factor/basis/bit-arrays/bit-arrays.factor

104 lines
2.7 KiB
Factor

! Copyright (C) 2007, 2011 Slava Pestov.
! See http://factorcode.org/license.txt for BSD license.
USING: accessors alien alien.accessors byte-arrays fry io.binary
kernel kernel.private locals math math.bitwise parser
prettyprint.custom sequences sequences.private ;
IN: bit-arrays
TUPLE: bit-array
{ length array-capacity read-only }
{ underlying byte-array read-only } ;
<PRIVATE
: n>byte ( m -- n ) -3 shift ; inline
: bit/byte ( n -- bit byte ) [ 7 bitand ] [ n>byte ] bi ; inline
: bit-index ( n bit-array -- bit# byte# byte-array )
[ { integer-array-capacity } declare integer>fixnum bit/byte ]
[ underlying>> ] bi* ; inline
: bits>cells ( m -- n ) 31 + -5 shift ; inline
: bits>bytes ( m -- n ) 7 + n>byte ; inline
: (set-bits) ( bit-array n -- )
[ [ length bits>cells ] keep ] dip swap underlying>>
'[ [ _ _ ] dip 4 * set-alien-unsigned-4 ] each-integer ; inline
: zero-end-bits ( bit-array -- bit-array )
! Zero bits after the end.
dup underlying>> [ ] [
[
length 8 * over length -
8 swap - -1 swap shift bitnot
]
[ last bitand ]
[ set-last ]
tri
] if-empty ; inline
:: toggle-bit ( ? n x -- y )
x n ? [ set-bit ] [ clear-bit ] if ; inline
PRIVATE>
ERROR: bad-array-length n ;
: <bit-array> ( n -- bit-array )
dup 0 < [ bad-array-length ] when
dup bits>bytes <byte-array>
bit-array boa ; inline
M: bit-array length length>> ; inline
M: bit-array nth-unsafe
bit-index nth-unsafe swap bit? ; inline
M: bit-array set-nth-unsafe
bit-index [ toggle-bit ] change-nth-unsafe ; inline
GENERIC: clear-bits ( bit-array -- )
M: bit-array clear-bits 0 (set-bits) ; inline
GENERIC: set-bits ( bit-array -- )
M: bit-array set-bits -1 (set-bits) ; inline
M: bit-array clone
[ length>> ] [ underlying>> clone ] bi bit-array boa ; inline
: >bit-array ( seq -- bit-array )
T{ bit-array f 0 B{ } } clone-like ; inline
M: bit-array like drop dup bit-array? [ >bit-array ] unless ; inline
M: bit-array new-sequence drop <bit-array> ; inline
M: bit-array equal?
over bit-array? [ [ underlying>> ] bi@ sequence= ] [ 2drop f ] if ;
M: bit-array resize
dupd [ bits>bytes ] [ underlying>> ] bi*
resize-byte-array bit-array boa zero-end-bits ; inline
M: bit-array byte-length length bits>bytes ; inline
SYNTAX: ?{ \ } [ >bit-array ] parse-literal ;
: integer>bit-array ( n -- bit-array )
dup 0 =
[ <bit-array> ]
[ dup log2 1 + [ nip ] [ bits>bytes >le ] 2bi bit-array boa ] if ;
: bit-array>integer ( bit-array -- n )
underlying>> le> ;
INSTANCE: bit-array sequence
M: bit-array pprint-delims drop \ ?{ \ } ;
M: bit-array >pprint-sequence ;
M: bit-array pprint* pprint-object ;