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use combinators.smart for bit-count

db4
Doug Coleman 2009-01-08 18:57:07 -06:00
parent fe92608a1f
commit 932631c901
2 changed files with 13 additions and 7 deletions

4
basis/math/bitwise/bitwise-tests.factor
View File

@ -32,3 +32,7 @@ IN: math.bitwise.tests
[ 8 ] [ 0 3 toggle-bit ] unit-test
[ 0 ] [ 8 3 toggle-bit ] unit-test
[ 4 ] [ BIN: 1010101 bit-count ] unit-test
[ 0 ] [ BIN: 0 bit-count ] unit-test
[ 1 ] [ BIN: 1 bit-count ] unit-test

16
basis/math/bitwise/bitwise.factor
View File

@ -2,7 +2,7 @@
! See http://factorcode.org/license.txt for BSD license.
USING: arrays kernel math math.functions sequences
sequences.private words namespaces macros hints
combinators fry io.binary ;
combinators fry io.binary combinators.smart ;
IN: math.bitwise
! utilities
@ -76,12 +76,14 @@ DEFER: byte-bit-count
GENERIC: (bit-count) ( x -- n )
M: fixnum (bit-count)
{
[ byte-bit-count ]
[ -8 shift byte-bit-count ]
[ -16 shift byte-bit-count ]
[ -24 shift byte-bit-count ]
} cleave + + + ;
[
{
[ byte-bit-count ]
[ -8 shift byte-bit-count ]
[ -16 shift byte-bit-count ]
[ -24 shift byte-bit-count ]
} cleave
] sum-outputs ;
M: bignum (bit-count)
dup 0 = [ drop 0 ] [