added tracking of position to Forest nodes

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

diff --git a/src/edu/berkeley/sbp/Forest.java b/src/edu/berkeley/sbp/Forest.java
index a8c44f0..e74d81e 100644 (file)
--- a/src/edu/berkeley/sbp/Forest.java
+++ b/src/edu/berkeley/sbp/Forest.java
@@ -1,6 +1,6 @@
 package edu.berkeley.sbp;
 import edu.berkeley.sbp.*;
-import edu.berkeley.sbp.*;
+import edu.berkeley.sbp.Sequence.Position;
 import edu.berkeley.sbp.util.*;
 import java.io.*;
 import java.util.*;
@@ -11,19 +11,27 @@ public abstract class Forest<T> /*extends PrintableTree<Forest.MyBody<T>>*/ impl
 
     /** assume that this forest contains exactly one tree and return it; otherwise throw an exception */
     public final Tree<T> expand1() throws Ambiguous, ParseFailed {
-        Iterator<Tree<T>> it = expand(true).iterator();
-        if (!it.hasNext()) throw new ParseFailed();
-        return it.next();
+        try {
+            Iterator<Tree<T>> it = expand(true).iterator();
+            if (!it.hasNext()) throw new ParseFailed();
+            return it.next();
+        } catch (InnerAmbiguous ia) { throw new Ambiguous(ia.f); }
     }
 
     /** expand this forest into a set of trees */
     public HashSet<Tree<T>> expand(boolean toss) {
+        //if (toss) scan();
         final HashSetTreeConsumer<T> ret = new HashSetTreeConsumer<T>();
         visit(new TreeMaker2<T>(toss, ret), null, null);
-        if (toss && ret.size() > 1) throw new Ambiguous(this);
+        if (toss && ret.size() > 1) throw new InnerAmbiguous(this);
         return ret;
     }
 
+    private static class InnerAmbiguous extends RuntimeException {
+        public final Forest<?> f;
+        public InnerAmbiguous(Forest<?> f) { this.f = f; }
+    }
+
     public static interface TreeConsumer<T> {
         public void addTree(Tree<T> t);
     }
@@ -31,11 +39,14 @@ public abstract class Forest<T> /*extends PrintableTree<Forest.MyBody<T>>*/ impl
         public void addTree(Tree<T> t) { super.add(t); }
     }
 
-    static        <T> Forest<T> singleton(Input.Location loc)                       { return create(loc, null, new Forest[] { }, false, true); }
-    static        <T> Forest<T> singleton(Input.Location loc, Forest<T> body)       { return create(loc, null, new Forest[] { body },  false, true); }
-    static        <T> Forest<T> leaf(Input.Location loc, T tag) { return create(loc, tag, null, false, false); }
-    public static <T> Forest<T> create(Input.Location loc, T tag, Forest<T>[] tokens, boolean unwrap, boolean singleton) {
-        return new MyBody<T>(loc, tag, tokens, unwrap, singleton);
+    static        <T> Forest<T> singleton(Input.Location loc, Position p) {
+        return create(loc, null, new Forest[] { }, false, true, p); }
+    static        <T> Forest<T> singleton(Input.Location loc, Forest<T> body, Position p) {
+        return create(loc, null, new Forest[] { body },  false, true, p); }
+    static        <T> Forest<T> leaf(Input.Location loc, T tag, Position p) { return create(loc, tag, null, false, false, p); }
+
+    public static <T> Forest<T> create(Input.Location loc, T tag, Forest<T>[] tokens, boolean unwrap, boolean singleton, Position p) {
+        return new MyBody<T>(loc, tag, tokens, unwrap, singleton, p);
     }
 
     // Body //////////////////////////////////////////////////////////////////////////////
@@ -55,8 +66,9 @@ public abstract class Forest<T> /*extends PrintableTree<Forest.MyBody<T>>*/ impl
         private final Forest<T>[]       tokens;
         private final boolean           unwrap;
         private final boolean           singleton;
+        private final Sequence.Position reduction;
 
-        private MyBody(Input.Location loc, T tag, Forest<T>[] tokens, boolean unwrap, boolean singleton) {
+        private MyBody(Input.Location loc, T tag, Forest<T>[] tokens, boolean unwrap, boolean singleton, Position reduction) {
             this.location = loc;
             this.tag = tag;
             this.tokens = tokens==null ? emptyForestArray : new Forest[tokens.length];
@@ -64,6 +76,7 @@ public abstract class Forest<T> /*extends PrintableTree<Forest.MyBody<T>>*/ impl
             if (tokens != null) for(int i=0; i<tokens.length; i++) if (tokens[i]==null) throw new Error(i+"");
             this.unwrap = unwrap;
             this.singleton = singleton;
+            this.reduction = reduction;
         }
 
         public void expand(final int i, final TreeMaker<T> h) {