1 package edu.berkeley.sbp;
2 import edu.berkeley.sbp.*;
3 import edu.berkeley.sbp.util.*;
4 import edu.berkeley.sbp.Sequence.Position;
5 import edu.berkeley.sbp.Parser.Table.State;
6 import edu.berkeley.sbp.Parser.Table.Reduction;
9 import java.lang.reflect.*;
11 /** implements Tomita's Graph Structured Stack */
16 private Phase.Node[] reducing_list = null;
17 public int resets = 0;
20 HashMapBag<Integer,Sequence> inhibited = new HashMapBag<Integer,Sequence>();
21 HashMapBag<Integer,Sequence> assumed = new HashMapBag<Integer,Sequence>();
22 HashMapBag<Sequence,Phase.Waiting> waiting = new HashMapBag<Sequence,Phase.Waiting>();
23 HashMapBag<Integer,Sequence> performed = new HashMapBag<Integer,Sequence>();
24 HashSet<Phase.Waiting> tail = new HashSet<Phase.Waiting>();
26 /** corresponds to a positions <i>between tokens</i> the input stream; same as Tomita's U_i's */
27 public class Phase implements Invokable<State, Forest, GSS.Phase.Node> {
29 /** the token immediately after this phase */
30 public final Token token;
34 /** currently this is necessary only for the code() hack -- it doesn't actually correspond to the input */
35 private final int pos;
38 public Forest.Ref finalResult;
40 /** all nodes, keyed by the value returned by code() */
41 /*private*/ HashMap<Long,Phase.Node> hash; /* ALLOC */
43 /** the number of nodes in this phase */
49 private Phase next = null;
51 private Token.Location location;
52 public final Parser parser;
54 private Forest forest;
56 public Phase(Phase prev, Parser parser, Phase previous, Token token, Token.Location location, Forest forest) {
60 this.pos = previous==null ? 0 : previous.pos+1;
62 this.location = location;
72 hash = new HashMap<Long,Phase.Node>();
78 if (prev != null) prev.shift(this, forest);
81 public void complain(Node n, HashMap<String,HashSet<String>> errors, boolean force) {
82 if (n.touched) return;
84 for(Position p : n.state) {
86 if (((p.isFirst() || p.isLast()) && !force) || p.owner().name==null) {
87 for(Node n2 : n.parents())
88 complain(n2, errors, force | p.isFirst());
90 String seqname = p.owner().name;
91 HashSet<String> hs = errors.get(seqname);
92 if (hs==null) errors.put(seqname, hs = new HashSet<String>());
93 hs.add(p.element()+"");
94 //String s = " while parsing " + seqname + ": expected a " + p.element();
98 for(Position p2 = p.owner().firstp(); p2 != null && p2 != p && !p2.isLast(); p2 = p2.next()) s += (p2.element() + " ");
101 for(Position p2 = p; p2 != null && !p2.isLast(); p2 = p2.next()) s += (p2.element() + " ");
109 public String black(Object o) { return "\033[30m"+o+"\033[0m"; }
110 public String red(Object o) { return "\033[31m"+o+"\033[0m"; }
111 public String green(Object o) { return "\033[32m"+o+"\033[0m"; }
112 public String yellow(Object o) { return "\033[33m"+o+"\033[0m"; }
113 public String blue(Object o) { return "\033[34m"+o+"\033[0m"; }
114 public String purple(Object o) { return "\033[35m"+o+"\033[0m"; }
115 public String cyan(Object o) { return "\033[36m"+o+"\033[0m"; }
116 public String el(Object e) {
117 String s = e.toString();
118 if (s.length()==0 || s.charAt(0)!='\"' || s.charAt(s.length()-1)!='\"') return yellow(s);
120 s = s.substring(0, s.length()-1);
121 StringBuffer ret = new StringBuffer();
122 for(int i=0; i<s.length(); i++) {
123 if (s.charAt(i)=='\\' && i<s.length()-1) ret.append(s.charAt(++i));
126 return purple(ret.toString());
128 public String error(String message) {
129 String lookAhead = token==null ? "<EOF>" : token.toString();
130 StringBuffer ret = new StringBuffer();
133 HashMap<String,HashSet<String>> errors = new HashMap<String,HashSet<String>>();
134 for(Node n : hash.values()) complain(n, errors, false);
135 for(String s : errors.keySet()) {
136 ret.append(" while parsing " + yellow(s));
137 HashSet<String> hs = errors.get(s);
138 if (hs.size()==1) ret.append(" expected " + yellow(el(hs.iterator().next())) + "\n");
140 ret.append(" expected ");
141 boolean first = true;
142 for(String s2 : hs) {
143 if (!first) ret.append(" or ");
