factor/basis/io/encodings/gb18030/gb18030.factor

140 lines
4.0 KiB
Factor

! Copyright (C) 2009 Daniel Ehrenberg
! See http://factorcode.org/license.txt for BSD license.
USING: xml xml.data kernel io io.encodings interval-maps splitting fry
math.parser sequences combinators assocs locals accessors math arrays
byte-arrays ascii io.files biassocs math.order namespaces
combinators.short-circuit io.binary io.encodings.iana ;
FROM: io.encodings.ascii => ascii ;
IN: io.encodings.gb18030
SINGLETON: gb18030
gb18030 "GB18030" register-encoding
<PRIVATE
! GB to mean GB18030 is a terrible abuse of notation
! Resource file from:
! http://source.icu-project.org/repos/icu/data/trunk/charset/data/xml/gb-18030-2000.xml
! Algorithms from:
! http://www-128.ibm.com/developerworks/library/u-china.html
: linear ( bytes -- num )
! This hard-codes bMin and bMax
reverse first4
10 * + 126 * + 10 * + ; foldable
TUPLE: range ufirst ulast bfirst blast ;
: b>byte-array ( string -- byte-array )
" " split [ hex> ] B{ } map-as ;
: add-range ( contained ranges -- )
[
{
[ "uFirst" attr hex> ]
[ "uLast" attr hex> ]
[ "bFirst" attr b>byte-array linear ]
[ "bLast" attr b>byte-array linear ]
} cleave range boa
] dip push ;
: add-mapping ( contained mapping -- )
[
[ "b" attr b>byte-array ]
[ "u" attr hex> ] bi
] dip set-at ;
: xml>gb-data ( stream -- mapping ranges )
[let
H{ } clone :> mapping V{ } clone :> ranges
[
dup contained? [
dup name>> main>> {
{ "range" [ ranges add-range ] }
{ "a" [ mapping add-mapping ] }
[ 2drop ]
} case
] [ drop ] if
] each-element mapping ranges
] ;
: unlinear ( num -- bytes )
B{ 0x81 0x30 0x81 0x30 } linear -
10 /mod 0x30 + swap
126 /mod 0x81 + swap
10 /mod 0x30 + swap
0x81 +
4byte-array reverse! ;
: >interval-map-by ( start-quot end-quot value-quot seq -- interval-map )
'[ _ [ @ 2array ] _ tri ] { } map>assoc <interval-map> ; inline
: ranges-u>gb ( ranges -- interval-map )
[ ufirst>> ] [ ulast>> ] [ ] >interval-map-by ;
: ranges-gb>u ( ranges -- interval-map )
[ bfirst>> ] [ blast>> ] [ ] >interval-map-by ;
SYMBOL: gb>u
SYMBOL: u>gb
SYMBOL: mapping
"vocab:io/encodings/gb18030/gb-18030-2000.xml"
ascii <file-reader> xml>gb-data
[ ranges-u>gb u>gb set-global ] [ ranges-gb>u gb>u set-global ] bi
>biassoc mapping set-global
: lookup-range ( char -- byte-array )
dup u>gb get-global interval-at [
[ ufirst>> - ] [ bfirst>> ] bi + unlinear
] [ encode-error ] if* ;
M: gb18030 encode-char ( char stream encoding -- )
drop [
dup mapping get-global at
[ ] [ lookup-range ] ?if
] dip stream-write ;
: second-byte? ( ch -- ? ) ! of a double-byte character
{ [ 0x40 0x7E between? ] [ 0x80 0xfe between? ] } 1|| ;
: quad-1/3? ( ch -- ? ) 0x81 0xfe between? ;
: quad-2/4? ( ch -- ? ) 0x30 0x39 between? ;
: last-bytes? ( byte-array -- ? )
{ [ length 2 = ] [ first quad-1/3? ] [ second quad-2/4? ] } 1&& ;
: decode-quad ( byte-array -- char )
dup mapping get-global value-at [ ] [
linear dup gb>u get-global interval-at [
[ bfirst>> - ] [ ufirst>> ] bi +
] [ drop replacement-char ] if*
] ?if ;
: four-byte ( stream byte1 byte2 -- char )
rot 2 swap stream-read dup last-bytes?
[ first2 4byte-array decode-quad ]
[ 3drop replacement-char ] if ;
: two-byte ( stream byte -- char )
over stream-read1 {
{ [ dup not ] [ 3drop replacement-char ] }
{ [ dup second-byte? ] [ 2byte-array mapping get-global value-at nip ] }
{ [ dup quad-2/4? ] [ four-byte ] }
[ 3drop replacement-char ]
} cond ;
M: gb18030 decode-char ( stream encoding -- char )
drop dup stream-read1 {
{ [ dup not ] [ 2drop f ] }
{ [ dup ascii? ] [ nip 1byte-array mapping get-global value-at ] }
{ [ dup quad-1/3? ] [ two-byte ] }
[ 2drop replacement-char ]
} cond ;
PRIVATE>