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 */
13 public static int count = 0;
16 private Phase.Node[] reducing_list = null;
17 public int resets = 0;
20 HashMapBag<Sequence,Phase.Waiting> waiting = new HashMapBag<Sequence,Phase.Waiting>();
21 HashMapBag<Integer,Sequence> performed = new HashMapBag<Integer,Sequence>();
22 HashMapBag<Integer,Sequence> lastperformed = new HashMapBag<Integer,Sequence>();
23 HashMapBag<Integer,Sequence> expected = new HashMapBag<Integer,Sequence>();
26 public Forest.Ref finalResult;
28 /** corresponds to a positions <i>between tokens</i> the input stream; same as Tomita's U_i's */
29 class Phase<Tok> implements Invokable<State, Forest, Phase<Tok>.Node>, IntegerMappable {
31 public void invoke(State st, Forest result, Node n) {
32 good |= next.newNode(n, result, st, false);
35 /** the token immediately after this phase */
38 private final int pos;
41 private IntPairMap<Phase.Node> hash; /* ALLOC */
42 private IntPairMap<Forest> singularReductions; /* ALLOC */
43 private boolean closed;
45 private Phase next = null;
47 private Input.Location location;
48 public final Parser parser;
50 private Forest forest;
52 public Phase(Phase prev, Parser parser, Phase previous, Tok token, Input.Location location, Forest forest) throws ParseFailed {
56 this.pos = previous==null ? 0 : previous.pos+1;
58 this.location = location;
63 public void reset() throws ParseFailed {
66 lastperformed.clear();
67 lastperformed.addAll(performed);
69 hash = new IntPairMap<Phase.Node>();
70 singularReductions = new IntPairMap<Forest>();
76 if (prev != null) prev.shift(this, forest);
80 public boolean isDone() throws ParseFailed {
81 if (token != null) return false;
82 if (token==null && finalResult==null)
83 throw new ParseFailed(ParseFailed.error(ANSI.red("unexpected end of file\n"), token, hash.values()), getLocation());
87 public Input.Location getLocation() { return location; }
89 /** add a new node (merging with existing nodes if possible)
90 * @param parent the parent of the new node
91 * @param result the SPPF result corresponding to the new node
92 * @param state the state that the new node is in
93 * @param fromEmptyReduction true iff this node is being created as a result of a reduction of length zero (see GRMLR paper)
94 * @param start the earliest part of the input contributing to this node (used to make merging decisions)
96 public boolean newNode(Node parent, Forest pending, State state, boolean fromEmptyReduction) {
97 Node p = hash.get(state, parent==null?null:parent.phase());
98 if (p != null) return newNode2(p, parent, pending, state, fromEmptyReduction);
99 else return newNode3(parent, pending, state, fromEmptyReduction);
101 public void newNode(Node parent, Forest pending, State state, boolean fromEmptyReduction, Position reduction) {
102 int pos = parent==null?0:parent.phase()==null?0:parent.phase().pos;
103 Sequence owner = reduction==null ? null : reduction.owner();
104 if (reduction!=null) {
105 if (owner.hates!=null) {
106 for (Sequence s : performed.getAll(pos))
107 if (owner.hates.contains(s))
109 for (Sequence s : lastperformed.getAll(pos))
110 if (owner.hates.contains(s)) {
111 //System.out.println("now expecting ["+pos+"] => " + s);
112 expected.add(pos, s);
116 if (owner.needs != null)
117 for(Sequence s : owner.needs)
118 if (!performed.contains(pos, s)) {
119 waiting.add(s, new Waiting(parent, pending, state, fromEmptyReduction, reduction));
122 if (!performed.contains(pos, owner)) {
123 performed.add(pos, owner);
124 if (owner.hated != null)
125 for(Sequence seq : owner.hated)
126 if (performed.contains(pos, seq)) {
127 performed.remove(pos, seq);
133 newNode(parent, pending, state, fromEmptyReduction);
134 if (reduction != null) {
138 for(Waiting w : waiting.getAll(owner)) {
139 if (w.parent==parent || (parent!=null&&w.parent!=null&&w.parent.phase()==parent.phase())) {
140 waiting.remove(owner, w);
149 private boolean newNode2(Node p, Node parent, Forest pending, State state, boolean fromEmptyReduction) {
150 p.holder.merge(pending);
151 if (p.parents().contains(parent)) return true;
152 p.parents().add(parent, true);
153 if (p!=parent && !fromEmptyReduction && reducing) p.performReductions(parent);
156 private boolean newNode3(Node parent, Forest pending, State state, boolean fromEmptyReduction) {
158 if (token != null && state.canShift(token)) break;
159 if (state.isAccepting()) break;
160 if (token==null) break;
161 if (!state.canReduce(token)) return false;
162 //if (count > 1) break;
163 //if (r.numPop == 0) break;
164 //r.reduce(pending, parent, null, Phase.this, null);
168 Node n = new Node(parent, pending, state); // ALLOC
170 n.performEmptyReductions();
171 if (!fromEmptyReduction) n.performReductions(parent);
176 /** perform all reduction operations */
177 public void reduce() throws ParseFailed {
180 if (reducing_list==null || reducing_list.length < hash.size())
181 reducing_list = new Phase.Node[hash.size() * 4];
