UnwrapLeft, error reporting improvements

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

diff --git a/src/edu/berkeley/sbp/Tree.java b/src/edu/berkeley/sbp/Tree.java
index 102817c..1f55a90 100644 (file)
--- a/src/edu/berkeley/sbp/Tree.java
+++ b/src/edu/berkeley/sbp/Tree.java
@@ -1,42 +1,86 @@
+// Copyright 2006 all rights reserved; see LICENSE file for BSD-style license
+
 package edu.berkeley.sbp;
 import edu.berkeley.sbp.*;
-import edu.berkeley.sbp.*;
 import edu.berkeley.sbp.util.*;
 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>> {
+/** <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 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; }
+
+    /** the element at the head of the tree */
+    public NodeType                 head()        { return ihead; }
+    public NodeType              getHead()        { return ihead; }
+
+    /** the tree's children */
+    public Iterable<Tree<NodeType>> children()    { return this; }
 
-    final T           head;
-          Tree<T>[]   children;
-    final Input.Location    location;
+    /** the tree's children */
+    public Iterator<Tree<NodeType>> iterator()    { return new ArrayIterator(children); }
 
-    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]; }
+    /** get the <tt>i</t>th child */
+    public Tree<NodeType> child(int i)            { return children[i]; }
 
-    public       Input.Location    getLocation() { return location; }
+    /** get the input region that this tree was parsed from */
+    public Input.Region    getRegion() { return location; }
 
-    public Tree(Input.Location loc, T head)                   { this(loc, head, null); }
-    public Tree(Input.Location loc, T head, Tree<T>[] children) {
+    public Tree(Input.Region loc, NodeType head)                            { this(loc, head, null); }
+    public Tree(Input.Region loc, NodeType head, Tree<NodeType>[] children) { this(loc, head, children, false); }
+
+    // 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 lift) {
+        this(loc, head, children, lift, false);
+    }
+    Tree(Input.Region loc, NodeType head, Tree<NodeType>[] children, boolean lift, boolean liftLeft) {
         this.location = loc;
-        this.head = head;
-        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.ihead = head;
+        // FIXME: lift+liftLeft togheter
+        if (liftLeft && children != null && children.length > 0) {
+            Tree<NodeType> last = children[0];
+            this.children = new Tree[(children.length-1)+last.children.length];
+            System.arraycopy(children, 1, this.children, last.children.length, children.length-1);
+            if (last.children.length > 0)
+                System.arraycopy(last.children, 0, this.children, 0, last.children.length);
+        } else if (lift && children != null && children.length > 0) {
+            Tree<NodeType> last = children[children.length-1];
+            this.children = new Tree[(children.length-1)+last.children.length];
+            System.arraycopy(children, 0, this.children, 0, children.length-1);
+            if (last.children.length > 0)
+                System.arraycopy(last.children, 0, this.children, children.length-1, last.children.length);
+        } else {
+            this.children = ArrayUtil.clone(children, Tree.class);
+        }
     }
 
-    /** since Tree instances are immutable, we can cache this to make pretty-printing MUCH faster */
-    public String toString() {
-        if (toString!=null) return toString;
-        return toString = super.toString();
+
+    // PrintableTree /////////////////////////////////////////////////////////////////////////////
+
+    protected String headToString() { return head()==null?null:head().toString(); }
+    protected String headToJava()   {
+      // FIXME
+        if (head()==null) return null;
+        if (head() instanceof ToJava) {
+            StringBuffer sb = new StringBuffer();
+            ((ToJava)head()).toJava(sb);
+            return sb.toString();
+        }
+        return (head()==null?"null":("\""+StringUtil.toJavaString(head().toString())+"\""));
     }
-    private String toString = null;
+    protected String left()   { return "{"; }
+    protected String right()  { return "}"; }
+    protected boolean ignoreSingleton() { return false; }
+
 
-    protected String headToString() { return head==null?null:head.toString(); }
-    protected String headToJava()   { return head==null?null:StringUtil.toJavaString(head+""); }
 }