src/edu/berkeley/sbp/Tree.java

   1 package edu.berkeley.sbp;
   2 import edu.berkeley.sbp.*;
   3 import edu.berkeley.sbp.util.*;
   4 import edu.berkeley.sbp.bind.*;
   5 import java.io.*;
   6 import java.util.*;
   7 import java.lang.reflect.*;
   8
   9 /** a tree (or node in a tree); see jargon.txt for details */
  10 public class Tree<T>
  11     extends PrintableTree<Tree<T>>
  12     implements Iterable<Tree<T>>,
  13                GraphViz.ToGraphViz {
  14
  15     private final Input.Region location;
  16     private final T            head;
  17     private final Tree<T>[]    children;
  18     private final boolean      lift;
  19
  20     public T                 head()        { return head; }
  21
  22     private Tree<T> lifted() { return children[children.length-1]; }
  23
  24     public int               numChildren() {
  25         return lift
  26             ? (children.length-1)+lifted().numChildren()
  27             : children.length;
  28     }
  29     public Iterable<Tree<T>> children()    { return this; }
  30     public Iterator<Tree<T>> iterator()    {
  31         return lift
  32             ? new ConcatenateIterator(new ArrayIterator(children, 0, children.length-1),
  33                                       children[children.length-1].iterator())
  34             : new ArrayIterator(children);
  35     }
  36
  37     public Tree<T> child(int i)  {
  38         return lift && i >= children.length-1
  39             ? children[children.length-1].child(i-(children.length-1))
  40             : children[i];
  41     }
  42
  43     public Input.Region    getRegion() { return location; }
  44
  45     public Tree(Input.Region loc, T head)                     { this(loc, head, null); }
  46     public Tree(Input.Region loc, T head, Tree<T>[] children) { this(loc, head, children, false); }
  47     public Tree(Input.Region loc, T head, Tree<T>[] children, boolean lift) {
  48         this.location = loc;
  49         this.head = head;
  50         this.lift = lift && children != null && children.length > 0;
  51
  52         Tree<T>[] children2 = children==null ? new Tree[0] : new Tree[children.length];
  53         if (children != null) System.arraycopy(children, 0, children2, 0, children.length);
  54         this.children = children2;
  55     }
  56
  57
  58     // PrintableTree /////////////////////////////////////////////////////////////////////////////
  59
  60     protected String headToString() { return head()==null?null:head().toString(); }
  61     protected String headToJava()   {
  62       // FIXME
  63         if (head()==null) return null;
  64         if (head() instanceof ToJava) {
  65             StringBuffer sb = new StringBuffer();
  66             ((ToJava)head()).toJava(sb);
  67             return sb.toString();
  68         }
  69         return (head()==null?"null":("\""+StringUtil.toJavaString(head().toString())+"\""));
  70     }
  71     protected String left()   { return "{"; }
  72     protected String right()  { return "}"; }
  73     protected boolean ignoreSingleton() { return false; }
  74
  75
  76     // ToGraphViz /////////////////////////////////////////////////////////////////////////////
  77
  78     public GraphViz.Node toGraphViz(GraphViz gv) {
  79         if (gv.hasNode(this)) return gv.createNode(this);
  80         GraphViz.Node n = gv.createNode(this);
  81         n.label = head()==null ? "" : head().toString();
  82         //n.color = "red";
  83         for(Tree t : this) n.edge(t, null);
  84         return n;
  85     }
  86     public boolean isTransparent() { return false; }
  87     public boolean isHidden() { return false; }
  88
  89     public static interface TreeFunctor<T,R> extends Functor<Iterable<Tree<T>>, R> { }
  90
  91
  92     public static class RawBindingFunctor<T> implements TreeFunctor<T,Object>, ToJava {
  93         private Binding _binding;
  94         private String _toString;
  95         public RawBindingFunctor(String toString, Binding binding) {
  96             this._binding = binding;
  97             this._toString = toString;
  98         }
  99         public String toString() {
 100             return _toString;
 101         }
 102         public void toJava(StringBuffer sb) {
 103             sb.append("new Tree.RawBindingFunctor(");
 104             sb.append("\"");
 105             sb.append(StringUtil.toJavaString(_toString));
 106             sb.append("\", ");
 107             _binding.toJava(sb);
 108             sb.append(")");
 109         }
 110         public Object invoke(Iterable<Tree<T>> t) {
 111             return _binding.invoke(new Object[] { t });
 112         }
 113     }
 114
 115     public static class BindingFunctor<T> implements TreeFunctor<T,Object>, ToJava {
 116         private Binding _binding;
 117         private String _toString;
 118         public String toString() {
 119             return _toString;
 120         }
 121         public BindingFunctor(String toString, Binding binding) {
 122             this._binding = binding;
 123             this._toString = toString;
 124         }
 125         public void toJava(StringBuffer sb) {
 126             sb.append("new Tree.BindingFunctor(");
 127             sb.append("\"");
 128             sb.append(StringUtil.toJavaString(_toString));
 129             sb.append("\", ");
 130             _binding.toJava(sb);
 131             sb.append(")");
 132         }
 133         public Object invoke(Iterable<Tree<T>> t) {
 134             ArrayList ret = new ArrayList();
 135             for(Tree tc : t) {
 136                 if (tc.head() != null && tc.head() instanceof Functor)
 137                     ret.add(((Tree.TreeFunctor<Object,Object>)tc.head()).invoke(tc.children()));
 138                 else if (tc.numChildren() == 0)
 139                     ret.add(tc.head());
 140                 else {
 141                     System.err.println("FIXME: don't know what to do about " + tc);
 142                     ret.add(null);
 143                 }
 144             }
 145             Object[] o = (Object[])ret.toArray(new Object[0]);
 146             return _binding.invoke(o);
 147         }
 148     }
 149
 150 }