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<Sequence,Phase.Waiting> waiting = new HashMapBag<Sequence,Phase.Waiting>();
22 HashMapBag<Integer,Sequence> performed = new HashMapBag<Integer,Sequence>();
24 /** corresponds to a positions <i>between tokens</i> the input stream; same as Tomita's U_i's */
25 public class Phase implements Invokable<State, Forest, GSS.Phase.Node> {
27 /** the token immediately after this phase */
28 public final Token token;
32 /** currently this is necessary only for the code() hack -- it doesn't actually correspond to the input */
33 private final int pos;
36 public Forest.Ref finalResult;
38 /** all nodes, keyed by the value returned by code() */
39 /*private*/ HashMap<Long,Phase.Node> hash; /* ALLOC */
41 /** the number of nodes in this phase */
47 private Phase next = null;
49 private Token.Location location;
50 public final Parser parser;
52 private Forest forest;
54 public Phase(Phase prev, Parser parser, Phase previous, Token token, Token.Location location, Forest forest) {
58 this.pos = previous==null ? 0 : previous.pos+1;
60 this.location = location;
68 hash = new HashMap<Long,Phase.Node>();
74 if (prev != null) prev.shift(this, forest);
77 public void complain(Node n, HashMap<String,HashSet<String>> errors, boolean force) {
78 if (n.touched) return;
80 for(Position p : n.state) {
82 if (((p.isFirst() || p.isLast()) && !force) || p.owner().name==null) {
83 for(Node n2 : n.parents())
84 complain(n2, errors, force | p.isFirst());
86 String seqname = p.owner().name;
87 HashSet<String> hs = errors.get(seqname);
88 if (hs==null) errors.put(seqname, hs = new HashSet<String>());
89 hs.add(p.element()+"");
90 //String s = " while parsing " + seqname + ": expected a " + p.element();
94 for(Position p2 = p.owner().firstp(); p2 != null && p2 != p && !p2.isLast(); p2 = p2.next()) s += (p2.element() + " ");
97 for(Position p2 = p; p2 != null && !p2.isLast(); p2 = p2.next()) s += (p2.element() + " ");
105 public String black(Object o) { return "\033[30m"+o+"\033[0m"; }
106 public String red(Object o) { return "\033[31m"+o+"\033[0m"; }
107 public String green(Object o) { return "\033[32m"+o+"\033[0m"; }
108 public String yellow(Object o) { return "\033[33m"+o+"\033[0m"; }
109 public String blue(Object o) { return "\033[34m"+o+"\033[0m"; }
110 public String purple(Object o) { return "\033[35m"+o+"\033[0m"; }
111 public String cyan(Object o) { return "\033[36m"+o+"\033[0m"; }
112 public String el(Object e) {
113 String s = e.toString();
114 if (s.length()==0 || s.charAt(0)!='\"' || s.charAt(s.length()-1)!='\"') return yellow(s);
116 s = s.substring(0, s.length()-1);
117 StringBuffer ret = new StringBuffer();
118 for(int i=0; i<s.length(); i++) {
119 if (s.charAt(i)=='\\' && i<s.length()-1) ret.append(s.charAt(++i));
122 return purple(ret.toString());
124 public String error(String message) {
125 String lookAhead = token==null ? "<EOF>" : token.toString();
126 StringBuffer ret = new StringBuffer();
129 HashMap<String,HashSet<String>> errors = new HashMap<String,HashSet<String>>();
130 for(Node n : hash.values()) complain(n, errors, false);
131 for(String s : errors.keySet()) {
132 ret.append(" while parsing " + yellow(s));
133 HashSet<String> hs = errors.get(s);
134 if (hs.size()==1) ret.append(" expected " + yellow(el(hs.iterator().next())) + "\n");
136 ret.append(" expected ");
137 boolean first = true;
138 for(String s2 : hs) {
139 if (!first) ret.append(" or ");
141 ret.append(yellow(el(s2)));
146 return ret.toString();
149 public boolean isDone() throws Parser.Failed {
150 if (token != null) return false;
151 if (token==null && finalResult==null)
152 throw new Parser.Failed(error(red("unexpected end of file\n")),
157 public Token.Location getLocation() { return location; }
159 /** add a new node (merging with existing nodes if possible)
160 * @param parent the parent of the new node
161 * @param result the SPPF result corresponding to the new node
