32 lines
841 B
Factor
32 lines
841 B
Factor
! Copyright (C) 2008 Slava Pestov, Doug Coleman.
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! See http://factorcode.org/license.txt for BSD license.
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USING: assocs hashtables kernel sequences vectors ;
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IN: sets
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: (prune) ( elt hash vec -- )
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3dup drop key?
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[ [ drop dupd set-at ] [ nip push ] [ ] 3tri ] unless
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3drop ; inline
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: prune ( seq -- newseq )
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[ ] [ length <hashtable> ] [ length <vector> ] tri
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[ [ (prune) ] 2curry each ] keep ;
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: unique ( seq -- assoc )
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[ dup ] H{ } map>assoc ;
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: (all-unique?) ( elt hash -- ? )
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2dup key? [ 2drop f ] [ dupd set-at t ] if ;
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: all-unique? ( seq -- ? )
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dup length <hashtable> [ (all-unique?) ] curry all? ;
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: intersect ( seq1 seq2 -- newseq )
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unique [ key? ] curry subset ;
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: diff ( seq1 seq2 -- newseq )
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swap unique [ key? not ] curry subset ;
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: union ( seq1 seq2 -- newseq )
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append prune ;
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