1 package edu.berkeley.sbp;
2 import edu.berkeley.sbp.*;
3 import edu.berkeley.sbp.Sequence.Position;
4 import edu.berkeley.sbp.util.*;
7 import java.lang.reflect.*;
9 /** an efficient representation of a collection of trees (Tomita's shared packed parse forest) */
10 public abstract class Forest<T> /*extends PrintableTree<Forest.MyBody<T>>*/
11 implements Visitable<Forest.Body<T>>,
15 private static int master_idx = 0;
16 private final int idx = master_idx++;
17 public int toInt() { return idx; }
19 public abstract void expand(TaskList tl, HashSet<Tree<T>> ht);
20 public abstract void gather(TaskList tl, HashSet<Tree<T>>[] ht, HashSet<Tree<T>> target);
22 public static class TaskList extends ArrayList<TaskList.Task> {
23 public interface Task {
24 public void perform();
26 public class ExpandTask implements Task {
29 public ExpandTask(Forest f, HashSet hs) { this.f = f; this.hs = hs; }
30 public void perform() { f.expand(TaskList.this, hs); }
32 public class GatherTask implements Task {
36 public GatherTask(Forest f, HashSet<Tree<?>>[] ht, HashSet<Tree<?>> hs) { this.f = f; this.hs = hs; this.ht = ht;}
37 public void perform() { f.gather(TaskList.this, ht, hs); }
39 public void expand(Forest f, HashSet hs) {
40 add(new ExpandTask(f, hs));
42 public void gather(Forest f, HashSet[] ht, HashSet hs) {
43 add(new GatherTask(f, ht, hs));
47 if (isEmpty()) return;
48 Task task = get(size()-1);
55 /** assume that this forest contains exactly one tree and return it; otherwise throw an exception */
56 public final Tree<T> expand1() throws Ambiguous, ParseFailed {
58 Iterator<Tree<T>> it = expand(true).iterator();
59 if (!it.hasNext()) throw new ParseFailed();
61 } catch (InnerAmbiguous ia) { throw new Ambiguous(ia.f); }
64 /** expand this forest into a set of trees */
65 public HashSet<Tree<T>> expand(boolean toss) {
66 TaskList tl = new TaskList();
67 HashSet<Tree<T>> ret = new HashSet<Tree<T>>();
71 if (toss && ret.size() > 1) throw new InnerAmbiguous(this);
75 private static class InnerAmbiguous extends RuntimeException {
76 public final Forest<?> f;
77 public InnerAmbiguous(Forest<?> f) { this.f = f; }
80 static <T> Forest<T> leaf(Input.Region loc, T tag) { return create(loc, tag, null, false); }
81 public static <T> Forest<T> create(Input.Region loc, T tag, Forest<T>[] tokens, boolean unwrap) {
82 return new MyBody<T>(loc, tag, tokens, unwrap);
84 // Body //////////////////////////////////////////////////////////////////////////////
86 public /*protected*/ static interface Body<T> extends GraphViz.ToGraphViz {
87 void expand(int i, TreeBuilder<T> h);
89 public abstract void edges(GraphViz.Node n);
90 public boolean ambiguous() { return false; }
91 public /*protected*/ static class MyBody<T> extends Forest<T> implements Body<T> /* extends PrintableTree<Forest<T>> implements */ {
93 private final Input.Region location;
95 private final Forest<T>[] tokens;
96 private final boolean unwrap;
98 public boolean isTransparent() { return false; }
99 public boolean isHidden() { return false; }
100 public GraphViz.Node toGraphViz(GraphViz gv) {
101 if (gv.hasNode(this)) return gv.createNode(this);
102 GraphViz.Node n = gv.createNode(this);
103 n.label = headToString()==null?"":headToString();
105 //n.comment = reduction==null?null:reduction+"";
109 boolean edges = false;
110 public void edges(GraphViz.Node n) {
113 for(int i=0; i<tokens.length; i++) {
114 if (i==tokens.length-1 && unwrap && !tokens[i].ambiguous()) {
117 n.edge(tokens[i], null);
122 public <B,C> void visit(Invokable<Forest.Body<T>,B,C> ivbc, B b, C c) {
123 ivbc.invoke(this, b, c);
126 private MyBody(Input.Region loc, T tag, Forest<T>[] tokens, boolean unwrap) {
129 this.tokens = tokens==null ? emptyForestArray : new Forest[tokens.length];
130 if (tokens != null) System.arraycopy(tokens, 0, this.tokens, 0, tokens.length);
131 if (tokens != null) for(int i=0; i<tokens.length; i++) if (tokens[i]==null) throw new Error(i+"");
132 this.unwrap = unwrap;
134 public void gather(TaskList tl, HashSet<Tree<T>>[] ht, HashSet<Tree<T>> target) {
