X-Git-Url: http://git.megacz.com/?p=sbp.git;a=blobdiff_plain;f=src%2Fedu%2Fberkeley%2Fsbp%2FTree.java;h=cce7bfe6a405dadb0b7aa3e2c8f19d803ea73820;hp=8e3020debcaaa95421adaa9561cbcab7169d95dd;hb=e086905f34b249ca1ae83c000859f2c603919a6b;hpb=6a3a36e63c18501aa5a37c6af49f419beaa82759

diff --git a/src/edu/berkeley/sbp/Tree.java b/src/edu/berkeley/sbp/Tree.java
index 8e3020d..cce7bfe 100644
--- a/src/edu/berkeley/sbp/Tree.java
+++ b/src/edu/berkeley/sbp/Tree.java
@@ -1,97 +1,103 @@
+// Copyright 2006-2007 all rights reserved; see LICENSE file for BSD-style license
+
 package edu.berkeley.sbp;
 import edu.berkeley.sbp.*;
 import edu.berkeley.sbp.util.*;
-import edu.berkeley.sbp.bind.*;
 import java.io.*;
 import java.util.*;
 import java.lang.reflect.*;
 
-/** a tree (or node in a tree); see jargon.txt for details */
-public class Tree<T>
-    extends PrintableTree<Tree<T>>
-    implements Iterable<Tree<T>>,
-               GraphViz.ToGraphViz {
+/** <font color=blue>a tree (or node in a tree); see jargon.txt for details</font> */
+public class Tree<NodeType>
+    extends PrintableTree<Tree<NodeType>>
+    implements Iterable<Tree<NodeType>> {
+
+    private static final Tree[] emptyTree = new Tree[0];
+
+    private final Input.Region     location;
+    private final NodeType         ihead;
+    private final Tree<NodeType>[] children;
+
+    /** the number of children the tree has */
+    public int               size() { return children.length; }
 
-    final T           head;
-          Tree<T>[]   children;
-    final Input.Region    location;
+    /** the element at the head of the tree */
+    public NodeType                 head()        { return ihead; }
+    public NodeType              getHead()        { return ihead; }
 
-    public T                 head()        { return head; }
-    public int               numChildren() { return children.length; }
-    public Iterable<Tree<T>> children()    { return new ArrayIterator(children); }
-    public Iterator<Tree<T>> iterator()    { return new ArrayIterator(children); }
-    public Tree<T>           child(int i)  { return children[i]; }
+    /** the tree's children */
+    public Iterable<Tree<NodeType>> children()    { return this; }
 
+    /** the tree's children */
+    public Iterator<Tree<NodeType>> iterator()    { return new ArrayIterator(children); }
+
+    /** get the <tt>i</t>th child */
+    public Tree<NodeType> child(int i)            { return children[i]; }
+
+    /** get the input region that this tree was parsed from */
     public Input.Region    getRegion() { return location; }
 
-    public Tree(Input.Region loc, T head)                   { this(loc, head, null); }
-    public Tree(Input.Region loc, T head, Tree<T>[] children) {
+    public Tree(Input.Region loc, NodeType head) {
+        location = loc;
+        ihead = head;
+        children = emptyTree;
+    }
+    public Tree(Input.Region loc, NodeType head, List<Tree<NodeType>> kids){
+        location = loc;
+        ihead = head;
+        if (kids.size() == 0)
+            children = emptyTree;
+        else {
+            children = new Tree[kids.size()];
+            kids.toArray(children);
+        }
+    }
+    public Tree(Input.Region loc, NodeType head, Tree<NodeType>[] kids) {
+        location = loc;
+        ihead = head;
+        children = (kids == null ? emptyTree : kids.clone());
+    }
+
+    // FIXME: fairly inefficient because we keep copying arrays
+    /** package-private constructor, allows setting the "lift" bit */
+    Tree(Input.Region loc, NodeType head, Tree<NodeType>[] children, boolean[] lifts) {
         this.location = loc;
-        this.head = head;
+        this.ihead = head;
+
+        int count = 0;
+        for(int i=0; i<children.length; i++)
+            count += lifts[i] ? children[i].size() : 1;
 
-        Tree<T>[] children2 = children==null ? new Tree[0] : new Tree[children.length];
-        if (children != null) System.arraycopy(children, 0, children2, 0, children.length);
-        this.children = children2;
+        this.children = new Tree[count];
+        int j = 0;
+        for(int i=0; i<children.length; i++) {
+            if (!lifts[i])
+                this.children[j++] = children[i];
+            else
+                for(int k=0; k<children[i].size(); k++)
+                    this.children[j++] = children[i].child(k);
+        }
     }
 
-    protected String headToString() { return head==null?null:head.toString(); }
+
+    // PrintableTree /////////////////////////////////////////////////////////////////////////////
+
+    protected String headToString() { return head()==null?null:head().toString(); }
     protected String headToJava()   {
       // FIXME
-        if (head==null) return null;
-        if (head instanceof ToJava) {
+        if (head()==null) return null;
+        if (head() instanceof ToJava) {
             StringBuffer sb = new StringBuffer();
-            ((ToJava)head).toJava(sb);
+            try {
+                ((ToJava)head()).toJava(sb);
+            } catch (IOException e) { throw new RuntimeException(e); }
             return sb.toString();
         }
-        return (head==null?"null":("\""+StringUtil.toJavaString(head.toString())+"\""));
+        return (head()==null?"null":("\""+StringUtil.toJavaString(head().toString())+"\""));
     }
     protected String left()   { return "{"; }
     protected String right()  { return "}"; }
     protected boolean ignoreSingleton() { return false; }
 
-    public GraphViz.Node toGraphViz(GraphViz gv) {
-        if (gv.hasNode(this)) return gv.createNode(this);
-        GraphViz.Node n = gv.createNode(this);
-        n.label = head()==null ? "" : head().toString();
-        //n.color = "red";
-        for(Tree t : this) n.edge(t, null);
-        return n;
-    }
-    public boolean isTransparent() { return false; }
-    public boolean isHidden() { return false; }
-
-    public static interface TreeFunctor<T,R> extends Functor<Iterable<Tree<T>>, R> {
-    }
-
-    public static class ArrayBuildingTreeFunctor<T> implements TreeFunctor<T,T[]>, ToJava {
-
-        public void toJava(StringBuffer sb) { sb.append("new Tree.ArrayBuildingTreeFunctor()"); }
-        public String toString() { return ""; }
-        
-        public T[] invoke(Iterable<Tree<T>> t) {
-            ArrayList ret = new ArrayList();
-            for(Tree tc : t) {
-                if (tc.head() != null && tc.head() instanceof Functor)
-                    ret.add(((Functor<Iterable<Tree>,Object>)tc.head()).invoke(tc.children()));
-                else if (tc.numChildren() == 0)
-                    ret.add(tc.head());
-                else {
-                    System.err.println("FIXME: don't know what to do about " + tc);
-                    ret.add(null);
-                }
-            }
-            return (T[])ret.toArray(new Object[0]);
-        }
-    }
-
-    public static class BindingFunctor<T> implements TreeFunctor<T,Object>/*, ToJava*/ {
-        private Binding _binding;
-        public BindingFunctor(Binding binding) {
-            this._binding = binding;
-        }
-        public Object invoke(Iterable<Tree<T>> t) {
-            return _binding.invoke(new Object[] { t });           
-        }
-    }
 
 }