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>, IntegerMappable {
28 public int toInt() { return pos+1; }
30 /** the token immediately after this phase */
31 public final Token token;
35 /** currently this is necessary only for the code() hack -- it doesn't actually correspond to the input */
36 private final int pos;
39 public Forest.Ref finalResult;
41 /** all nodes, keyed by the value returned by code() */
42 /*private*/ HashMap<Long,Phase.Node> hash; /* ALLOC */
44 /** the number of nodes in this phase */
50 private Phase next = null;
52 private Token.Location location;
53 public final Parser parser;
55 private Forest forest;
57 public Phase(Phase prev, Parser parser, Phase previous, Token token, Token.Location location, Forest forest) {
61 this.pos = previous==null ? 0 : previous.pos+1;
63 this.location = location;
73 hash = new HashMap<Long,Phase.Node>();
79 if (prev != null) prev.shift(this, forest);
82 public void complain(Node n, HashMap<String,HashSet<String>> errors, boolean force) {
83 if (n.touched) return;
85 for(Position p : n.state) {
87 if (((p.isFirst() || p.isLast()) && !force) || p.owner().name==null) {
88 for(Node n2 : n.parents())
89 complain(n2, errors, force | p.isFirst());
91 String seqname = p.owner().name;
92 HashSet<String> hs = errors.get(seqname);
93 if (hs==null) errors.put(seqname, hs = new HashSet<String>());
94 hs.add(p.element()+"");
95 //String s = " while parsing " + seqname + ": expected a " + p.element();
99 for(Position p2 = p.owner().firstp(); p2 != null && p2 != p && !p2.isLast(); p2 = p2.next()) s += (p2.element() + " ");
102 for(Position p2 = p; p2 != null && !p2.isLast(); p2 = p2.next()) s += (p2.element() + " ");
110 public String black(Object o) { return "\033[30m"+o+"\033[0m"; }
111 public String red(Object o) { return "\033[31m"+o+"\033[0m"; }
112 public String green(Object o) { return "\033[32m"+o+"\033[0m"; }
113 public String yellow(Object o) { return "\033[33m"+o+"\033[0m"; }
114 public String blue(Object o) { return "\033[34m"+o+"\033[0m"; }
115 public String purple(Object o) { return "\033[35m"+o+"\033[0m"; }
116 public String cyan(Object o) { return "\033[36m"+o+"\033[0m"; }
117 public String el(Object e) {
118 String s = e.toString();
119 if (s.length()==0 || s.charAt(0)!='\"' || s.charAt(s.length()-1)!='\"') return yellow(s);
121 s = s.substring(0, s.length()-1);
122 StringBuffer ret = new StringBuffer();
123 for(int i=0; i<s.length(); i++) {
124 if (s.charAt(i)=='\\' && i<s.length()-1) ret.append(s.charAt(++i));
127 return purple(ret.toString());
129 public String error(String message) {
130 String lookAhead = token==null ? "<EOF>" : token.toString();
131 StringBuffer ret = new StringBuffer();
134 HashMap<String,HashSet<String>> errors = new HashMap<String,HashSet<String>>();
135 for(Node n : hash.values()) {
136 //System.out.println(n.state);
137 complain(n, errors, false);
139 for(String s : errors.keySet()) {
140 ret.append(" while parsing " + yellow(s));
141 HashSet<String> hs = errors.get(s);
142 if (hs.size()==1) ret.append(" expected " + yellow(el(hs.iterator().next())) + "\n");
144 ret.append(" expected ");
145 boolean first = true;
146 for(String s2 : hs) {
147 if (!first) ret.append(" or ");
149 ret.append(yellow(el(s2)));
154 return ret.toString();
157 public boolean isDone() throws Parser.Failed {
158 if (token != null) return false;
159 if (token==null && finalResult==null)
160 throw new Parser.Failed(error(red("unexpected end of file\n")),
165 public Token.Location getLocation() { return location; }
167 /** add a new node (merging with existing nodes if possible)
168 * @param parent the parent of the new node
169 * @param result the SPPF result corresponding to the new node
