factor/basis/io/encodings/chinese/chinese.factor

134 lines
3.9 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 values io.encodings.ascii ascii io.files biassocs math.order
combinators.short-circuit io.binary ;
IN: io.encodings.chinese
SINGLETON: gb18030
<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
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 ]
[ "bLast" attr b>byte-array ]
} 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 | mapping [ H{ } clone ] ranges [ V{ } clone ] |
[
dup contained? [
dup name>> main>> {
{ "range" [ ranges add-range ] }
{ "a" [ mapping add-mapping ] }
[ 2drop ]
} case
] [ drop ] if
] each-element mapping ranges
] ;
! 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 * + ;
: unlinear ( num -- bytes )
B{ HEX: 81 HEX: 30 HEX: 81 HEX: 30 } linear -
10 /mod swap [ HEX: 30 + ] dip
126 /mod swap [ HEX: 81 + ] dip
10 /mod swap [ HEX: 30 + ] dip
HEX: 81 +
B{ } 4sequence 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>> linear ] [ blast>> linear ] [ ] >interval-map-by ;
VALUE: gb>u
VALUE: u>gb
VALUE: mapping
"resource:basis/io/encodings/chinese/gb-18030-2000.xml"
ascii <file-reader> xml>gb-data
[ ranges-u>gb to: u>gb ] [ ranges-gb>u to: gb>u ] bi
>biassoc to: mapping
: lookup-range ( char -- byte-array )
dup u>gb interval-at [
[ ufirst>> - ] [ bfirst>> linear ] bi + unlinear
] [ encode-error ] if* ;
M: gb18030 encode-char ( char stream encoding -- )
drop [
dup mapping at
[ ] [ lookup-range ] ?if
] dip stream-write ;
: second-byte? ( ch -- ? ) ! of a double-byte character
{ [ HEX: 40 HEX: 7E between? ] [ HEX: 80 HEX: fe between? ] } 1|| ;
: quad-1/3? ( ch -- ? ) HEX: 81 HEX: fe between? ;
: quad-2/4? ( ch -- ? ) HEX: 30 HEX: 39 between? ;
: last-bytes? ( byte-array -- ? )
{ [ length 2 = ] [ first quad-1/3? ] [ second quad-2/4? ] } 1&& ;
: decode-quad ( byte-array -- char )
dup mapping value-at [ ] [
linear dup gb>u interval-at [
[ bfirst>> linear - ] [ ufirst>> ] bi +
] [ drop replacement-char ] if*
] ?if ;
: four-byte ( stream byte1 byte2 -- char )
rot 2 swap stream-read dup last-bytes?
[ first2 B{ } 4sequence decode-quad ]
[ 3drop replacement-char ] if ;
: two-byte ( stream byte -- char )
over stream-read1 {
{ [ dup not ] [ 3drop replacement-char ] }
{ [ dup second-byte? ] [ B{ } 2sequence mapping 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 1array B{ } like mapping value-at ] }
{ [ dup quad-1/3? ] [ two-byte ] }
[ 2drop replacement-char ]
} cond ;