24 lines
734 B
Factor
24 lines
734 B
Factor
! Copyright (C) 2005 Slava Pestov.
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! See http://factor.sf.net/license.txt for BSD license.
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IN: generic
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USING: errors hashtables kernel lists math parser strings
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sequences vectors words ;
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! Complement metaclass, contains all objects not in a certain class.
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SYMBOL: complement
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: complement-predicate ( complement -- list )
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"predicate" word-prop [ not ] append ;
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: complement-types ( class -- types )
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"complement" word-prop types object types seq-diff ;
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: define-complement ( class complement -- )
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2dup "complement" set-word-prop
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dupd complement-predicate "predicate" set-word-prop
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dup dup complement-types "types" set-word-prop
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complement define-class ;
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PREDICATE: word complement metaclass complement = ;
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