182 hash.toArray(reducing_list);
183 int num = hash.size();
184 for(int i=0; i<num; i++) {
185 Node n = reducing_list[i];
186 n.performEmptyReductions();
187 // INVARIANT: we never "see" a node until its parent-set is complete, modulo merges
189 for(int i=0; i<num; i++) {
190 Node n = reducing_list[i];
191 reducing_list[i] = null;
192 n.performReductions();
199 for(int i : expected)
200 for(Sequence s : expected.getAll(i))
201 if (!performed.contains(i, s)) {
202 //System.out.println("resetting due to pos="+i+": " + s + " " + System.identityHashCode(s));
213 private boolean reset = false;
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 ")+" \'"+
238 ANSI.purple(StringUtil.escapify(token+"", "\\\'\r\n"))+
239 "\' encountered at "+
240 ANSI.green(getLocation())+"\n", token, hash.values()),
242 if (token==null && finalResult==null)
243 throw new ParseFailed(ParseFailed.error(ANSI.red("unexpected end of file\n"), token, hash.values()),
252 boolean fromEmptyReduction;
254 public Waiting(Node parent, Forest pending, State state, boolean fromEmptyReduction, Position reduction) {
256 this.parent = parent;
257 this.pending = pending;
259 this.fromEmptyReduction = fromEmptyReduction;
260 this.reduction = reduction;
262 public void perform() {
263 //System.out.println("performing: " + reduction.position);
264 newNode(parent, pending, state, fromEmptyReduction, reduction);
268 // Node /////////////////////////////////////////////////////////////////////////////////
270 /** a node in the GSS */
271 final class Node extends FastSet<Node> implements Invokable<Position, Node, Node>, IntegerMappable {
273 private Forest.Ref holder = null;
274 private boolean allqueued = false;
276 /** what state this node is in */
277 public final Parser.Table<Tok>.State<Tok> state;
279 /** which Phase this Node belongs to (node that Node is also a non-static inner class of Phase) */
280 public Phase phase() { return Phase.this; }
281 public Forest.Ref holder() { return holder==null ? (holder = new Forest.Ref()) : holder; }
282 public Forest pending() { return Phase.this.closed ? holder().resolve() : holder; }
283 public FastSet<Node> parents() { return this; }
285 public void performReductions() {
286 if (allqueued) return;
288 state.invokeReductions(token, this, this, null);
291 public void performReductions(Node n2) {
292 if (!allqueued) performReductions();
293 else state.invokeReductions(token, this, this, n2);
296 public void performEmptyReductions() { state.invokeReductions(token, this, null, null); }
297 public final void invoke(Position r, Node n, Node n2) {
298 if (n==null || n2==null || r.pos==0) {
300 if (n==null) n = this;
304 Forest[] holder = new Forest[r.pos];
305 if (r.pos==0) n.finish(r, r.zero(), n.phase(), holder);
306 else n.reduce(r, r.pos-1, n.phase(), holder);
308 Forest[] holder = new Forest[r.pos];
309 if (r.pos<=0) throw new Error("called wrong form of reduce()");
311 n.reduce(r, pos, n.phase(), holder, n2);
315 public void reduce(Position r, int pos, Phase target, Forest[] holder) { reduce(r, pos, target, holder, null); }
316 public void reduce(Position r, int pos, Phase target, Forest[] holder, Node only) {
317 Forest old = holder[pos];
318 holder[pos] = this.pending();
320 System.arraycopy(holder, 0, r.holder, 0, holder.length);
321 for(int i=0; i<r.pos; i++) if (r.holder[i]==null) throw new Error("realbad");
324 // FIXME: I'm unsure about this -- basically we want to deal with the case where
325 // there are two nodes, each of whose Ref points to the same Forest instance.
326 // Some node in the next phase has both of these as parents. This might happen
327 // since the same reduction can appear in more than one state.
328 if (r.pos==1) rex = singularReductions.get(this.pending(), r);
330 rex = r.rewrite(phase().getLocation());
331 if (r.pos==1) singularReductions.put(this.pending(), r, rex);
333 if (only != null) only.finish(r, rex, target, holder);
334 else for(Node child : this.parents()) child.finish(r, rex, target, holder);
336 if (only != null) only.reduce(r, pos-1, target, holder);
337 else for(Node child : this.parents()) child.reduce(r, pos-1, target, holder);
342 public void finish(Position r, Forest result, Phase<Tok> target, Forest[] holder) {
343 Parser.Table<Tok>.State<Tok> state0 = state.gotoSetNonTerminals.get(r.owner());
344 if (result==null) throw new Error();
346 target.newNode(this, result, state0, r.pos<=0, r);
349 private Node(Node parent, Forest pending, State state) {
351 this.holder().merge(pending);
352 Phase start = parent==null ? null : parent.phase();
353 if (parent != null) parents().add(parent, true);
354 if (Phase.this.hash.get(state, start) != null) throw new Error("severe problem!");
355 Phase.this.hash.put(state, start, this);
357 public int toInt() { return idx; }
358 private final int idx = node_idx++;
360 private int node_idx = 0;
362 public int toInt() { return pos+1; }
363 public int size() { return hash==null ? 0 : hash.size(); }