbose" == true ]]; then
            >&2 echo "  moving $TMP_RES_DIR/\$label.\$ext to $RES_DIR/\$label-\$counter.\$ext"
        fi
        mv "$TMP_RES_DIR/\$label.\$ext" "$RES_DIR/\$label-\$counter.\$ext"
    done
}
CLEANUP


###########################################################
# hyperfine options
###########################################################

my $hf_flags = "";

$hf_flags .= "--show-output" if ($show_output);
$hf_flags .= " --prepare '$global_prep'" if ($global_prep);
$hf_flags .= " --shell=bash --runs $RUNS --warmup $WARMUP";
$hf_flags .= " --export-json $RES_DIR/hyperfine.json";
$hf_flags .= " --export-csv $RES_DIR/hyperfine.csv";
$hf_flags .= " --export-markdown $RES_DIR/hyperfine.md";
$hf_flags .= " --export-asciidoc $RES_DIR/hyperfine.txt";

if ($verbose) {
    say STDERR ts(), " hyperfine flags:\n\t". $hf_flags;
}

###########################################################
# Run hyperfine
###########################################################

my $interval = 0.1;

my $hf_cmds = [];
for my $cmd (@$bench_cmds) {
    my $psr_cmd = "psrecord --interval $interval  ";
    $psr_cmd .= "--plot $TMP_RES_DIR/$cmd->{label}.png ";
    $psr_cmd .= "--log $TMP_RES_DIR/$cmd->{label}.log ";
    $psr_cmd .= "--include-children ";
    $psr_cmd .= "\"$cmd->{cmd}\"";

    $cmd->{psrec_cmd} = $psr_cmd;

    if ($cmd->{prepare}) {
        push @$hf_cmds, " --prepare '$cleanup_fn_name && $cmd->{prepare}'  '$psr_cmd'";
    } else {
        push @$hf_cmds, " '$cmd->{cmd}'";
    }
}

my $hf_cmd = "$cleanup_fn\n";
$hf_cmd .= "export -f $cleanup_fn_name\n";
$hf_cmd .= "hyperfine $hf_flags ".join(" ",  @$hf_cmds);
$hf_cmd .= "\n$cleanup_fn_name\n";
$hf_cmd .= ">&2 echo -e \"\nDone. Results saved to '$RES_DIR'.\"";

if ($dry_run){
    say ts(), ' ', $hf_cmd;
exit 0;
} elsif ($verbose) {
    say STDERR ts(), " COMMAND:\n\t$hf_cmd";
}

exec $hf_cmd;




__END__
 
=head1 NAME