170 * @param state the state that the new node is in
171 * @param fromEmptyReduction true iff this node is being created as a result of a reduction of length zero (see GRMLR paper)
172 * @param start the earliest part of the input contributing to this node (used to make merging decisions)
174 public boolean newNode(Node parent, Forest pending, State state, boolean fromEmptyReduction) {
175 Node p = hash.get(code(state, parent==null?null:parent.phase()));
176 if (p != null) return newNode2(p, parent, pending, state, fromEmptyReduction);
177 else return newNode3(parent, pending, state, fromEmptyReduction);
179 public void newNode(Node parent, Forest pending, State state, boolean fromEmptyReduction, Reduction reduction) {
180 int pos = parent==null?0:parent.phase()==null?0:parent.phase().pos;
181 Sequence owner = reduction==null ? null : reduction.position.owner();
182 if (reduction!=null) {
183 if (inhibited.contains(pos, owner)) return;
185 if (assumed.contains(pos, owner)) {
186 tail.add(new Waiting(parent, pending, state, fromEmptyReduction, reduction));
190 if (owner.needs != null)
191 for(Sequence s : owner.needs)
192 if (!performed.contains(pos, s)) {
193 waiting.add(s, new Waiting(parent, pending, state, fromEmptyReduction, reduction));
196 if ((owner.needed != null && owner.needed.size()>0) ||
197 (owner.hated != null && owner.hated.size()>0) ||
198 (owner.hates != null && owner.hates.size()>0))
199 performed.add(pos, owner);
202 newNode(parent, pending, state, fromEmptyReduction);
203 if (reduction!=null) inhibit(reduction, parent==null?0:parent.phase().pos);
204 if (reduction != null) {
208 for(Waiting w : waiting.getAll(owner)) {
209 if (w.parent==parent || (parent!=null&&w.parent!=null&&w.parent.phase()==parent.phase())) {
210 waiting.remove(owner, w);
219 private boolean newNode2(Node p, Node parent, Forest pending, State state, boolean fromEmptyReduction) {
220 p.holder.merge(pending);
221 if (p.parents().contains(parent)) return true;
222 p.parents().add(parent, true);
223 if (p!=parent && !fromEmptyReduction) p.queueReductions(parent);
226 private boolean newNode3(Node parent, Forest pending, State state, boolean fromEmptyReduction) {
228 if (token != null && state.canShift(token)) break;
229 if (state.isAccepting()) break;
230 if (token==null) break;
231 //if (!state.canReduce(token)) return false;
232 //if (count > 1) break;
233 //if (r.numPop == 0) break;
234 //r.reduce(pending, parent, null, Phase.this, null);
238 Node n = new Node(parent, pending, state, fromEmptyReduction); // ALLOC
239 n.queueEmptyReductions();
240 if (!fromEmptyReduction) n.queueReductions(parent);
244 public void uninhibit(int p, Sequence s) {
246 for(Sequence s2 : s.hated)
247 inhibited.remove(p, s2);
250 public void inhibit(Reduction r, int p) {
251 if (r.position.owner().hated == null) return;
252 // remember that dead states are still allowed to shift -- just not allowed to reduce
253 boolean reset = false;
254 for(Sequence seq : r.position.owner().hated) {
255 if (performed.contains(p,seq)) {
257 //System.out.println("\nresetting due to " + r.position.owner() + " killing " + seq);
259 inhibited.add(p, seq);
260 //assumed = inhibited;
261 //inhibited = new HashMapBag<Integer,Sequence>();
266 inhibited.add(p, seq);
270 /** perform all reduction operations */
271 public void reduce() {
274 if (reducing_list==null || reducing_list.length < hash.size())
275 reducing_list = new Phase.Node[hash.size() * 4];
276 Collection<Node> hv = hash.values();
277 hv.toArray(reducing_list);
279 for(int i=0; i<num; i++) {
280 Node n = reducing_list[i];
281 n.queueEmptyReductions();
282 // INVARIANT: we never "see" a node until its parent-set is complete, modulo merges