145 ret.append(yellow(el(s2)));
150 return ret.toString();
153 public boolean isDone() throws Parser.Failed {
154 if (token != null) return false;
155 if (token==null && finalResult==null)
156 throw new Parser.Failed(error(red("unexpected end of file\n")),
161 public Token.Location getLocation() { return location; }
163 /** add a new node (merging with existing nodes if possible)
164 * @param parent the parent of the new node
165 * @param result the SPPF result corresponding to the new node
166 * @param state the state that the new node is in
167 * @param fromEmptyReduction true iff this node is being created as a result of a reduction of length zero (see GRMLR paper)
168 * @param start the earliest part of the input contributing to this node (used to make merging decisions)
170 public boolean newNode(Node parent, Forest pending, State state, boolean fromEmptyReduction) {
171 Node p = hash.get(code(state, parent==null?null:parent.phase()));
172 if (p != null) return newNode2(p, parent, pending, state, fromEmptyReduction);
173 else return newNode3(parent, pending, state, fromEmptyReduction);
175 public void newNode(Node parent, Forest pending, State state, boolean fromEmptyReduction, Reduction reduction) {
176 int pos = parent==null?0:parent.phase()==null?0:parent.phase().pos;
177 Sequence owner = reduction==null ? null : reduction.position.owner();
178 if (reduction!=null) {
179 if (inhibited.contains(pos, owner)) return;
181 if (assumed.contains(pos, owner)) {
182 tail.add(new Waiting(parent, pending, state, fromEmptyReduction, reduction));
186 if (owner.needs != null)
187 for(Sequence s : owner.needs)
188 if (!performed.contains(pos, s)) {
189 waiting.add(s, new Waiting(parent, pending, state, fromEmptyReduction, reduction));
192 if ((owner.needed != null && owner.needed.size()>0) ||
193 (owner.hated != null && owner.hated.size()>0) ||
194 (owner.hates != null && owner.hates.size()>0))
195 performed.add(pos, owner);
198 newNode(parent, pending, state, fromEmptyReduction);
199 if (reduction!=null) inhibit(reduction, parent==null?0:parent.phase().pos);
200 if (reduction != null) {
204 for(Waiting w : waiting.getAll(owner)) {
205 if (w.parent==parent || (parent!=null&&w.parent!=null&&w.parent.phase()==parent.phase())) {
206 waiting.remove(owner, w);
215 private boolean newNode2(Node p, Node parent, Forest pending, State state, boolean fromEmptyReduction) {
216 p.holder.merge(pending);
217 if (p.parents().contains(parent)) return true;
218 p.parents().add(parent, true);
219 if (p!=parent && !fromEmptyReduction) p.queueReductions(parent);
222 private boolean newNode3(Node parent, Forest pending, State state, boolean fromEmptyReduction) {
224 if (token != null && state.canShift(token)) break;
225 if (state.isAccepting()) break;
226 if (token==null) break;
227 //if (!state.canReduce(token)) return false;
228 //if (count > 1) break;
229 //if (r.numPop == 0) break;
230 //r.reduce(pending, parent, null, Phase.this, null);
234 Node n = new Node(parent, pending, state, fromEmptyReduction); // ALLOC
235 n.queueEmptyReductions();
236 if (!fromEmptyReduction) n.queueReductions(parent);
240 public void uninhibit(int p, Sequence s) {
242 for(Sequence s2 : s.hated)
243 inhibited.remove(p, s2);
246 public void inhibit(Reduction r, int p) {
247 if (r.position.owner().hated == null) return;
248 // remember that dead states are still allowed to shift -- just not allowed to reduce
249 boolean reset = false;
250 for(Sequence seq : r.position.owner().hated) {
251 if (performed.contains(p,seq)) {
253 //System.out.println("\nresetting due to " + r.position.owner() + " killing " + seq);
255 inhibited.add(p, seq);
256 //assumed = inhibited;
257 //inhibited = new HashMapBag<Integer,Sequence>();
262 inhibited.add(p, seq);
266 /** perform all reduction operations */
267 public void reduce() {
270 if (reducing_list==null || reducing_list.length < hash.size())
271 reducing_list = new Phase.Node[hash.size() * 4];
272 Collection<Node> hv = hash.values();
