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working on lzw compression

db4
Doug Coleman 2009-02-12 22:11:11 -06:00
parent b5cb425708
commit 12ee26566e
1 changed files with 17 additions and 3 deletions
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20
basis/compression/lzw/lzw.factor
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@ -110,9 +110,23 @@ ERROR: not-in-table ;
: lzw-compress-chars ( lzw -- ) : lzw-compress-chars ( lzw -- )
{ {
[ [ clear-code lzw-compress-char ] [ reset-lzw-compress drop ] bi ] ! [ [ clear-code lzw-compress-char ] [ drop ] bi ] ! reset-lzw-compress drop ] bi ]
[
[ clear-code ] dip
[ lzw-bit-width-compress ]
[ output>> write-bits ] bi
]
[ (lzw-compress-chars) ] [ (lzw-compress-chars) ]
[ end-of-information lzw-compress-char ] [
[ k>> ]
[ lzw-bit-width-compress ]
[ output>> write-bits ] tri
]
[
[ end-of-information ] dip
[ lzw-bit-width-compress ]
[ output>> write-bits ] bi
]
[ ] [ ]
} cleave dup end-of-input?>> [ drop ] [ lzw-compress-chars ] if ; } cleave dup end-of-input?>> [ drop ] [ lzw-compress-chars ] if ;
@ -138,7 +152,7 @@ ERROR: not-in-table ;
: add-to-table ( seq lzw -- ) table>> push ; : add-to-table ( seq lzw -- ) table>> push ;
: lzw-read ( lzw -- lzw n ) : lzw-read ( lzw -- lzw n )
[ ] [ lzw-bit-width-uncompress ] [ input>> ] tri read-bits ; [ ] [ lzw-bit-width-uncompress ] [ input>> ] tri read-bits 2drop ;
DEFER: lzw-uncompress-char DEFER: lzw-uncompress-char
: handle-clear-code ( lzw -- ) : handle-clear-code ( lzw -- )