37 lines
1.1 KiB
Factor
37 lines
1.1 KiB
Factor
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! Copyright (C) 2009 Daniel Ehrenberg.
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! See http://factorcode.org/license.txt for BSD license.
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USING: regexp.nfa regexp.dfa regexp.minimize kernel sequences
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assocs regexp.classes hashtables accessors ;
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IN: regexp.negation
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: ast>dfa ( parse-tree -- minimal-dfa )
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construct-nfa construct-dfa minimize ;
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CONSTANT: fail-state -1
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: add-default-transition ( state's-transitions -- new-state's-transitions )
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clone dup
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[ [ fail-state ] dip keys <or-class> <not-class> ] keep set-at ;
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: fail-state-recurses ( transitions -- new-transitions )
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clone dup
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[ fail-state any-char associate fail-state ] dip set-at ;
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: add-fail-state ( transitions -- new-transitions )
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[ add-default-transition ] assoc-map
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fail-state-recurses ;
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: assoc>set ( assoc -- keys-set )
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[ drop dup ] assoc-map ;
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: inverse-final-states ( transition-table -- final-states )
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[ transitions>> assoc>set ] [ final-states>> ] bi assoc-diff ;
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: negate-table ( transition-table -- transition-table )
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clone
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[ add-fail-state ] change-transitions
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dup inverse-final-states >>final-states ;
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! M: negation nfa-node ( node -- )
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! ast>dfa negate-table adjoin-dfa ;
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