第17章 2-4节翻译完毕

.gitignore

@@ -6,3 +6,4 @@ _build/*
 *.hi
 *.*~
 .DS_Store
+*.exe

code/ch17/Enum1.hs

@@ -0,0 +1,7 @@
+-- file: ch17/Enum1.hs
+{-# LANGUAGE CPP #-}
+
+#define N 16
+
+main = print [ 1 .. N ]
+

code/ch17/PCRE-compile.hs

@@ -0,0 +1,31 @@
+-- file ch17/PCRE-compile.hs
+
+import Foreign hiding (unsafePerformIO)
+import Foreign.C.Types
+import Foreign.C.String
+import Data.ByteString hiding (pack)
+import System.IO.Unsafe (unsafePerformIO)
+
+import Regex
+
+foreign import ccall unsafe "pcre.h pcre_compile"
+    c_pcre_compile  :: CString
+                    -> PCREOption
+                    -> Ptr CString
+                    -> Ptr CInt
+                    -> Ptr Word8
+                    -> IO (Ptr PCRE)
+
+compile :: ByteString -> [PCREOption] -> Either String Regex
+compile str flags = unsafePerformIO $
+  useAsCString str $ \pattern -> do
+    alloca $ \errptr       -> do
+    alloca $ \erroffset    -> do
+        pcre_ptr <- c_pcre_compile pattern (combineOptions flags) errptr erroffset nullPtr
+        if pcre_ptr == nullPtr
+            then do
+                err <- peekCString =<< peek errptr
+                return (Left err)
+            else do
+                reg <- newForeignPtr finalizerFree pcre_ptr -- release with free()
+                return (Right (Regex reg str))

code/ch17/PCRE-compile0.hs

@@ -0,0 +1,17 @@
+-- file ch17/PCRE-compile0.hs
+
+import Foreign
+import Foreign.C.Types
+import Foreign.C.String
+import Regex hiding (PCRE)
+
+type PCRE = ()
+
+foreign import ccall unsafe "pcre.h pcre_compile"
+    c_pcre_compile  :: CString
+                    -> PCREOption
+                    -> Ptr CString
+                    -> Ptr CInt
+                    -> Ptr Word8
+                    -> IO (Ptr PCRE)
+

