1 package edu.berkeley.sbp;
2 import edu.berkeley.sbp.*;
3 import edu.berkeley.sbp.util.*;
4 import edu.berkeley.sbp.Parser.Table.*;
5 import edu.berkeley.sbp.Sequence.Position;
8 import java.lang.reflect.*;
10 /** implements Tomita's Graph Structured Stack */
15 private Phase.Node[] reducing_list = null;
16 public int resets = 0;
19 HashMapBag<Integer,Sequence> inhibited = new HashMapBag<Integer,Sequence>();
20 HashMapBag<Integer,Sequence> expectedInhibit = new HashMapBag<Integer,Sequence>();
21 HashMapBag<Sequence,Phase.Waiting> waiting = new HashMapBag<Sequence,Phase.Waiting>();
22 HashMapBag<Integer,Sequence> performed = new HashMapBag<Integer,Sequence>();
25 public Forest.Ref finalResult;
27 /** corresponds to a positions <i>between tokens</i> the input stream; same as Tomita's U_i's */
28 public class Phase<Tok> implements Invokable<State, Forest, Phase<Tok>.Node>, IntegerMappable {
30 public void invoke(State st, Forest result, Node n) {
31 good |= next.newNode(n, result, st, false);
34 /** the token immediately after this phase */
37 private final int pos;
40 private IntPairMap<Phase.Node> hash; /* ALLOC */
41 private IntPairMap<Forest> singularReductions; /* ALLOC */
42 private boolean closed;
44 private Phase next = null;
46 private Input.Location location;
47 public final Parser parser;
49 private Forest forest;
51 public Phase(Phase prev, Parser parser, Phase previous, Tok token, Input.Location location, Forest forest) {
55 this.pos = previous==null ? 0 : previous.pos+1;
57 this.location = location;
65 hash = new IntPairMap<Phase.Node>();
66 singularReductions = new IntPairMap<Forest>();
67 expectedInhibit.clear();
68 expectedInhibit.addAll(inhibited);
73 if (prev != null) prev.shift(this, forest);
77 public boolean isDone() throws ParseFailed {
78 if (token != null) return false;
79 if (token==null && finalResult==null)
80 throw new ParseFailed(ParseFailed.error(ANSI.red("unexpected end of file\n"), token, hash.values()), getLocation());
84 public Input.Location getLocation() { return location; }
86 /** add a new node (merging with existing nodes if possible)
87 * @param parent the parent of the new node
88 * @param result the SPPF result corresponding to the new node
89 * @param state the state that the new node is in
90 * @param fromEmptyReduction true iff this node is being created as a result of a reduction of length zero (see GRMLR paper)
91 * @param start the earliest part of the input contributing to this node (used to make merging decisions)
93 public boolean newNode(Node parent, Forest pending, State state, boolean fromEmptyReduction) {
94 Node p = hash.get(state, parent==null?null:parent.phase());
95 if (p != null) return newNode2(p, parent, pending, state, fromEmptyReduction);
96 else return newNode3(parent, pending, state, fromEmptyReduction);
98 public void newNode(Node parent, Forest pending, State state, boolean fromEmptyReduction, Position reduction) {
99 int pos = parent==null?0:parent.phase()==null?0:parent.phase().pos;
100 Sequence owner = reduction==null ? null : reduction.owner();
101 if (reduction!=null) {
102 if (inhibited.contains(pos, owner)) return;
103 if (owner.needs != null)
104 for(Sequence s : owner.needs)
105 if (!performed.contains(pos, s)) {
106 waiting.add(s, new Waiting(parent, pending, state, fromEmptyReduction, reduction));
109 if ((owner.needed != null && owner.needed.size()>0) ||
110 (owner.hated != null && owner.hated.size()>0) ||
111 (owner.hates != null && owner.hates.size()>0))
112 performed.add(pos, owner);
115 newNode(parent, pending, state, fromEmptyReduction);
116 if (reduction!=null) inhibit(reduction, parent==null?0:parent.phase().pos);
117 if (reduction != null) {
121 for(Waiting w : waiting.getAll(owner)) {
122 if (w.parent==parent || (parent!=null&&w.parent!=null&&w.parent.phase()==parent.phase())) {
123 waiting.remove(owner, w);
132 private boolean newNode2(Node p, Node parent, Forest pending, State state, boolean fromEmptyReduction) {
133 p.holder.merge(pending);
134 if (p.parents().contains(parent)) return true;
135 p.parents().add(parent, true);
136 if (p!=parent && !fromEmptyReduction && reducing) p.performReductions(parent);
139 private boolean newNode3(Node parent, Forest pending, State state, boolean fromEmptyReduction) {
141 if (token != null && state.canShift(token)) break;
142 if (state.isAccepting()) break;
143 if (token==null) break;
144 if (!state.canReduce(token)) return false;
145 //if (count > 1) break;
146 //if (r.numPop == 0) break;
147 //r.reduce(pending, parent, null, Phase.this, null);
151 Node n = new Node(parent, pending, state); // ALLOC
153 n.performEmptyReductions();
154 if (!fromEmptyReduction) n.performReductions(parent);
159 public void uninhibit(int p, Sequence s) {
161 for(Sequence s2 : s.hated)
162 inhibited.remove(p, s2);
165 public void inhibit(Position r, int p) {
166 if (r.owner().hated == null) return;
167 // remember that dead states are still allowed to shift -- just not allowed to reduce
168 boolean reset = false;
169 for(Sequence seq : r.owner().hated) {
170 if (performed.contains(p,seq)) {
172 //System.out.println("\nresetting due to " + r.owner() + " killing " + seq);
174 inhibited.add(p, seq);
175 //inhibited = new HashMapBag<Integer,Sequence>();
180 inhibited.add(p, seq);
181 expectedInhibit.remove(p, seq);
