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 T            head;
  16     private final Tree<T>[]    children;
  17     private final Input.Region location;
  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         if (lift && children.length > 0)
  26             return (children.length-1)+lifted().numChildren();
  27         return children.length;
  28     }
  29     public Iterable<Tree<T>> children()    { return this; }
  30     public Iterator<Tree<T>> iterator()    {
  31         if (lift)
  32             return new ConcatenateIterator(new ArrayIterator(children, 0, children.length-1),
  33                                            children[children.length-1].iterator());
  34         return new ArrayIterator(children);
  35     }
  36     public Tree<T>           child(int i)  {
  37         if (lift && i >= children.length-1)
  38             return children[children.length-1].child(i-(children.length-1));
  39         return children[i];
  40     }
  41
  42     public Input.Region    getRegion() { return location; }
  43
  44     public Tree(Input.Region loc, T head)                   { this(loc, head, null); }
  45     public Tree(Input.Region loc, T head, Tree<T>[] children) { this(loc, head, children, false); }
  46     public Tree(Input.Region loc, T head, Tree<T>[] children, boolean lift) {
  47         this.location = loc;
  48         this.head = head;
  49         this.lift = lift;
  50
  51         Tree<T>[] children2 = children==null ? new Tree[0] : new Tree[children.length];
  52         if (children != null) System.arraycopy(children, 0, children2, 0, children.length);
  53         this.children = children2;
  54     }
  55
  56     protected String headToString() { return head()==null?null:head().toString(); }
  57     protected String headToJava()   {
  58       // FIXME
  59         if (head()==null) return null;
  60         if (head() instanceof ToJava) {
  61             StringBuffer sb = new StringBuffer();
  62             ((ToJava)head()).toJava(sb);
  63             return sb.toString();
  64         }
  65         return (head()==null?"null":("\""+StringUtil.toJavaString(head().toString())+"\""));
  66     }
  67     protected String left()   { return "{"; }
  68     protected String right()  { return "}"; }
  69     protected boolean ignoreSingleton() { return false; }
  70
  71     public GraphViz.Node toGraphViz(GraphViz gv) {
  72         if (gv.hasNode(this)) return gv.createNode(this);
  73         GraphViz.Node n = gv.createNode(this);
  74         n.label = head()==null ? "" : head().toString();
  75         //n.color = "red";
  76         for(Tree t : this) n.edge(t, null);
  77         return n;
  78     }
  79     public boolean isTransparent() { return false; }
  80     public boolean isHidden() { return false; }
  81
  82     public static interface TreeFunctor<T,R> extends Functor<Iterable<Tree<T>>, R> {
  83     }
  84
  85     public static class ArrayBuildingTreeFunctor<T> implements TreeFunctor<T,T[]>, ToJava {
  86
  87         public void toJava(StringBuffer sb) { sb.append("new Tree.ArrayBuildingTreeFunctor()"); }
  88         public String toString() { return ""; }
  89
  90         public T[] invoke(Iterable<Tree<T>> t) {
  91             ArrayList ret = new ArrayList();
  92             for(Tree tc : t) {
  93                 if (tc.head() != null && tc.head() instanceof Functor)
  94                     ret.add(((Functor<Iterable<Tree>,Object>)tc.head()).invoke(tc.children()));
  95                 else if (tc.numChildren() == 0)
  96                     ret.add(tc.head());
  97                 else {
  98                     System.err.println("FIXME: don't know what to do about " + tc);
  99                     ret.add(null);
 100                 }
 101             }
 102             return (T[])ret.toArray(new Object[0]);
 103         }
 104     }
 105
 106     public static class RawBindingFunctor<T> implements TreeFunctor<T,Object>, ToJava {
 107         private Binding _binding;
 108         private String _toString;
 109         public RawBindingFunctor(String toString, Binding binding) {
 110             this._binding = binding;
 111             this._toString = toString;
 112         }
 113         public String toString() {
 114             return _toString;
 115         }
 116         public void toJava(StringBuffer sb) {
 117             sb.append("new Tree.RawBindingFunctor(");
 118             sb.append("\"");
 119             sb.append(StringUtil.toJavaString(_toString));
 120             sb.append("\", ");
 121             _binding.toJava(sb);
 122             sb.append(")");
 123         }
 124         public Object invoke(Iterable<Tree<T>> t) {
 125             return _binding.invoke(new Object[] { t });
 126         }
 127     }
 128
 129     public static class BindingFunctor<T> implements TreeFunctor<T,Object>, ToJava {
 130         private Binding _binding;
 131         private String _toString;
 132         public String toString() {
 133             return _toString;
 134         }
 135         public BindingFunctor(String toString, Binding binding) {
 136             this._binding = binding;
 137             this._toString = toString;
 138         }
 139         public void toJava(StringBuffer sb) {
 140             sb.append("new Tree.BindingFunctor(");
 141             sb.append("\"");
 142             sb.append(StringUtil.toJavaString(_toString));
 143             sb.append("\", ");
 144             _binding.toJava(sb);
 145             sb.append(")");
 146         }
 147         public Object invoke(Iterable<Tree<T>> t) {
 148             ArrayList ret = new ArrayList();
 149             for(Tree tc : t) {
 150                 if (tc.head() != null && tc.head() instanceof Functor)
 151                     ret.add(((Tree.TreeFunctor<Object,Object>)tc.head()).invoke(tc.children()));
 152                 else if (tc.numChildren() == 0)
 153                     ret.add(tc.head());
 154                 else {
 155                     System.err.println("FIXME: don't know what to do about " + tc);
 156                     ret.add(null);
 157                 }
 158             }
 159             Object[] o = (Object[])ret.toArray(new Object[0]);
 160             return _binding.invoke(o);
 161         }
 162     }
 163
 164 }