dc.dc

# MACROS

# The following macro prints "Fizz" (without a newline) and writes 1 to register
# X. We store the macro in register A.
[[Fizz] P 1 sX] sA
# This macro prints "Buzz" (without a newline) and writes 1 to register X. We
# store it in register B.
[[Buzz] P 1 sX] sB
# This macro prints the number on the top of the stack with a newline. We store
# it in register C.
[p] sC
# This macro prints a newline. We store it in register D.
[[
] P] sD

# MAIN PROGRAM

# We push the current position to the stack. It doesn't have a name, but in the
# comments we'll call it i.
1

# Here's the main run loop, which will be written to register F:
[
# Register X tells us if we've printed something for the current iteration. We
# haven't yet, so we write 0 to register X.
0 sX
# Calculate i % 3. If it's 0, invoke the macro in register A.
d 3 % 0 =A
# Calculate i % 5. If it's 0, invoke the macro in register B.
d 5 % 0 =B
# If one or both of the macros was invoked, then register X is now 1. If it's
# still 0, then nothing has been printed and we need to print i.
# Read register X. If it's 0, invoke register C. If it's 1, invoke register D.
lX 0 =C
lX 1 =D
# Increment i by 1.
1 +
# If i != 101, invoke the macro in register E (which is this one).
d 101 >E
] d sE x