185 /** perform all reduction operations */
186 public void reduce() {
189 if (reducing_list==null || reducing_list.length < hash.size())
190 reducing_list = new Phase.Node[hash.size() * 4];
191 hash.toArray(reducing_list);
192 int num = hash.size();
193 for(int i=0; i<num; i++) {
194 Node n = reducing_list[i];
195 n.performEmptyReductions();
196 // INVARIANT: we never "see" a node until its parent-set is complete, modulo merges
198 for(int i=0; i<num; i++) {
199 Node n = reducing_list[i];
200 reducing_list[i] = null;
201 n.performReductions();
203 if (expectedInhibit.size() > 0) {
204 inhibited.removeAll(expectedInhibit);
205 System.out.println("\n!!!!\n");
214 class Reset extends RuntimeException { }
216 /** perform all shift operations, adding promoted nodes to <tt>next</tt> */
217 public void shift(Phase next, Forest result) throws ParseFailed {
218 // this massively improves GC performance
221 prev.singularReductions = null;
227 for(Phase.Node n : hash.values()) {
228 if (token == null && n.state.isAccepting()) {
229 if (finalResult==null) finalResult = new Forest.Ref();
230 finalResult.merge(n.holder);
232 if (token == null) continue;
233 n.state.invokeShifts(token, this, result, n);
236 if (!good && token!=null)
237 throw new ParseFailed(ParseFailed.error(ANSI.red("unexpected character")+" "+ANSI.purple(token)+" encountered at "+ANSI.green(getLocation())+"\n", token, hash.values()),
239 if (token==null && finalResult==null)
240 throw new ParseFailed(ParseFailed.error(ANSI.red("unexpected end of file\n"), token, hash.values()),
245 public class Waiting {
249 boolean fromEmptyReduction;
251 public Waiting(Node parent, Forest pending, State state, boolean fromEmptyReduction, Position reduction) {
253 this.parent = parent;
254 this.pending = pending;
256 this.fromEmptyReduction = fromEmptyReduction;
257 this.reduction = reduction;
259 public void perform() {
260 //System.out.println("performing: " + reduction.position);
261 newNode(parent, pending, state, fromEmptyReduction, reduction);
265 // Node /////////////////////////////////////////////////////////////////////////////////
267 /** a node in the GSS */
268 public final class Node extends FastSet<Node> implements Invokable<Position, Node, Node>, IntegerMappable {
270 private Forest.Ref holder = null;
271 private boolean allqueued = false;
273 /** what state this node is in */
274 public final Parser.Table<Tok>.State<Tok> state;
276 /** which Phase this Node belongs to (node that Node is also a non-static inner class of Phase) */
277 public Phase phase() { return Phase.this; }
278 public Forest.Ref holder() { return holder==null ? (holder = new Forest.Ref()) : holder; }
279 public Forest pending() { return Phase.this.closed ? holder().resolve() : holder; }
280 public FastSet<Node> parents() { return this; }
282 public void performReductions() {
283 if (allqueued) return;
285 state.invokeReductions(token, this, this, null);
288 public void performReductions(Node n2) {
289 if (!allqueued) performReductions();
290 else state.invokeReductions(token, this, this, n2);
293 public final void invoke(Position r, Node n, Node n2) {
294 if (n==null || n2==null || r.pos==0) {
296 if (n==null) n = this;
300 Forest[] holder = new Forest[r.pos];
301 if (r.pos==0) n.finish(r, r.zero(), n.phase(), holder);
302 else n.reduce(r, r.pos-1, n.phase(), holder);
304 Forest[] holder = new Forest[r.pos];
305 if (r.pos<=0) throw new Error("called wrong form of reduce()");
307 Forest old = holder[pos];
308 holder[pos] = n.pending();
310 System.arraycopy(holder, 0, r.holder, 0, holder.length);
312 if (r.pos==1) rex = singularReductions.get(this, r);
314 rex = r.rewrite(n.phase().getLocation());
315 if (r.pos==1) singularReductions.put(this, r, rex);
317 n2.finish(r, rex, n.phase(), holder);
319 n2.reduce(r, pos-1, n.phase(), holder);
325 public void reduce(Position r, int pos, Phase target, Forest[] holder) {
326 Forest old = holder[pos];
327 holder[pos] = this.pending();
329 System.arraycopy(holder, 0, r.holder, 0, holder.length);
330 for(int i=0; i<r.pos; i++) if (r.holder[i]==null) throw new Error("realbad");
332 if (r.pos==1) rex = singularReductions.get(this, r);
334 rex = r.rewrite(phase().getLocation());
335 if (r.pos==1) singularReductions.put(this, r, rex);
337 for(Node child : this.parents()) child.finish(r, rex, target, holder);
339 for(Node child : this.parents()) child.reduce(r, pos-1, target, holder);
344 public void finish(Position r, Forest result, Phase<Tok> target, Forest[] holder) {
345 Parser.Table<Tok>.State<Tok> state0 = state.gotoSetNonTerminals.get(r.owner());
346 if (result==null) throw new Error();
348 target.newNode(this, result, state0, r.pos<=0, r);
351 public void performEmptyReductions() { state.invokeReductions(token, this, null, null); }
353 private Node(Node parent, Forest pending, State state) {
355 this.holder().merge(pending);
356 Phase start = parent==null ? null : parent.phase();
357 if (parent != null) parents().add(parent, true);
358 if (Phase.this.hash.get(state, start) != null) throw new Error("severe problem!");
359 Phase.this.hash.put(state, start, this);
361 public int toInt() { return idx; }
362 private final int idx = node_idx++;
364 private int node_idx = 0;
366 public int toInt() { return pos+1; }
367 public int size() { return hash==null ? 0 : hash.size(); }