code/ch17/PCRE-nullary.hs

@@ -0,0 +1,2 @@
+-- file ch17/PCRE-nullary.hs
+data PCRE

code/ch17/Regex.hsc

@@ -0,0 +1,74 @@
+-- file: ch17/Regex.hsc
+{-# LANGUAGE CPP, ForeignFunctionInterface #-}
+
+module Regex where
+
+import Foreign
+import Foreign.C.Types
+import Data.ByteString (ByteString)
+
+#include <pcre.h>
+
+-- | A type for PCRE compile-time options. These are newtyped CInts,
+-- which can be bitwise-or'd together, using '(Data.Bits..|.)'
+--
+newtype PCREOption = PCREOption { unPCREOption :: CInt }
+    deriving (Eq,Show)
+
+
+-- PCRE compile options
+#{enum PCREOption, PCREOption
+  , caseless             = PCRE_CASELESS
+  , dollar_endonly       = PCRE_DOLLAR_ENDONLY
+  , dotall               = PCRE_DOTALL
+  , dupnames             = PCRE_DUPNAMES
+  , extended             = PCRE_EXTENDED
+  , extra                = PCRE_EXTRA
+  , firstline            = PCRE_FIRSTLINE
+  , multiline            = PCRE_MULTILINE
+  , newline_cr           = PCRE_NEWLINE_CR
+  , newline_crlf         = PCRE_NEWLINE_CRLF
+  , newline_lf           = PCRE_NEWLINE_LF
+  , no_auto_capture      = PCRE_NO_AUTO_CAPTURE
+  , ungreedy             = PCRE_UNGREEDY
+  }
+
+-- | Combine a list of options into a single option, using bitwise (.|.)
+combineOptions :: [PCREOption] -> PCREOption
+combineOptions = PCREOption . foldr ((.|.) . unPCREOption) 0
+
+data PCRE
+
+data Regex = Regex !(ForeignPtr PCRE)
+                   !ByteString
+        deriving (Eq, Ord, Show)
+
+newtype PCREInfo = PCREInfo { unPCREInfo :: CInt }
+    deriving (Eq,Show)
+
+#{enum PCREInfo, PCREInfo 
+  , info_options             = PCRE_INFO_OPTIONS
+  , info_size                = PCRE_INFO_SIZE
+  , info_capturecount        = PCRE_INFO_CAPTURECOUNT
+  , info_backrefmax          = PCRE_INFO_BACKREFMAX
+  , info_firstbyte           = PCRE_INFO_FIRSTBYTE
+  , info_firstchar           = PCRE_INFO_FIRSTCHAR
+  , info_firsttable          = PCRE_INFO_FIRSTTABLE
+  , info_lastliteral         = PCRE_INFO_LASTLITERAL
+  , info_nameentrysize       = PCRE_INFO_NAMEENTRYSIZE
+  , info_namecount           = PCRE_INFO_NAMECOUNT
+  , info_nametable           = PCRE_INFO_NAMETABLE
+  , info_studysize           = PCRE_INFO_STUDYSIZE
+  , info_default_tables      = PCRE_INFO_DEFAULT_TABLES
+  , info_okpartial           = PCRE_INFO_OKPARTIAL
+  , info_jchanged            = PCRE_INFO_JCHANGED
+  , info_hascrorlf           = PCRE_INFO_HASCRORLF
+  , info_minlength           = PCRE_INFO_MINLENGTH
+  }
+
+newtype PCREExecOption = PCREExecOption { unPCREExecOption :: CInt }
+    deriving (Eq,Show)
+
+combineExecOptions :: [PCREExecOption] -> PCREExecOption
+combineExecOptions = PCREExecOption . foldr ((.|.) . unPCREExecOption) 0
+

code/ch17/Regex0.hsc

@@ -0,0 +1,25 @@
+-- file: ch17/Regex0.hsc
+{-# LANGUAGE CPP, ForeignFunctionInterface #-}
+
+module Regex where
+
+import Foreign
+import Foreign.C.Types
+
+#include <pcre.h>
+
+-- | A type for PCRE compile-time options. These are newtyped CInts,
+-- which can be bitwise-or'd together, using '(Data.Bits..|.)'
+--
+newtype PCREOption = PCREOption { unPCREOption :: CInt }
+    deriving (Eq,Show)
+
+caseless       :: PCREOption
+caseless       = PCREOption #const PCRE_CASELESS
+
+dollar_endonly :: PCREOption
+dollar_endonly = PCREOption #const PCRE_DOLLAR_ENDONLY
+
+dotall         :: PCREOption
+dotall         = PCREOption #const PCRE_DOTALL
+

