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Merge branch 'master' of git://factorcode.org/git/factor

db4
Joe Groff 2009-05-15 15:27:32 -05:00
parent ae5f5553e6 9785cd4c40
commit e7744cfbe3
1 changed files with 9 additions and 6 deletions
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15
basis/bitstreams/bitstreams.factor
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@ -123,7 +123,10 @@ ERROR: not-enough-bits n bit-reader ;
: #bits>#bytes ( #bits -- #bytes ) : #bits>#bytes ( #bits -- #bytes )
8 /mod 0 = [ 1 + ] unless ; inline 8 /mod 0 = [ 1 + ] unless ; inline
:: subseq>bits ( bignum n bs -- bits ) :: subseq>bits-le ( bignum n bs -- bits )
bignum bs bit-pos>> neg shift n bits ;
:: subseq>bits-be ( bignum n bs -- bits )
bignum bignum
8 bs bit-pos>> - n - 8 mod dup 0 < [ 8 + ] when 8 bs bit-pos>> - n - 8 mod dup 0 < [ 8 + ] when
neg shift n bits ; neg shift n bits ;
@ -138,15 +141,15 @@ ERROR: not-enough-bits n bit-reader ;
bs (>>bit-pos) bs (>>bit-pos)
] if ; ] if ;
:: (peek) ( n bs word -- bits ) :: (peek) ( n bs endian> subseq-endian -- bits )
n bs enough-bits? [ n bs not-enough-bits ] unless n bs enough-bits? [ n bs not-enough-bits ] unless
bs [ byte-pos>> ] [ bit-pos>> n + ] bi #bits>#bytes dupd + bs [ byte-pos>> ] [ bit-pos>> n + ] bi #bits>#bytes dupd +
bs bytes>> subseq word execute( seq -- x ) :> bignum bs bytes>> subseq endian> execute( seq -- x ) :> bignum
bignum n bs subseq>bits ; bignum n bs subseq-endian execute( bignum n bs -- bits ) ;
M: lsb0-bit-reader peek ( n bs -- bits ) \ le> (peek) ; M: lsb0-bit-reader peek ( n bs -- bits ) \ le> \ subseq>bits-le (peek) ;
M: msb0-bit-reader peek ( n bs -- bits ) \ be> (peek) ; M: msb0-bit-reader peek ( n bs -- bits ) \ be> \ subseq>bits-be (peek) ;
:: bit-writer-bytes ( writer -- bytes ) :: bit-writer-bytes ( writer -- bytes )
writer widthed>> #bits>> :> n writer widthed>> #bits>> :> n