factor/core/collections/bit-arrays.factor

57 lines
1.3 KiB
Factor

! Copyright (C) 2007 Slava Pestov.
! See http://factorcode.org/license.txt for BSD license.
IN: sequences-internals
USING: math alien kernel byte-arrays ;
: n>cell -5 shift 4 * ; inline
: cell/bit ( n alien -- byte bit )
over n>cell alien-unsigned-4 swap 31 bitand ; inline
: set-bit ( ? byte bit -- byte )
2^ rot [ bitor ] [ bitnot bitand ] if ; inline
: bits>bytes 7 + 8 /i ; inline
IN: bit-arrays
USING: sequences ;
TUPLE: bit-array store length ;
M: bit-array underlying bit-array-store ;
M: bit-array set-underlying set-bit-array-store ;
C: bit-array ( len -- bit-array )
[ set-bit-array-length ] 2keep
swap bits>bytes 4 align <byte-array>
over set-bit-array-store ;
M: bit-array length bit-array-length ;
M: bit-array nth-unsafe
underlying cell/bit 2^ bitand 0 > ;
M: bit-array nth bounds-check nth-unsafe ;
M: bit-array set-nth-unsafe
underlying
[ cell/bit set-bit ] 2keep
swap n>cell set-alien-unsigned-4 ;
M: bit-array set-nth bounds-check set-nth-unsafe ;
: clear-bits ( bit-array -- )
underlying [ drop 0 ] inject ;
M: bit-array clone clone-resizable ;
: >bit-array ( seq -- bit-array ) ?{ } clone-like ; inline
M: bit-array like drop dup bit-array? [ >bit-array ] unless ;
M: bit-array new drop <bit-array> ;
M: bit-array equal?
over bit-array? [ sequence= ] [ 2drop f ] if ;