162 * @param state the state that the new node is in
163 * @param fromEmptyReduction true iff this node is being created as a result of a reduction of length zero (see GRMLR paper)
164 * @param start the earliest part of the input contributing to this node (used to make merging decisions)
166 public boolean newNode(Node parent, Forest pending, State state, boolean fromEmptyReduction) {
167 return newNode(parent, pending, state, fromEmptyReduction, null); }
168 public boolean newNode(Node parent, Forest pending, State state, boolean fromEmptyReduction, Reduction reduction) {
169 int pos = parent==null?0:parent.phase()==null?0:parent.phase().pos;
170 if (reduction!=null) {
171 if (inhibited.contains(pos, reduction.position.owner())) return false;
172 if (reduction.position.owner().needs != null) {
173 for(Sequence s : reduction.position.owner().needs) {
174 if (!performed.contains(pos, s)) {
175 waiting.add(s, new Waiting(parent, pending, state, fromEmptyReduction, reduction));
180 if ((reduction.position.owner().needed != null && reduction.position.owner().needed.size()>0) ||
181 (reduction.position.owner().hated != null && reduction.position.owner().hated.size()>0) ||
182 (reduction.position.owner().hates != null && reduction.position.owner().hates.size()>0))
183 performed.add(pos, reduction.position.owner());
185 Node p = hash.get(code(state, parent==null?null:parent.phase()));
187 if (reduction!=null) inhibit(reduction, parent==null?0:parent.phase().pos);
188 if (p != null) ret = newNode2(p, parent, pending, state, fromEmptyReduction, reduction);
189 else ret = newNode3(parent, pending, state, fromEmptyReduction, reduction);
190 if (reduction != null) {
194 for(Waiting w : waiting.getAll(reduction.position.owner())) {
195 if (w.parent==parent || (parent!=null&&w.parent!=null&&w.parent.phase()==parent.phase())) {
196 waiting.remove(reduction.position.owner(), w);
206 private boolean newNode2(Node p, Node parent, Forest pending, State state, boolean fromEmptyReduction, Reduction reduction) {
207 p.holder.merge(pending);
208 if (p.parents().contains(parent)) return true;
209 //if (p.fe && p.phase() != parent.phase()) throw new Error("yep yep");
210 //if (!p.fe && p.phase() == parent.phase()) throw new Error("yep yep2");
211 p.parents().add(parent, true);
212 if (p!=parent && !fromEmptyReduction) p.queueReductions(parent);
215 private boolean newNode3(Node parent, Forest pending, State state, boolean fromEmptyReduction, Reduction reduction) {
217 if (token != null && state.canShift(token)) break;
218 if (state.isAccepting()) break;
219 if (token==null) break;
220 //if (!state.canReduce(token)) return false;
221 //if (count > 1) break;
222 //if (r.numPop == 0) break;
223 //r.reduce(pending, parent, null, Phase.this, null);
227 Node n = new Node(parent, pending, state, fromEmptyReduction); // ALLOC
228 n.queueEmptyReductions();
229 if (!fromEmptyReduction) n.queueReductions(parent);
233 public void uninhibit(int p, Sequence s) {
235 for(Sequence s2 : s.hated)
236 inhibited.remove(p, s2);
239 public void inhibit(Reduction r, int p) {
240 if (r.position.owner().hated == null) return;
241 // remember that dead states are still allowed to shift -- just not allowed to reduce
242 boolean reset = false;
243 for(Sequence seq : r.position.owner().hated) {
244 if (performed.contains(p,seq)) {
246 //System.out.println("\nresetting due to " + r.position.owner() + " killing " + seq);
247 if (!reset) inhibited.add(p, seq);
250 if (!reset) inhibited.add(p, seq);
258 /** perform all reduction operations */
259 public void reduce() {
262 if (reducing_list==null || reducing_list.length < hash.size())
263 reducing_list = new Phase.Node[hash.size() * 4];
264 Collection<Node> hv = hash.values();
265 hv.toArray(reducing_list);
267 for(int i=0; i<num; i++) {
268 Node n = reducing_list[i];
269 n.queueEmptyReductions();
270 // INVARIANT: we never "see" a node until its parent-set is complete, modulo merges