273 hv.toArray(reducing_list);
275 for(int i=0; i<num; i++) {
276 Node n = reducing_list[i];
277 n.queueEmptyReductions();
278 // INVARIANT: we never "see" a node until its parent-set is complete, modulo merges
280 for(int i=0; i<num; i++) {
281 Node n = reducing_list[i];
282 reducing_list[i] = null;
285 //for(Waiting w : tail)
293 class Reset extends RuntimeException { }
295 public void invoke(State st, Forest result, Node n) {
296 good |= next.newNode(n, result, st, false);
299 /** perform all shift operations, adding promoted nodes to <tt>next</tt> */
300 public void shift(Phase next, Forest result) throws Parser.Failed {
301 if (prev!=null) prev.hash = null;
306 for(Phase.Node n : hash.values()) {
307 //if (n.holder().empty() && pos>0) continue;
308 if (token == null && n.state.isAccepting()) {
309 if (finalResult==null) finalResult = new Forest.Ref();
310 finalResult.merge(n.holder);
312 if (token == null) continue;
313 n.state.invokeShifts(token, this, result, n);
316 if (!good && token!=null)
317 throw new Parser.Failed(error(red("unexpected character")+" "+purple(token)+" encountered at "+green(getLocation())+"\n"),
319 if (token==null && finalResult==null)
320 throw new Parser.Failed(error(red("unexpected end of file\n")),
323 // this massively improves GC performance
328 public class Waiting {
332 boolean fromEmptyReduction;
334 public Waiting(Node parent, Forest pending, State state, boolean fromEmptyReduction, Reduction reduction) {
336 this.parent = parent;
337 this.pending = pending;
339 this.fromEmptyReduction = fromEmptyReduction;
340 this.reduction = reduction;
342 public void perform() {
343 //System.out.println("performing: " + reduction.position);
344 newNode(parent, pending, state, fromEmptyReduction, reduction);
348 // GSS Nodes //////////////////////////////////////////////////////////////////////////////
350 /** a node in the GSS */
351 public final class Node extends FastSet<Node> implements Invokable<Reduction, Node, Node> {
353 public boolean touched = false;
354 private Forest.Ref holder = null;
355 private boolean allqueued = false;
357 /** what state this node is in */
358 public final State state;
360 /** which Phase this Node belongs to (node that Node is also a non-static inner class of Phase) */
361 public Phase phase() { return Phase.this; }
363 public Forest.Ref holder() { return holder==null ? (holder = new Forest.Ref()) : holder; }
364 public Forest pending() { return Phase.this.closed ? holder().resolve() : holder; }
365 public FastSet<Node> parents() { return this; }
367 public void queueReductions() {
368 if (!reducing) return;
369 if (allqueued) return;
371 int where = parents().size();
372 state.invokeReductions(token, this, this, null);
375 public void queueReductions(Node n2) {
376 if (!allqueued) { queueReductions(); return; }
377 state.invokeReductions(token, this, this, n2);
380 public final void invoke(Reduction r, Node n, Node n2) {
382 if (r.numPop==0) r.reduce(this);
385 if (r.numPop==0) return;
386 if (n2==null) r.reduce(n);
387 else r.reduce(n, n2);
389 public void queueEmptyReductions() {
390 if (!reducing) return;
391 state.invokeReductions(token, this, null, null);
395 public boolean dead = false;
396 public boolean redo = false;
397 private Node(Node parent, Forest pending, State state, boolean fe) {
400 this.holder().merge(pending);
401 //if (holder().empty()) throw new Error(holder()+"");
402 Phase start = parent==null ? null : parent.phase();
403 if (parent != null) parents().add(parent, true);
404 if (Phase.this.hash.get(code(state, start)) != null) throw new Error("severe problem!");
405 Phase.this.hash.put(code(state, start), this);
406 Phase.this.numNodes++;
413 private static boolean equal(Object a, Object b) {
414 if (a==null && b==null) return true;
415 if (a==null || b==null) return false;
419 /** this is something of a hack right now */
420 private static long code(State state, Phase start) {
421 return (((long)state.idx) << 32) | (start==null ? 0 : (start.pos+1));