X-Git-Url: http://git.megacz.com/?p=sbp.git;a=blobdiff_plain;f=src%2Fedu%2Fberkeley%2Fsbp%2FSequence.java;h=d274013904da23504c899ae9ab62651a2f7e1c63;hp=83d9b6f16bd3dda24d8b662c430eb71dc1ea1775;hb=21da21b94e794fa4d7c7207327764895d92ea528;hpb=f33c05adc5aa3dd324c5352cdbd6f4b55359acad

diff --git a/src/edu/berkeley/sbp/Sequence.java b/src/edu/berkeley/sbp/Sequence.java
index 83d9b6f..d274013 100644
--- a/src/edu/berkeley/sbp/Sequence.java
+++ b/src/edu/berkeley/sbp/Sequence.java
@@ -36,6 +36,8 @@ public abstract class Sequence extends Element implements Iterable<Element> {
     ////////////////////////////////////////////////////////////////////////////////
 
     public Element noFollow = null;
+    public String name = null;
+    public void setName(String name) { this.name = name; }
     public final Topology noFollow() { return noFollow==null ? null : noFollow.toAtom(); }
 
     Topology toAtom() {
@@ -45,9 +47,11 @@ public abstract class Sequence extends Element implements Iterable<Element> {
 
     protected final Element[] elements;
 
+          HashSet<Sequence> needed;
+          HashSet<Sequence> hated;
     final HashSet<Sequence> needs;
     final HashSet<Sequence> hates;
-          boolean           lame  = false;
+    public boolean           lame  = false;
 
     final Position          firstp;
     Position firstp() { return firstp; }
@@ -56,6 +60,12 @@ public abstract class Sequence extends Element implements Iterable<Element> {
     protected Sequence(Element[] elements, HashSet<Sequence> and, HashSet<Sequence> not) {
         this.needs = and==null ? new HashSet<Sequence>() : and;
         this.hates = not==null ? new HashSet<Sequence>() : not;
+        if (this.needs != null)
+            for(Sequence s : this.needs)
+                (s.needed==null?(s.needed=new HashSet<Sequence>()):s.needed).add(this);
+        if (this.hates != null)
+            for(Sequence s : this.hates)
+                (s.hated==null?(s.hated=new HashSet<Sequence>()):s.hated).add(this);
         this.elements = elements;
         this.firstp = new Position(0);
     }
@@ -66,8 +76,7 @@ public abstract class Sequence extends Element implements Iterable<Element> {
     Forest epsilonForm() {
         if (epsilonForm==null) {
             epsilonForm = new Forest.Ref();
-            Forest fo = firstp().rewrite(null);
-            epsilonForm.merge(fo);
+            epsilonForm.merge(firstp().rewrite2(null));
         }
         return epsilonForm;
     }
@@ -91,11 +100,6 @@ public abstract class Sequence extends Element implements Iterable<Element> {
         }
 
         boolean isFirst() { return pos==0; }
-        boolean isRightNullable(Walk.Cache cache) {
-            if (isLast()) return true;
-            if (!element().possiblyEpsilon(cache)) return false;
-            return next().isRightNullable(cache);
-        }
 
         /** the element immediately after this Position, or null if this is the last Position */
         public Element  element() { return pos>=elements.length ? null : elements[pos]; }
@@ -112,8 +116,11 @@ public abstract class Sequence extends Element implements Iterable<Element> {
         // Reduction /////////////////////////////////////////////////////////////////////////////////
 
         final <T> Forest<T> rewrite(Token.Location loc) {
-            if (this==firstp() && eps) return epsilonForm;
-            eps = true;
+            if (this==firstp()) return epsilonForm();
+            return rewrite2(loc);
+        }
+
+        final <T> Forest<T> rewrite2(Token.Location loc) {
             for(int i=0; i<pos; i++) if (holder[i]==null) throw new Error("realbad " + i);
             for(int i=pos; i<elements.length; i++) {
                 if (holder[i]==null) holder[i] = elements[i].epsilonForm();
@@ -121,7 +128,6 @@ public abstract class Sequence extends Element implements Iterable<Element> {
             }
             Forest<T> ret = Sequence.this.postReduce(loc, holder);
             for(int k=0; k<pos; k++) holder[k] = null; // to help GC
-            if (this==firstp()) { if (epsilonForm==null) epsilonForm=new Forest.Ref(); epsilonForm.merge(ret); return epsilonForm; }
             return ret;
         }
 