272 for(int i=0; i<num; i++) {
273 Node n = reducing_list[i];
274 reducing_list[i] = null;
283 class Reset extends RuntimeException { }
285 public void invoke(State st, Forest result, Node n) {
286 good |= next.newNode(n, result, st, false);
289 /** perform all shift operations, adding promoted nodes to <tt>next</tt> */
290 public void shift(Phase next, Forest result) throws Parser.Failed {
291 if (prev!=null) prev.hash = null;
296 for(Phase.Node n : hash.values()) {
297 if (n.holder==null) continue;
299 if (token == null && n.state.isAccepting()) {
300 if (finalResult==null) finalResult = new Forest.Ref();
301 finalResult.merge(n.holder);
303 if (!n.holder.valid()) continue;
304 if (token == null) continue;
305 n.state.invokeShifts(token, this, result, n);
308 if (!good && token!=null)
309 throw new Parser.Failed(error(red("unexpected character")+" "+purple(token)+" encountered at "+green(getLocation())+"\n"),
311 if (token==null && finalResult==null)
312 throw new Parser.Failed(error(red("unexpected end of file\n")),
315 // this massively improves GC performance
320 public class Waiting {
324 boolean fromEmptyReduction;
326 public Waiting(Node parent, Forest pending, State state, boolean fromEmptyReduction, Reduction reduction) {
328 this.parent = parent;
329 this.pending = pending;
331 this.fromEmptyReduction = fromEmptyReduction;
332 this.reduction = reduction;
334 public void perform() {
335 //System.out.println("performing: " + reduction.position);
336 newNode(parent, pending, state, fromEmptyReduction, reduction);
340 // GSS Nodes //////////////////////////////////////////////////////////////////////////////
342 /** a node in the GSS */
343 public final class Node extends FastSet<Node> implements Invokable<Reduction, Node, Node> {
345 public boolean touched = false;
346 private Forest.Ref holder = null;
347 private boolean allqueued = false;
349 /** what state this node is in */
350 public final State state;
352 /** which Phase this Node belongs to (node that Node is also a non-static inner class of Phase) */
353 public Phase phase() { return Phase.this; }
355 public Forest.Ref holder() { return holder==null ? (holder = new Forest.Ref()) : holder; }
356 public Forest pending() { return Phase.this.closed ? holder().resolve() : holder; }
357 public FastSet<Node> parents() { return this; }
359 public void queueReductions() {
360 if (!reducing) return;
361 if (allqueued) return;
363 int where = parents().size();
364 state.invokeReductions(token, this, this, null);
367 public void queueReductions(Node n2) {
368 if (!allqueued) { queueReductions(); return; }
369 state.invokeReductions(token, this, this, n2);
372 public final void invoke(Reduction r, Node n, Node n2) {
374 if (r.numPop==0) r.reduce(this);
377 if (r.numPop==0) return;
378 if (n2==null) r.reduce(n);
379 else r.reduce(n, n2);
381 public void queueEmptyReductions() {
382 if (!reducing) return;
383 state.invokeReductions(token, this, null, null);
387 public boolean dead = false;
388 public boolean redo = false;
389 private Node(Node parent, Forest pending, State state, boolean fe) {
392 for(Position p : state) {
393 if (p.owner().needs!=null)
394 for(Sequence s : p.owner().needs) {
399 Phase start = parent==null ? null : parent.phase();
400 if (pending != null) this.holder().merge(pending);
401 if (parent != null) parents().add(parent, true);
402 if (Phase.this.hash.get(code(state, start)) != null) throw new Error("severe problem!");
403 Phase.this.hash.put(code(state, start), this);
404 Phase.this.numNodes++;
405 if (parent==null) holder().valid = true; // hack to make sure that the "base" node is always considered valid
412 private static boolean equal(Object a, Object b) {
413 if (a==null && b==null) return true;
414 if (a==null || b==null) return false;
418 /** this is something of a hack right now */
419 private static long code(State state, Phase start) {
420 return (((long)state.idx) << 32) | (start==null ? 0 : (start.pos+1));