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Minor performance improvement for io.encodings.chinese: don't call 'linear' all the time

db4
Slava Pestov 2009-02-04 04:58:19 -06:00
parent cb174f0db1
commit 4ee7fb1c30
1 changed files with 17 additions and 17 deletions
basis/io/encodings/chinese

34
basis/io/encodings/chinese/chinese.factor
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@ -17,6 +17,14 @@ gb18030 "GB18030" register-encoding
! 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 )
@ -27,8 +35,8 @@ TUPLE: range ufirst ulast bfirst blast ;
{
[ "uFirst" attr hex> ]
[ "uLast" attr hex> ]
[ "bFirst" attr b>byte-array ]
[ "bLast" attr b>byte-array ]
[ "bFirst" attr b>byte-array linear ]
[ "bLast" attr b>byte-array linear ]
} cleave range boa
] dip push ;
@ -51,21 +59,13 @@ TUPLE: range ufirst ulast bfirst blast ;
] 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
10 /mod HEX: 30 + swap
126 /mod HEX: 81 + swap
10 /mod HEX: 30 + swap
HEX: 81 +
B{ } 4sequence reverse ;
B{ } 4sequence dup reverse-here ;
: >interval-map-by ( start-quot end-quot value-quot seq -- interval-map )
'[ _ [ @ 2array ] _ tri ] { } map>assoc <interval-map> ; inline
@ -74,7 +74,7 @@ TUPLE: range ufirst ulast bfirst blast ;
[ ufirst>> ] [ ulast>> ] [ ] >interval-map-by ;
: ranges-gb>u ( ranges -- interval-map )
[ bfirst>> linear ] [ blast>> linear ] [ ] >interval-map-by ;
[ bfirst>> ] [ blast>> ] [ ] >interval-map-by ;
VALUE: gb>u
VALUE: u>gb
@ -87,7 +87,7 @@ ascii <file-reader> xml>gb-data
: lookup-range ( char -- byte-array )
dup u>gb interval-at [
[ ufirst>> - ] [ bfirst>> linear ] bi + unlinear
[ ufirst>> - ] [ bfirst>> ] bi + unlinear
] [ encode-error ] if* ;
M: gb18030 encode-char ( char stream encoding -- )
@ -109,7 +109,7 @@ M: gb18030 encode-char ( char stream encoding -- )
: decode-quad ( byte-array -- char )
dup mapping value-at [ ] [
linear dup gb>u interval-at [
[ bfirst>> linear - ] [ ufirst>> ] bi +
[ bfirst>> - ] [ ufirst>> ] bi +
] [ drop replacement-char ] if*
] ?if ;