factor/basis/io/encodings/utf32/utf32.factor

65 lines
1.3 KiB
Factor

! Copyright (C) 2009 Daniel Ehrenberg.
! See http://factorcode.org/license.txt for BSD license.
USING: math kernel io.encodings combinators io io.encodings.utf16
sequences io.binary io.encodings.iana ;
IN: io.encodings.utf32
SINGLETON: utf32be
utf32be "UTF-32BE" register-encoding
SINGLETON: utf32le
utf32le "UTF-32LE" register-encoding
SINGLETON: utf32
utf32 "UTF-32" register-encoding
<PRIVATE
! Decoding
: char> ( stream encoding quot -- ch )
nip swap 4 swap stream-read dup length {
{ 0 [ 2drop f ] }
{ 4 [ swap call ] }
[ 3drop replacement-char ]
} case ; inline
M: utf32be decode-char
[ be> ] char> ;
M: utf32le decode-char
[ le> ] char> ;
! Encoding
: >char ( char stream encoding quot -- )
nip 4 swap curry dip stream-write ; inline
M: utf32be encode-char
[ >be ] >char ;
M: utf32le encode-char
[ >le ] >char ;
! UTF-32
CONSTANT: bom-le B{ 0xff 0xfe 0 0 }
CONSTANT: bom-be B{ 0 0 0xfe 0xff }
: bom>le/be ( bom -- le/be )
dup bom-le sequence= [ drop utf32le ] [
bom-be sequence= [ utf32be ] [ missing-bom ] if
] if ;
M: utf32 <decoder> ( stream utf32 -- decoder )
drop 4 over stream-read bom>le/be <decoder> ;
M: utf32 <encoder> ( stream utf32 -- encoder )
drop bom-le over stream-write utf32le <encoder> ;
PRIVATE>