factor/extra/brainfuck/brainfuck.factor

91 lines
2.2 KiB
Factor

! Copyright (C) 2009 John Benediktsson
! See http://factorcode.org/license.txt for BSD license
USING: accessors assocs command-line fry io io.encodings.binary
io.files io.streams.string kernel macros math namespaces
peg.ebnf prettyprint sequences multiline ;
IN: brainfuck
<PRIVATE
TUPLE: brainfuck pointer memory ;
: <brainfuck> ( -- brainfuck )
0 H{ } clone brainfuck boa ;
: get-memory ( brainfuck -- brainfuck value )
dup [ pointer>> ] [ memory>> ] bi at 0 or ;
: set-memory ( brainfuck value -- brainfuck )
over [ pointer>> ] [ memory>> ] bi set-at ;
: (+) ( brainfuck n -- brainfuck )
[ get-memory ] dip + 255 bitand set-memory ;
: (-) ( brainfuck n -- brainfuck )
[ get-memory ] dip - 255 bitand set-memory ;
: (.) ( brainfuck -- brainfuck )
get-memory write1 ;
: (,) ( brainfuck -- brainfuck )
read1 set-memory ;
: (>) ( brainfuck n -- brainfuck )
'[ _ + ] change-pointer ;
: (<) ( brainfuck n -- brainfuck )
'[ _ - ] change-pointer ;
: (#) ( brainfuck -- brainfuck )
dup
[ "ptr=" write pointer>> pprint ]
[ ",mem=" write memory>> pprint nl ] bi ;
: compose-all ( seq -- quot )
[ ] [ compose ] reduce ;
EBNF: parse-brainfuck [=[
inc-ptr = (">")+ => [[ length '[ _ (>) ] ]]
dec-ptr = ("<")+ => [[ length '[ _ (<) ] ]]
inc-mem = ("+")+ => [[ length '[ _ (+) ] ]]
dec-mem = ("-")+ => [[ length '[ _ (-) ] ]]
output = "." => [[ [ (.) ] ]]
input = "," => [[ [ (,) ] ]]
debug = "#" => [[ [ (#) ] ]]
space = [ \t\n\r]+ => [[ [ ] ]]
unknown = (.) => [[ "Invalid input" throw ]]
ops = inc-ptr|dec-ptr|inc-mem|dec-mem|output|input|debug|space
loop = "[" {loop|ops}+ "]" => [[ second compose-all '[ [ get-memory zero? ] _ until ] ]]
code = (loop|ops|unknown)* => [[ compose-all ]]
]=]
PRIVATE>
MACRO: run-brainfuck ( code -- quot )
parse-brainfuck '[ <brainfuck> @ drop flush ] ;
: get-brainfuck ( code -- result )
[ run-brainfuck ] with-string-writer ; inline
<PRIVATE
: (run-brainfuck) ( code -- )
[ <brainfuck> ] dip parse-brainfuck call( x -- x ) drop flush ;
PRIVATE>
: brainfuck-main ( -- )
command-line get [
contents (run-brainfuck)
] [
[ binary file-contents (run-brainfuck) ] each
] if-empty ;
MAIN: brainfuck-main