135 gather(tl, ht, target, new Tree[ht.length], 0);
137 private void gather(TaskList tl, HashSet<Tree<T>>[] ht, HashSet<Tree<T>> target, Tree[] trees, int i) {
139 target.add(new Tree<T>(location, tag, trees));
142 for(Tree<T> tree : ht[i]) {
143 if (unwrap && i==trees.length-1) {
144 // I think this is wrong
145 Tree[] trees2 = new Tree[trees.length - 1 + tree.numChildren()];
146 System.arraycopy(trees, 0, trees2, 0, trees.length-1);
147 for(int j=0; j<tree.numChildren(); j++)
148 trees2[trees.length-1+j] = tree.child(j);
149 target.add(new Tree<T>(location, tag, trees2));
152 gather(tl, ht, target, trees, i+1);
157 public void expand(TaskList tl, HashSet<Tree<T>> ht) {
158 HashSet<Tree<T>>[] children = new HashSet[tokens.length];
159 tl.gather(this, children, ht);
160 for(int i=0; i<children.length; i++) {
161 children[i] = new HashSet<Tree<T>>();
162 tl.expand(tokens[i], children[i]);
166 public void expand(final int i, final TreeBuilder<T> h) {
167 if (i==0) h.start(tag, location);
169 if (i==tokens.length) {
170 h.finish(tag, location);
172 } else if (unwrap && i==tokens.length-1) {
173 if (tokens[i] != null)
174 tokens[i].visit(h, null, 0);
177 tokens[i].visit(new TreeBuilder<T>(h.toss) {
178 public void start(T head, Input.Region loc) { }
179 public void addTree(Tree<T> t) { toks.add(t); }
180 public void finish(T head, Input.Region loc) {
181 int old = h.toks.size();
182 h.addTree(new Tree<T>(loc, head, toks.toArray(tree_hint)));
184 while(h.toks.size() > old) h.toks.remove(h.toks.size()-1);
190 protected String headToString() { return tag==null?null:tag.toString(); }
191 protected String headToJava() { return "null"; }
192 protected String left() { return "{"; }
193 protected String right() { return "}"; }
194 protected boolean ignoreSingleton() { return false; }
198 // Ref //////////////////////////////////////////////////////////////////////////////
201 * This class represents a partially complete collection of
202 * forests to be viewed as a forest at some later date; once
203 * viewed, it becomes immutable
205 static class Ref<T> extends Forest<T> {
206 public void expand(TaskList tl, HashSet<Tree<T>> ht) {
207 for (Forest<T> f : hp) f.expand(tl, ht);
209 public void gather(TaskList tl, HashSet<Tree<T>>[] ht, HashSet<Tree<T>> target) {
212 public HashSet<GSS.Phase.Node> parents = new HashSet<GSS.Phase.Node>();
213 public boolean contains(Forest f) {
214 return hp.contains(f);
216 public boolean ambiguous() {
217 if (hp.size()==0) return false;
218 if (hp.size()==1) return hp.iterator().next().ambiguous();
221 private FastSet<Forest<T>> hp = new FastSet<Forest<T>>();
224 if (hp.size()==1) return hp.iterator().next().toInt();
225 return super.toInt();
227 public void merge(Forest p) { if (p!=this) hp.add(p, true); }
229 public boolean isTransparent() { return hp.size()==1; }
230 public boolean isHidden() { return hp.size()==0; }
231 public void edges(GraphViz.Node n) {
232 if (hp.size()==1) { hp.iterator().next().edges(n); return; }
233 for(Forest f : hp) f.edges(n);
235 public GraphViz.Node toGraphViz(GraphViz gv) {
236 //if (hp.size()==0) return null;
237 if (hp.size()==1) return hp.iterator().next().toGraphViz(gv);
238 if (gv.hasNode(this)) return gv.createNode(this);
239 GraphViz.Node n = gv.createNode(this);
242 for(Forest f : hp) n.edge(f, null);
246 public <B,C> void visit(Invokable<Forest.Body<T>,B,C> ivbc, B b, C c) {
247 if (hp==null) return;
248 for(Forest<T> f : hp)
251 public Forest resolve() { return this; }
254 public abstract <B,C> void visit(Invokable<Forest.Body<T>,B,C> ivbc, B b, C c);
256 // Statics //////////////////////////////////////////////////////////////////////////////
258 private static Tree[] tree_hint = new Tree[0];
259 private static String[] string_hint = new String[0];
260 private static final Forest[] emptyForestArray = new Forest[0];
262 protected String headToString() { return null; }
263 protected String headToJava() { return "null"; }
264 protected String left() { return "<?"; }
265 protected String right() { return "?>"; }
266 protected boolean ignoreSingleton() { return true; }