1 ! Copyright (C) 2007, 2008 Slava Pestov, Doug Coleman.
2 ! See http://factorcode.org/license.txt for BSD license.
3 USING: arrays assocs kernel math sequences accessors
4 math.bits sequences.private words namespaces macros
5 hints combinators fry io.binary combinators.smart ;
9 : clear-bit ( x n -- y ) 2^ bitnot bitand ; inline
10 : set-bit ( x n -- y ) 2^ bitor ; inline
11 : bit-clear? ( x n -- ? ) 2^ bitand 0 = ; inline
12 : unmask ( x n -- ? ) bitnot bitand ; inline
13 : unmask? ( x n -- ? ) unmask 0 > ; inline
14 : mask ( x n -- ? ) bitand ; inline
15 : mask? ( x n -- ? ) mask 0 > ; inline
16 : wrap ( m n -- m' ) 1 - bitand ; inline
17 : bits ( m n -- m' ) 2^ wrap ; inline
18 : mask-bit ( m n -- m' ) 2^ mask ; inline
19 : on-bits ( n -- m ) 2^ 1 - ; inline
20 : toggle-bit ( m n -- m' ) 2^ bitxor ; inline
22 : shift-mod ( n s w -- n )
23 [ shift ] dip 2^ wrap ; inline
25 : bitroll ( x s w -- y )
27 [ shift-mod ] [ [ - ] keep shift-mod ] 3bi bitor ; inline
29 : bitroll-32 ( n s -- n' ) 32 bitroll ; inline
31 : bitroll-64 ( n s -- n' ) 64 bitroll ; inline
34 : w+ ( int int -- int ) + 32 bits ; inline
35 : w- ( int int -- int ) - 32 bits ; inline
36 : w* ( int int -- int ) * 32 bits ; inline
39 : W+ ( int int -- int ) + 64 bits ; inline
40 : W- ( int int -- int ) - 64 bits ; inline
41 : W* ( int int -- int ) * 64 bits ; inline
44 MACRO: flags ( values -- )
45 [ 0 ] [ [ ?execute bitor ] curry compose ] reduce ;
47 : symbols>flags ( symbols assoc -- flag-bits )
54 GENERIC: (bitfield-quot) ( spec -- quot )
56 M: integer (bitfield-quot) ( spec -- quot )
57 [ swapd shift bitor ] curry ;
59 M: pair (bitfield-quot) ( spec -- quot )
60 first2 over word? [ [ swapd execute ] dip ] [ ] ?
61 [ shift bitor ] append 2curry ;
65 MACRO: bitfield ( bitspec -- )
66 [ 0 ] [ (bitfield-quot) compose ] reduce ;
77 8 <bits> 0 [ [ 1 + ] when ] reduce
78 ] B{ } map-as '[ HEX: ff bitand _ nth-unsafe ]
79 (( byte -- table )) define-declared
81 \ byte-bit-count make-inline
85 GENERIC: (bit-count) ( x -- n )
91 [ -8 shift byte-bit-count ]
92 [ -16 shift byte-bit-count ]
93 [ -24 shift byte-bit-count ]
99 [ byte-bit-count ] [ -8 shift (bit-count) ] bi +
104 : bit-count ( x -- n )
105 dup 0 < [ bitnot ] when (bit-count) ; inline
107 ! Signed byte array to integer conversion
108 : signed-le> ( bytes -- x )
109 [ le> ] [ length 8 * 1 - on-bits ] bi
110 2dup > [ bitnot bitor ] [ drop ] if ;
112 : signed-be> ( bytes -- x )
113 <reversed> signed-le> ;
115 : >signed ( x n -- y )
116 2dup neg 1 + shift 1 = [ 2^ - ] [ drop ] if ;
118 : >odd ( n -- int ) 0 set-bit ; foldable
120 : >even ( n -- int ) 0 clear-bit ; foldable
122 : next-even ( m -- n ) >even 2 + ; foldable
124 : next-odd ( m -- n ) dup even? [ 1 + ] [ 2 + ] if ; foldable