! Copyright (C) 2007, 2010 Slava Pestov.
! See http://factorcode.org/license.txt for BSD license.
-USING: alien alien.data accessors math alien.accessors kernel
-kernel.private sequences sequences.private byte-arrays
-parser prettyprint.custom fry ;
+USING: alien alien.data accessors io.binary math math.bitwise
+alien.accessors kernel kernel.private sequences
+sequences.private byte-arrays parser prettyprint.custom fry
+locals ;
IN: bit-arrays
TUPLE: bit-array
: n>byte ( m -- n ) -3 shift ; inline
-: byte/bit ( n alien -- byte bit )
- over n>byte alien-unsigned-1 swap 7 bitand ; inline
+: bit/byte ( n -- bit byte ) [ 7 bitand ] [ n>byte ] bi ; inline
-: set-bit ( ? byte bit -- byte )
- 2^ rot [ bitor ] [ bitnot bitand ] if ; inline
+: bit-index ( n bit-array -- bit# byte# byte-array )
+ [ >fixnum bit/byte ] [ underlying>> ] bi* ; inline
: bits>cells ( m -- n ) 31 + -5 shift ; inline
: (set-bits) ( bit-array n -- )
[ [ length bits>cells ] keep ] dip swap underlying>>
- '[ 2 shift [ _ _ ] dip set-alien-unsigned-4 ] each-integer ; inline
+ '[ [ _ _ ] dip 4 * set-alien-unsigned-4 ] each-integer ; inline
: clean-up ( bit-array -- )
! Zero bits after the end.
M: bit-array length length>> ; inline
M: bit-array nth-unsafe
- [ >fixnum ] [ underlying>> ] bi* byte/bit bit? ; inline
+ bit-index nth-unsafe swap bit? ; inline
+
+:: toggle-bit ( ? n x -- y )
+ x n ? [ set-bit ] [ clear-bit ] if ; inline
M: bit-array set-nth-unsafe
- [ >fixnum ] [ underlying>> ] bi*
- [ byte/bit set-bit ] 2keep
- swap n>byte set-alien-unsigned-1 ; inline
+ bit-index [ toggle-bit ] change-nth-unsafe ; inline
GENERIC: clear-bits ( bit-array -- )
bit-array boa
dup clean-up ; inline
-M: bit-array byte-length length 7 + -3 shift ; 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>
- ] [
- [ log2 1 + <bit-array> 0 ] keep
- [ dup 0 = ] [
- [ pick underlying>> pick set-alien-unsigned-1 ] keep
- [ 1 + ] [ -8 shift ] bi*
- ] until 2drop
- ] if ;
+ dup 0 =
+ [ <bit-array> ]
+ [ dup log2 1 + [ nip ] [ bits>bytes >le ] 2bi bit-array boa ] if ;
: bit-array>integer ( bit-array -- n )
- 0 swap underlying>> dup length iota <reversed> [
- alien-unsigned-1 swap 8 shift bitor
- ] with each ;
+ underlying>> le> ;
INSTANCE: bit-array sequence