@@ -131,7 +137,7 @@ public abstract class Sequence extends Element implements Iterable<Element> {
             for(Position p = Sequence.this.firstp(); p != null; p = p.next()) {
                 ret.append(' ');
                 if (p==this) ret.append(" | ");
-                if (p.element()!=null) ret.append(p.element().possiblyEpsilon(null) ? "["+p.element()+"]" : p.element());
+                if (p.element()!=null) ret.append(p.element());
                 else                   ret.append(' ');
             }
             ret.append("}>");
@@ -159,7 +165,7 @@ public abstract class Sequence extends Element implements Iterable<Element> {
         private final Object result;
         public Constant(Element[] e, Object result, HashSet<Sequence> and, HashSet<Sequence> not) { super(e, and, not); this.result = result; }
         public <T> Forest<T> postReduce(Token.Location loc, Forest<T>[] args) {
-            return (Forest<T>)Forest.leaf(loc, result, this);
+            return (Forest<T>)Forest.leaf(loc, result);
         }
         static class Drop extends Constant {
             public Drop(Element[] e, HashSet<Sequence> and, HashSet<Sequence> not, boolean lame) {
@@ -174,27 +180,27 @@ public abstract class Sequence extends Element implements Iterable<Element> {
         private final int idx;
         public Singleton(Element e, HashSet<Sequence> and, HashSet<Sequence> not) { this(new Element[] { e }, 0, and, not); }
         public Singleton(Element[] e, int idx, HashSet<Sequence> and, HashSet<Sequence> not) { super(e, and, not); this.idx = idx; }
-        public <T> Forest<T> postReduce(Token.Location loc, Forest<T>[] args) { return (Forest<T>)Forest.singleton(loc, args[idx], this); }
+        public <T> Forest<T> postReduce(Token.Location loc, Forest<T>[] args) { return (Forest<T>)Forest.singleton(loc, args[idx]); }
     }
 
-    static class Unwrap extends Sequence {
+    public static class Unwrap extends Sequence {
         private boolean[] drops;
         public Unwrap(Element[] e, HashSet<Sequence> and, HashSet<Sequence> not)                  { super(e, and, not); this.drops = null; }
         public Unwrap(Element[] e, boolean[] drops, HashSet<Sequence> and, HashSet<Sequence> not) { super(e, and, not); this.drops = drops; }
         public <T> Forest<T> postReduce(Token.Location loc, Forest<T>[] args) {
             for(int i=0; i<args.length; i++) if (args[i]==null) throw new Error();
-            if (drops==null) return Forest.create(loc, null, args, this, true, false);
+            if (drops==null) return Forest.create(loc, null, args, true, false);
             int count = 0;
             for(int i=0; i<drops.length; i++) if (!drops[i]) count++;
             Forest<T>[] args2 = new Forest[count];
             int j = 0;
             for(int i=0; i<args.length; i++) if (!drops[i]) args2[j++] = args[i];
-            return Forest.create(loc, null, args2, this, true, false);            
+            return Forest.create(loc, null, args2, true, false);            
         }
     }
 
     static class RewritingSequence extends Sequence {
-        private final Object tag;
+        /*private*/public final Object tag;
         private final boolean[] drops;
         private int count = 0;
         public RewritingSequence(Object tag, Element[] e, HashSet<Sequence> and, HashSet<Sequence> not) { this(tag, e, null, and, not); }
@@ -209,7 +215,7 @@ public abstract class Sequence extends Element implements Iterable<Element> {
             int j = 0;
             for(int i=0; i<args.length; i++) if (!drops[i]) args2[j++] = args[i];
             //System.out.println("reduce \""+tag+"\"");
-            return Forest.create(loc, (T)tag, args2, this, false, false);
+            return Forest.create(loc, (T)tag, args2, false, false);
         }
         public StringBuffer toString(StringBuffer sb, boolean spacing) {
             int len = sb.length();