use reject instead of [ ... not ] filter.

[factor.git] / basis / regexp / disambiguate / disambiguate.factor

diff --git a/basis/regexp/disambiguate/disambiguate.factor b/basis/regexp/disambiguate/disambiguate.factor
index 1243ab7cc1672851dd43df2520162563bbd68a6a..256770c4e522fd05073b78d1a77f42c29134f7d9 100644 (file)
--- a/basis/regexp/disambiguate/disambiguate.factor
+++ b/basis/regexp/disambiguate/disambiguate.factor
@@ -1,7 +1,8 @@
 ! 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 ;
+arrays sets regexp.dfa math fry regexp.minimize regexp.ast
+locals regexp.transition-tables ;
 IN: regexp.disambiguate
 
 TUPLE: parts in out ;
@@ -9,30 +10,63 @@ TUPLE: parts in out ;
 : make-partition ( choices classes -- partition )
     zip [ first ] partition [ values ] bi@ parts boa ;
 
-: powerset-partition ( classes -- partitions )
-    [ length [ 2^ ] keep ] keep '[
-        _ <bits> _ make-partition
-    ] map ;
+: powerset-partition ( sequence -- partitions )
+    [ length [ 2^ iota ] keep ] keep '[ _ <bits> _ make-partition ] map rest ;
 
 : partition>class ( parts -- class )
-    [ in>> ] [ out>> ] bi
-    [ <or-class> ] bi@ <not-class> 2array <and-class> ;
+    [ out>> [ <not-class> ] map ]
+    [ in>> <and-class> ] bi
+    prefix <and-class> ;
+
+: 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 )
+    classes [ integer? ] partition :> ( integers classes )
+    
+    classes powerset-partition classes integers add-integers
+    [ [ partition>class ] keep 2array ] map [ first ] filter
+    integers [ classes singleton-partition ] map append ;
+
+: new-transitions ( transitions -- assoc ) ! assoc is class, partition
+    values [ keys ] gather
+    [ tagged-epsilon? ] reject
+    class-partitions ;
 
 : get-transitions ( partition state-transitions -- next-states )
-    [ in>> ] dip '[ _ at ] map prune ;
-
-: disambiguate ( dfa -- nfa )  
-    [
-        [
-            [ keys powerset-partition ] keep '[
-                [ partition>class ]
-                [ _ get-transitions ] bi
-            ] H{ } map>assoc
-            [ drop ] assoc-filter 
+    [ 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 '[
+            [
+                _ swap '[ _ get-transitions ] assoc-map
+                [ nip empty? not ] assoc-filter 
+            ] preserving-epsilon
         ] assoc-map
     ] change-transitions ;
-
-: nfa>dfa ( nfa -- dfa )
-    construct-dfa
-    minimize disambiguate
-    construct-dfa minimize ;