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 */
16 implements Invokable<Pos, ResultNode, Object>,
18 Iterable<ResultNode> {
20 /** which GSS.Phase this StateNode belongs to */
21 public GSS.Phase phase() { return phase; }
22 public Iterator<ResultNode> iterator() { return results.iterator(); }
23 public Parser.Table.State state() { return state; }
25 public int toInt() { return idx; }
27 boolean destroyed = false;
30 if (destroyed) return;
32 // - all nodes must have a predecessor
33 // - non-doomed nodes must either:
34 // - be on the frontier or
35 // - have a non-doomed node closer to the frontier than themself
36 if (phase.isFrontier()) dead = false;
37 else for(ResultNode r : successors)
38 if (state.doomed) { if (r.usedByAnyNode()) { dead = false; break; } }
39 else { if (r.usedByNonDoomedNode()) { dead = false; break; } }
40 dead |= results.size()==0;
43 if (phase() != null && phase().hash != null)
44 phase().hash.remove(state, predPhase);
45 while(successors.size()>0)
46 for(ResultNode r : successors) {
51 while(results.size()>0)
52 for(ResultNode r : results) {
61 //////////////////////////////////////////////////////////////////////
63 private static int node_idx = 0;
64 private final int idx = node_idx++;
66 private final GSS.Phase phase;
67 private final GSS.Phase predPhase;
68 private final Parser.Table.State state;
69 private boolean fromEmptyReduction;
70 private FastSet<ResultNode> results = new FastSet<ResultNode>();
71 private FastSet<ResultNode> successors = new FastSet<ResultNode>();
72 //private HashSet<ResultNode> results = new HashSet<ResultNode>();
73 //private HashSet<ResultNode> successors = new HashSet<ResultNode>();
75 public final void invoke(Pos r, ResultNode only, Object o) {
76 boolean emptyProductions = only==null;
77 if (emptyProductions != (r.numPops()==0)) return;
78 if (r.numPops()!=0) reduce(r, r.numPops()-1, phase(), only);
80 Input.Region region = phase().getLocation().createRegion(phase().getLocation());
81 phase().newNodeFromReduction(r.rewrite(region), r, this);
85 private void reduce(Pos r, int pos, GSS.Phase target, ResultNode only) {
86 for(ResultNode res : results)
87 if (only == null || res == only)
88 for(StateNode pred : res.getPreds())
89 reduce2(r, pos, target, pred, res.getForest());
92 void reduce2(Pos r, int pos, GSS.Phase target, StateNode pred, Forest f) {
93 Forest[] holder = r.holder;
94 Forest old = pos >= holder.length ? null : holder[pos];
95 if (pos < holder.length) holder[pos] = f;
96 if (pos>0) pred.reduce(r, pos-1, target, null);
98 Input.Region region = pred.phase().getLocation().createRegion(target.getLocation());
99 new Reduction(pred, r, r.rewrite(region), target);
101 if (pos < holder.length) holder[pos] = old;
104 StateNode(GSS.Phase phase, Forest f, Pos reduction, StateNode pred, State state, boolean fromEmptyReduction) {
105 this(phase, new ResultNode(f, reduction, pred), state, fromEmptyReduction);
107 StateNode(GSS.Phase phase, ResultNode pred, State state, boolean fromEmptyReduction) {
110 this.fromEmptyReduction = fromEmptyReduction;
111 if (phase.hash.get(state, pred.phase()) != null) throw new Error("severe problem!");
112 this.predPhase = pred.phase();
113 phase.hash.put(state, pred.phase(), this);
117 if (!fromEmptyReduction)
118 state.invokeReductions(phase().getToken(), this, pred);
120 state.invokeEpsilonReductions(phase().token, this);
123 // Add/Remove Successors/Results //////////////////////////////////////////////////////////////////////////////
125 public void removeSucc(ResultNode succ) {
126 successors.remove(succ);
129 public void removeResult(ResultNode result) {
130 results.remove(result);
133 public void addSucc(ResultNode succ) {
134 successors.add(succ);
136 public void addResult(Forest f, Pos reduction, StateNode pred) {
137 for(ResultNode r : results)
138 if (r.predecessorsContains(pred)) {
142 ResultNode result = new ResultNode(f, reduction, pred);
144 result.addSucc(this);
145 if (!this.fromEmptyReduction) state.invokeReductions(phase().getToken(), this, result);