1 // Copyright 2006-2007 all rights reserved; see LICENSE file for BSD-style license
3 package edu.berkeley.sbp;
4 import edu.berkeley.sbp.*;
5 import edu.berkeley.sbp.util.*;
6 import edu.berkeley.sbp.Parser.Table.*;
7 import edu.berkeley.sbp.Sequence.Pos;
8 import edu.berkeley.sbp.Sequence.Pos;
11 import java.lang.reflect.*;
13 /** a node in the GSS */
15 extends Node<ResultNode>
16 implements Invokable<Pos, ResultNode, Object>,
17 Iterable<ResultNode> {
19 /** which GSS.Phase this StateNode belongs to */
20 public GSS.Phase phase() { return phase; }
21 public Iterator<ResultNode> iterator() { return predecessors.iterator(); }
22 public Parser.Table.State state() { return state; }
24 boolean destroyed = false;
27 if (destroyed) return;
29 // - all nodes must have a predecessor
30 // - non-doomed nodes must either:
31 // - be on the frontier or
32 // - have a non-doomed node closer to the frontier than themself
33 if (phase.isFrontier()) dead = false;
34 else for(ResultNode r : successors)
35 if (state.doomed) { if (r.usedByAnyNode()) { dead = false; break; } }
36 else { if (r.usedByNonDoomedNode()) { dead = false; break; } }
37 dead |= predecessors.size()==0;
40 if (phase() != null && phase().hash != null)
41 phase().hash.remove(state, predPhase);
42 while(successors.size()>0)
43 for(ResultNode r : successors) {
48 while(predecessors.size()>0)
49 for(ResultNode r : predecessors) {
50 predecessors.remove(r);
58 //////////////////////////////////////////////////////////////////////
60 private final GSS.Phase phase;
61 private final GSS.Phase predPhase;
62 private final Parser.Table.State state;
63 private boolean fromEmptyReduction;
64 private FastSet<ResultNode> predecessors = new FastSet<ResultNode>();
65 private FastSet<ResultNode> successors = new FastSet<ResultNode>();
66 //private HashSet<ResultNode> predecessors = new HashSet<ResultNode>();
67 //private HashSet<ResultNode> successors = new HashSet<ResultNode>();
69 public final void invoke(Pos r, ResultNode only, Object o) {
70 boolean emptyProductions = only==null;
71 if (emptyProductions != (r.numPops()==0)) return;
72 if (r.numPops()!=0) reduce(r, r.numPops()-1, phase(), only);
74 Input.Region region = phase().getLocation().createRegion(phase().getLocation());
75 phase().newNodeFromReduction(r.rewrite(region), r, this);
79 private void reduce(Pos r, int pos, GSS.Phase target, ResultNode only) {
80 for(ResultNode res : predecessors)
81 if (only == null || res == only)
82 for(StateNode pred : res.getPreds())
83 reduce2(r, pos, target, pred, res.getForest());
86 void reduce2(Pos r, int pos, GSS.Phase target, StateNode pred, Forest f) {
87 Forest[] holder = r.holder;
88 Forest old = pos >= holder.length ? null : holder[pos];
89 if (pos < holder.length) holder[pos] = f;
90 if (pos>0) pred.reduce(r, pos-1, target, null);
92 Input.Region region = pred.phase().getLocation().createRegion(target.getLocation());
93 new Reduction(pred, r, r.rewrite(region), target);
95 if (pos < holder.length) holder[pos] = old;
98 StateNode(GSS.Phase phase, Forest f, Pos reduction, StateNode pred, State state, boolean fromEmptyReduction) {
99 this(phase, new ResultNode(f, reduction, pred), state, fromEmptyReduction);
101 StateNode(GSS.Phase phase, ResultNode pred, State state, boolean fromEmptyReduction) {
104 this.fromEmptyReduction = fromEmptyReduction;
105 if (phase.hash.get(state, pred.phase()) != null) throw new Error("severe problem!");
106 this.predPhase = pred.phase();
107 phase.hash.put(state, pred.phase(), this);
109 predecessors.add(pred);
111 if (!fromEmptyReduction)
112 state.invokeReductions(phase().getToken(), this, pred);
114 state.invokeEpsilonReductions(phase().token, this);
117 // Add/Remove Successors/Predecessors //////////////////////////////////////////////////////////////////////////////
119 public void removeSucc(ResultNode succ) {
120 successors.remove(succ);
123 public void removeResult(ResultNode result) {
124 predecessors.remove(result);
127 public void addSucc(ResultNode succ) {
128 successors.add(succ);
130 public void addResult(Forest f, Pos reduction, StateNode pred) {
131 for(ResultNode r : predecessors)
132 if (r.predecessorsContains(pred)) {
136 ResultNode result = new ResultNode(f, reduction, pred);
137 predecessors.add(result);
138 result.addSucc(this);
139 if (!this.fromEmptyReduction) state.invokeReductions(phase().getToken(), this, result);