284 for(int i=0; i<num; i++) {
285 Node n = reducing_list[i];
286 reducing_list[i] = null;
289 //for(Waiting w : tail)
297 class Reset extends RuntimeException { }
299 public void invoke(State st, Forest result, Node n) {
300 boolean ok = next.newNode(n, result, st, false);
303 //if (good) System.out.println(st);
307 /** perform all shift operations, adding promoted nodes to <tt>next</tt> */
308 public void shift(Phase next, Forest result) throws Parser.Failed {
309 if (prev!=null) prev.hash = null;
314 for(Phase.Node n : hash.values()) {
315 if (token == null && n.state.isAccepting()) {
316 if (finalResult==null) finalResult = new Forest.Ref();
317 finalResult.merge(n.holder);
319 if (token == null) continue;
320 n.state.invokeShifts(token, this, result, n);
323 if (!good && token!=null)
324 throw new Parser.Failed(error(red("unexpected character")+" "+purple(token)+" encountered at "+green(getLocation())+"\n"),
326 if (token==null && finalResult==null)
327 throw new Parser.Failed(error(red("unexpected end of file\n")),
330 // this massively improves GC performance
335 public class Waiting {
339 boolean fromEmptyReduction;
341 public Waiting(Node parent, Forest pending, State state, boolean fromEmptyReduction, Reduction reduction) {
343 this.parent = parent;
344 this.pending = pending;
346 this.fromEmptyReduction = fromEmptyReduction;
347 this.reduction = reduction;
349 public void perform() {
350 //System.out.println("performing: " + reduction.position);
351 newNode(parent, pending, state, fromEmptyReduction, reduction);
355 // GSS Nodes //////////////////////////////////////////////////////////////////////////////
357 /** a node in the GSS */
358 public final class Node extends FastSet<Node> implements Invokable<Reduction, Node, Node> {
360 public boolean touched = false;
361 private Forest.Ref holder = null;
362 private boolean allqueued = false;
364 /** what state this node is in */
365 public final State state;
367 /** which Phase this Node belongs to (node that Node is also a non-static inner class of Phase) */
368 public Phase phase() { return Phase.this; }
370 public Forest.Ref holder() { return holder==null ? (holder = new Forest.Ref()) : holder; }
371 public Forest pending() { return Phase.this.closed ? holder().resolve() : holder; }
372 public FastSet<Node> parents() { return this; }
374 public void queueReductions() {
375 if (!reducing) return;
376 if (allqueued) return;
378 int where = parents().size();
379 state.invokeReductions(token, this, this, null);
382 public void queueReductions(Node n2) {
383 if (!allqueued) { queueReductions(); return; }
384 state.invokeReductions(token, this, this, n2);
387 public final void invoke(Reduction r, Node n, Node n2) {
389 if (r.numPop==0) r.reduce(this);
392 if (r.numPop==0) return;
393 if (n2==null) r.reduce(n);
394 else r.reduce(n, n2);
396 public void queueEmptyReductions() {
397 if (!reducing) return;
398 state.invokeReductions(token, this, null, null);
402 public boolean dead = false;
403 public boolean redo = false;
404 private Node(Node parent, Forest pending, State state, boolean fe) {
407 this.holder().merge(pending);
408 Phase start = parent==null ? null : parent.phase();
409 if (parent != null) parents().add(parent, true);
410 if (Phase.this.hash.get(code(state, start)) != null) throw new Error("severe problem!");
411 Phase.this.hash.put(code(state, start), this);
412 Phase.this.numNodes++;
419 private static boolean equal(Object a, Object b) {
420 if (a==null && b==null) return true;
421 if (a==null || b==null) return false;
425 /** this is something of a hack right now */
426 private static long code(State state, Phase start) {
427 return (((long)state.idx) << 32) | (start==null ? 0 : (start.pos+1));