! Copyright (C) 2009 Daniel Ehrenberg.
! See http://factorcode.org/license.txt for BSD license.
USING: kernel accessors regexp.classes math.bits assocs sequences
-arrays sets regexp.dfa math fry regexp.minimize regexp.ast regexp.transition-tables ;
+arrays sets regexp.dfa math fry regexp.minimize regexp.ast
+locals regexp.transition-tables ;
IN: regexp.disambiguate
TUPLE: parts in out ;
: make-partition ( choices classes -- partition )
zip [ first ] partition [ values ] bi@ parts boa ;
-: powerset-partition ( classes -- partitions )
+: powerset-partition ( sequence -- partitions )
[ length [ 2^ ] keep ] keep '[
_ <bits> _ make-partition
] map rest ;
[ in>> <and-class> ] bi
prefix <and-class> ;
-: get-transitions ( partition state-transitions -- next-states )
- [ in>> ] dip '[ _ at ] gather sift ;
+: singleton-partition ( integer non-integers -- {class,partition} )
+ dupd
+ '[ _ [ class-member? ] with filter ] keep
+ prefix f parts boa
+ 2array ;
+
+: add-out ( seq partition -- partition' )
+ [ out>> append ] [ in>> ] bi swap parts boa ;
+
+: intersection ( seq -- elts )
+ [ f ] [ unclip [ intersect ] reduce ] if-empty ;
+
+: meaningful-integers ( partition table -- integers )
+ [ [ in>> ] [ out>> ] bi ] dip
+ '[ [ _ at ] map intersection ] bi@ diff ;
+
+: class-integers ( classes integers -- table )
+ '[ _ over '[ _ class-member? ] filter ] H{ } map>assoc ;
+
+: add-integers ( partitions classes integers -- partitions )
+ class-integers '[
+ [ _ meaningful-integers ] keep add-out
+ ] map ;
+
+: class-partitions ( classes -- assoc )
+ [ integer? ] partition [
+ dup powerset-partition spin add-integers
+ [ [ partition>class ] keep 2array ] map
+ [ first ] filter
+ ] [ '[ _ singleton-partition ] map ] 2bi append ;
: new-transitions ( transitions -- assoc ) ! assoc is class, partition
values [ keys ] gather
[ tagged-epsilon? not ] filter
- powerset-partition
- [ [ partition>class ] keep ] { } map>assoc
- [ drop ] assoc-filter ;
+ class-partitions ;
+
+: get-transitions ( partition state-transitions -- next-states )
+ [ in>> ] dip '[ _ at ] gather sift ;
: preserving-epsilon ( state-transitions quot -- new-state-transitions )
[ [ drop tagged-epsilon? ] assoc-filter ] bi
assoc-union H{ } assoc-like ; inline
+
: disambiguate ( nfa -- nfa )
expand-ors [
dup new-transitions '[