refactored Element.reachable()

[sbp.git] / src / edu / berkeley / sbp / Parser.java

diff --git a/src/edu/berkeley/sbp/Parser.java b/src/edu/berkeley/sbp/Parser.java
index 6986a4b..e707eac 100644 (file)
--- a/src/edu/berkeley/sbp/Parser.java
+++ b/src/edu/berkeley/sbp/Parser.java
@@ -13,6 +13,17 @@ public class Parser<T extends Token, R> {
 
     private final Table pt;
 
 
     private final Table pt;
 

+    private static void reachable(Element e, HashSet<Position> h) {
+        if (e instanceof Atom) return;
+        for(Sequence s : ((Union)e))
+            reachable(s.firstp(), h);
+    }
+    private static void reachable(Position p, HashSet<Position> h) {
+        if (h.contains(p)) return;
+        h.add(p);
+        if (p.element() != null) reachable(p.element(), h);
+    }
+

     //public Parser(          Topology top) { this(new Table(   top)); }
     //public Parser(String s, Topology top) { this(new Table(s, top)); }
 
     //public Parser(          Topology top) { this(new Table(   top)); }
     //public Parser(String s, Topology top) { this(new Table(s, top)); }
 

@@ -80,7 +91,7 @@ public class Parser<T extends Token, R> {
         
         public HashSet<Position> closure()       {
             HashSet<Position> hp = new HashSet<Position>();
         
         public HashSet<Position> closure()       {
             HashSet<Position> hp = new HashSet<Position>();

-            start0.reachable(hp);
+            reachable(start0, hp);

             return hp;
         }
         public Position firstPosition()          { return start0seq.firstp(); }
             return hp;
         }
         public Position firstPosition()          { return start0seq.firstp(); }

@@ -223,7 +234,7 @@ public class Parser<T extends Token, R> {
                     if (position.isLast() || !(position.element() instanceof Atom)) continue;
                     Atom a = (Atom)position.element();
                     HashSet<Position> hp = new HashSet<Position>();
                     if (position.isLast() || !(position.element() instanceof Atom)) continue;
                     Atom a = (Atom)position.element();
                     HashSet<Position> hp = new HashSet<Position>();

-                    position.next().reachable(hp);
+                    reachable(position.next(), hp);

                     bag0.addAll(a.dup(), /*clo.walk()*/hp);
                 }
 
                     bag0.addAll(a.dup(), /*clo.walk()*/hp);
                 }
 

@@ -262,7 +273,7 @@ public class Parser<T extends Token, R> {
                     if (ys != null) {
                         for(Element y : ys) {
                             HashSet<Position> hp = new HashSet<Position>();
                     if (ys != null) {
                         for(Element y : ys) {
                             HashSet<Position> hp = new HashSet<Position>();

-                            p.next().reachable(hp);
+                            reachable(p.next(), hp);

                             move.addAll(y, hp);
                         }
                     }
                             move.addAll(y, hp);
                         }
                     }