code/ch17/RegexExec.hs

@@ -0,0 +1,102 @@
+-- file ch17/RegexExec.hs
+
+import Foreign hiding (unsafePerformIO)
+import Foreign.C.Types
+import Foreign.C.String
+import Data.ByteString hiding (reverse, pack)
+import System.IO.Unsafe (unsafePerformIO)
+import Data.ByteString.Internal (toForeignPtr)
+import Data.ByteString.Unsafe (unsafeDrop, unsafeTake)
+
+import Regex
+
+foreign import ccall unsafe "pcre.h pcre_compile"
+    c_pcre_compile  :: CString
+                    -> PCREOption
+                    -> Ptr CString
+                    -> Ptr CInt
+                    -> Ptr Word8
+                    -> IO (Ptr PCRE)
+
+compile :: ByteString -> [PCREOption] -> Either String Regex
+compile str flags = unsafePerformIO $
+  useAsCString str $ \pattern -> do
+    alloca $ \errptr       -> do
+    alloca $ \erroffset    -> do
+        pcre_ptr <- c_pcre_compile pattern (combineOptions flags) errptr erroffset nullPtr
+        if pcre_ptr == nullPtr
+            then do
+                err <- peekCString =<< peek errptr
+                return (Left err)
+            else do
+                reg <- newForeignPtr finalizerFree pcre_ptr -- release with free()
+                return (Right (Regex reg str))
+
+data PCREExtra
+
+foreign import ccall "pcre.h pcre_exec"
+    c_pcre_exec     :: Ptr PCRE
+                    -> Ptr PCREExtra
+                    -> Ptr Word8
+                    -> CInt
+                    -> CInt
+                    -> PCREExecOption
+                    -> Ptr CInt
+                    -> CInt
+                    -> IO CInt
+
+foreign import ccall "pcre.h pcre_fullinfo"
+    c_pcre_fullinfo :: Ptr PCRE
+                    -> Ptr PCREExtra
+                    -> PCREInfo
+                    -> Ptr a
+                    -> IO CInt
+
+capturedCount :: Ptr PCRE -> IO Int
+capturedCount regex_ptr =
+    alloca $ \n_ptr -> do
+         c_pcre_fullinfo regex_ptr nullPtr info_capturecount n_ptr
+         return . fromIntegral =<< peek (n_ptr :: Ptr CInt)
+
+match :: Regex -> ByteString -> [PCREExecOption] -> Maybe [ByteString]
+match (Regex pcre_fp _) subject os = unsafePerformIO $ do
+  withForeignPtr pcre_fp $ \pcre_ptr -> do
+    n_capt <- capturedCount pcre_ptr
+
+    let ovec_size = (n_capt + 1) * 3
+        ovec_bytes = ovec_size * sizeOf (undefined :: CInt)
+
+    allocaBytes ovec_bytes $ \ovec -> do
+
+        let (str_fp, off, len) = toForeignPtr subject
+        withForeignPtr str_fp $ \cstr -> do
+            r <- c_pcre_exec
+                         pcre_ptr
+                         nullPtr
+                         (cstr `plusPtr` off)
+                         (fromIntegral len)
+                         0
+                         (combineExecOptions os)
+                         ovec
+                         (fromIntegral ovec_size)
+
+            if r < 0
+                then return Nothing
+                else let loop n o acc =
+                            if n == r
+                              then return (Just (reverse acc))
+                              else do
+                                    i <- peekElemOff ovec o
+                                    j <- peekElemOff ovec (o+1)
+                                    let s = substring i j subject
+                                    loop (n+1) (o+2) (s : acc)
+                     in loop 0 0 []
+
+  where
+    substring :: CInt -> CInt -> ByteString -> ByteString
+    substring x y _ | x == y = empty
+    substring a b s = end
+        where
+            start = unsafeDrop (fromIntegral a) s
+            end   = unsafeTake (fromIntegral (b-a)) start
+

code/ch17/SimpleFFI.hs

@@ -0,0 +1,13 @@
+-- file: ch17/SimpleFFI.hs
+{-# LANGUAGE ForeignFunctionInterface #-}
+
+import Foreign
+import Foreign.C.Types
+
+foreign import ccall "math.h sin"
+     c_sin :: CDouble -> CDouble
+
+fastsin :: Double -> Double
+fastsin x = realToFrac (c_sin (realToFrac x))
+
+main = mapM_ (print . fastsin) [0/10, 1/10 .. 10/10]

convention.rst

@@ -162,10 +162,34 @@
 
 功能依赖	functional dependency
 
+第十七章
+--------
+
+产生         yield
+
+终结器       finalizer
+
+可重入       reentrant
+
+编译指示     pragma
+
+解引用       dereference
+
+类型化的     typed
+
+空元         nullary
+
+托管的指针   managed pointer
+
+空结尾       null-terminated
+
+单子化的     monadic
+
+
 第十八章
 ----------
 
-monad变换器   monad transformer
+monad变换器  monad transformer
 
 monad栈      monad transformer stack / monad stack
 

index.rst

@@ -36,6 +36,7 @@ Real World Haskell 中文版
    chp/14
    chp/15
    chp/16
+   chp/17
    chp/18
    chp/19
    chp/20