factor/basis/endian/endian.factor

77 lines
1.9 KiB
Factor

! Copyright (C) 2009 Doug Coleman.
! See http://factorcode.org/license.txt for BSD license.
USING: alien.c-types alien.data namespaces io.binary fry
kernel math grouping sequences math.bitwise ;
IN: endian
SINGLETONS: big-endian little-endian ;
: compute-native-endianness ( -- class )
1 int <ref> char deref 0 = big-endian little-endian ? ; foldable
SYMBOL: native-endianness
native-endianness [ compute-native-endianness ] initialize
SYMBOL: endianness
endianness [ native-endianness get-global ] initialize
HOOK: >native-endian native-endianness ( obj n -- bytes )
M: big-endian >native-endian >be ;
M: little-endian >native-endian >le ;
HOOK: unsigned-native-endian> native-endianness ( obj -- bytes )
M: big-endian unsigned-native-endian> be> ;
M: little-endian unsigned-native-endian> le> ;
: signed-native-endian> ( obj n -- n' )
[ unsigned-native-endian> ] dip >signed ;
HOOK: >endian endianness ( obj n -- bytes )
M: big-endian >endian >be ;
M: little-endian >endian >le ;
HOOK: endian> endianness ( seq -- n )
M: big-endian endian> be> ;
M: little-endian endian> le> ;
HOOK: unsigned-endian> endianness ( obj -- bytes )
M: big-endian unsigned-endian> be> ;
M: little-endian unsigned-endian> le> ;
: signed-endian> ( obj n -- bytes )
[ unsigned-endian> ] dip >signed ;
: with-endianness ( endian quot -- )
[ endianness ] dip with-variable ; inline
: with-big-endian ( quot -- )
big-endian swap with-endianness ; inline
: with-little-endian ( quot -- )
little-endian swap with-endianness ; inline
: with-native-endian ( quot -- )
\ native-endianness get-global swap with-endianness ; inline
: seq>native-endianness ( seq n -- seq' )
native-endianness get-global dup endianness get = [
2drop
] [
[ [ <groups> ] keep ] dip
little-endian = [
'[ be> _ >le ] map
] [
'[ le> _ >be ] map
] if concat
] if ; inline