1 ! Copyright (C) 2007, 2011 Slava Pestov.
2 ! See http://factorcode.org/license.txt for BSD license.
3 USING: accessors alien alien.accessors byte-arrays endian
4 kernel kernel.private math math.bitwise parser sequences
5 sequences.private vocabs.loader ;
9 { length array-capacity read-only }
10 { underlying byte-array read-only } ;
14 : n>byte ( m -- n ) -3 shift ; inline
16 : bit/byte ( n -- bit byte ) [ 7 bitand ] [ n>byte ] bi ; inline
18 : bit-index ( n bit-array -- bit# byte# byte-array )
19 [ { integer-array-capacity } declare integer>fixnum bit/byte ]
20 [ underlying>> ] bi* ; inline
22 : bits>cells ( m -- n ) 31 + -5 shift ; inline
24 : bits>bytes ( m -- n ) 7 + n>byte ; inline
26 : (set-bits) ( bit-array n -- )
27 [ [ length bits>cells ] keep ] dip swap underlying>>
28 '[ [ _ _ ] dip 4 * set-alien-unsigned-4 ] each-integer ; inline
30 : zero-end-bits ( bit-array -- bit-array )
31 ! Zero bits after the end.
32 dup underlying>> [ ] [
34 length 8 * over length -
35 8 swap - -1 swap shift bitnot
42 :: toggle-bit ( ? n x -- y )
43 x n ? [ set-bit ] [ clear-bit ] if ; inline
47 ERROR: bad-array-length n ;
49 : <bit-array> ( n -- bit-array )
50 dup 0 < [ bad-array-length ] when
51 dup bits>bytes <byte-array>
52 bit-array boa ; inline
54 M: bit-array length length>> ; inline
56 M: bit-array nth-unsafe
57 bit-index nth-unsafe swap bit? ; inline
59 M: bit-array set-nth-unsafe
60 bit-index [ toggle-bit ] change-nth-unsafe ; inline
62 GENERIC: clear-bits ( bit-array -- )
64 M: bit-array clear-bits 0 (set-bits) ; inline
66 GENERIC: set-bits ( bit-array -- )
68 M: bit-array set-bits -1 (set-bits) ; inline
71 [ length>> ] [ underlying>> clone ] bi bit-array boa ; inline
73 : >bit-array ( seq -- bit-array )
74 T{ bit-array f 0 B{ } } clone-like ; inline
76 M: bit-array like drop dup bit-array? [ >bit-array ] unless ; inline
78 M: bit-array new-sequence drop <bit-array> ; inline
81 over bit-array? [ [ underlying>> ] bi@ sequence= ] [ 2drop f ] if ;
84 dupd [ bits>bytes ] [ underlying>> ] bi*
85 resize-byte-array bit-array boa zero-end-bits ; inline
87 M: bit-array byte-length length bits>bytes ; inline
89 SYNTAX: ?{ \ } [ >bit-array ] parse-literal ;
91 : integer>bit-array ( n -- bit-array )
94 [ dup log2 1 + [ nip ] [ bits>bytes >le ] 2bi bit-array boa ] if ;
96 : bit-array>integer ( bit-array -- n )
99 INSTANCE: bit-array sequence
101 { "bit-arrays" "prettyprint" } "bit-arrays.prettyprint" require-when