1 ! Copyright (C) 2009 Daniel Ehrenberg.
2 ! See http://factorcode.org/license.txt for BSD license.
3 USING: kernel accessors regexp.classes math.bits assocs sequences
4 arrays sets regexp.dfa math fry regexp.minimize regexp.ast ;
5 IN: regexp.disambiguate
9 : make-partition ( choices classes -- partition )
10 zip [ first ] partition [ values ] bi@ parts boa ;
12 : powerset-partition ( classes -- partitions )
13 [ length [ 2^ ] keep ] keep '[
14 _ <bits> _ make-partition
17 : partition>class ( parts -- class )
18 [ out>> [ <not-class> ] map ]
19 [ in>> <and-class> ] bi
22 : get-transitions ( partition state-transitions -- next-states )
23 [ in>> ] dip '[ _ at ] gather sift ;
25 : new-transitions ( transitions -- assoc ) ! assoc is class, partition
26 values [ keys ] gather
27 [ tagged-epsilon? not ] filter
29 [ [ partition>class ] keep ] { } map>assoc
30 [ drop ] assoc-filter ;
32 : preserving-epsilon ( state-transitions quot -- new-state-transitions )
33 [ [ drop tagged-epsilon? ] assoc-filter ] bi
34 assoc-union H{ } assoc-like ; inline
36 : disambiguate ( nfa -- nfa )
38 dup new-transitions '[
40 _ swap '[ _ get-transitions ] assoc-map
41 [ nip empty? not ] assoc-filter
44 ] change-transitions ;