factor/basis/bit-sets/bit-sets.factor

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2.1 KiB
Factor

! Copyright (C) 2009 Slava Pestov.
! See http://factorcode.org/license.txt for BSD license.
USING: accessors bit-arrays fry kernel math math.bitwise
sequences sequences.private sets ;
IN: bit-sets
TUPLE: bit-set { table bit-array read-only } ;
: <bit-set> ( capacity -- bit-set )
<bit-array> bit-set boa ; inline
INSTANCE: bit-set set
M: bit-set in?
over integer? [ table>> ?nth ] [ 2drop f ] if ; inline
M: bit-set adjoin
! This is allowed to throw an error when the elt couldn't
! go in the set
[ t ] 2dip table>> set-nth ;
M: bit-set delete
! This isn't allowed to throw an error if the elt wasn't
! in the set
over integer? [ [ f ] 2dip table>> ?set-nth ] [ 2drop ] if ;
! If you do binary set operations with a bit-set, it's expected
! that the other thing can also be represented as a bit-set
! of the same length.
<PRIVATE
ERROR: check-bit-set-failed ;
: check-bit-set ( bit-set -- bit-set )
dup bit-set? [ check-bit-set-failed ] unless ; inline
: bit-set-map ( seq1 seq2 quot -- seq )
[ drop [ length ] bi@ [ assert= ] keep ]
[ [ [ underlying>> ] bi@ ] dip 2map ] 3bi
bit-array boa ; inline
: (bit-set-op) ( set1 set2 -- table1 table2 )
[ set-like ] keep [ table>> ] bi@ ; inline
: bit-set-op ( set1 set2 quot: ( a b -- c ) -- bit-set )
[ (bit-set-op) ] dip bit-set-map bit-set boa ; inline
PRIVATE>
M: bit-set union
[ bitor ] bit-set-op ;
M: bit-set intersect
[ bitand ] bit-set-op ;
M: bit-set diff
[ bitnot bitand ] bit-set-op ;
M: bit-set subset?
[ intersect ] keep = ;
M: bit-set members
table>> [ length <iota> ] keep '[ _ nth-unsafe ] filter ;
<PRIVATE
: bit-set-like ( set bit-set -- bit-set' )
! Throws an error if there are keys that can't be put
! in the bit set
over bit-set? [ 2dup [ table>> length ] same? ] [ f ] if
[ drop ] [
[ members ] dip table>> length <bit-set>
[ adjoin-all ] keep
] if ;
PRIVATE>
M: bit-set set-like
bit-set-like check-bit-set ; inline
M: bit-set clone
table>> clone bit-set boa ;
M: bit-set cardinality
table>> bit-count ;