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 */
14 static int shifts = 0;
15 static int reductions = 0;
21 private Phase.Node[] reducing_list = null;
23 // FIXME: right now, these are the performance bottleneck
24 HashMapBag<Sequence,Phase.Waiting> waiting = new HashMapBag<Sequence,Phase.Waiting>();
25 HashMapBag<Integer,Sequence> performed = new HashMapBag<Integer,Sequence>();
26 HashMapBag<Integer,Sequence> lastperformed = new HashMapBag<Integer,Sequence>();
27 HashMapBag<Integer,Sequence> expected = new HashMapBag<Integer,Sequence>();
30 Forest.Many finalResult;
32 /** corresponds to a positions <i>between tokens</i> the input stream; same as Tomita's U_i's */
33 class Phase<Tok> implements Invokable<State, Forest, Phase<Tok>.Node>, IntegerMappable, GraphViz.ToGraphViz, Iterable<Phase.Node> {
35 public Iterator<Phase.Node> iterator() { return hash.iterator(); }
36 public void invoke(State st, Forest result, Node n) {
38 good |= next.newNode(n, result, st, false);
41 /** the token immediately after this phase */
44 private final int pos;
47 private IntPairMap<Phase.Node> hash; /* ALLOC */
48 private boolean closed;
50 private Phase next = null;
52 private Input.Location location;
53 private Input.Location nextLocation;
54 public final Parser parser;
56 private Forest forest;
58 public Phase(Phase prev, Parser parser, Phase previous, Tok token, Input.Location location, Input.Location nextLocation, Forest forest) throws ParseFailed {
62 this.pos = previous==null ? 0 : previous.pos+1;
64 this.location = location;
65 this.nextLocation = nextLocation;
70 public void reset() throws ParseFailed {
73 lastperformed.clear();
74 lastperformed.addAll(performed);
76 hash = new IntPairMap<Phase.Node>();
82 if (prev != null) prev.shift(this, forest);
86 public boolean isDone() throws ParseFailed {
87 if (token != null) return false;
88 if (token==null && finalResult==null)
89 throw new ParseFailed(ParseFailed.error(ANSI.red("unexpected end of file\n"), token, hash.values()), getLocation());
93 public Input.Location getLocation() { return location; }
94 public Input.Location getNextLocation() { return nextLocation; }
96 /** add a new node (merging with existing nodes if possible)
97 * @param parent the parent of the new node
98 * @param result the SPPF result corresponding to the new node
99 * @param state the state that the new node is in
100 * @param fromEmptyReduction true iff this node is being created as a result of a reduction of length zero (see GRMLR paper)
101 * @param start the earliest part of the input contributing to this node (used to make merging decisions)
103 public boolean newNode(Node parent, Forest pending, State state, boolean fromEmptyReduction) {
104 Node p = hash.get(state, parent==null?null:parent.phase());
105 if (p != null) return newNode2(p, parent, pending, state, fromEmptyReduction);
106 else return newNode3(parent, pending, state, fromEmptyReduction);
108 public void newNode(Node parent, Forest pending, State state, boolean fromEmptyReduction, Position reduction) {
109 int pos = parent==null?0:parent.phase()==null?0:parent.phase().pos;
110 Sequence owner = reduction==null ? null : reduction.owner();
111 if (reduction!=null) {
112 if (owner.hates!=null) {
113 for (Sequence s : performed.getAll(pos))
114 if (owner.hates.contains(s))
116 for (Sequence s : lastperformed.getAll(pos))
117 if (owner.hates.contains(s)) {
118 //System.out.println("now expecting ["+pos+"] => " + s);
119 expected.add(pos, s);
123 if (owner.needs != null)
124 for(Sequence s : owner.needs)
125 if (!performed.contains(pos, s)) {
126 waiting.add(s, new Waiting(parent, pending, state, fromEmptyReduction, reduction));
129 if (!performed.contains(pos, owner)) {
130 performed.add(pos, owner);
131 if (owner.hated != null)
132 for(Sequence seq : owner.hated)
133 if (performed.contains(pos, seq)) {
134 performed.remove(pos, seq);
139 newNode(parent, pending, state, fromEmptyReduction);
140 if (reduction != null) {
144 for(Waiting w : waiting.getAll(owner)) {
145 if (w.parent==parent || (parent!=null&&w.parent!=null&&w.parent.phase()==parent.phase())) {
146 waiting.remove(owner, w);
156 private boolean newNode2(Node p, Node parent, Forest pending, State state, boolean fromEmptyReduction) {
157 if (p.merge(parent, pending)) return true;
158 p.parents().add(parent, true);
159 if (p!=parent && !fromEmptyReduction && reducing) p.performReductions(parent);
163 private boolean newNode3(Node parent, Forest pending, State state, boolean fromEmptyReduction) {
165 if (token != null && state.canShift(token)) break;
166 if (state.isAccepting()) break;
167 if (token==null) break;
168 if (!state.canReduce(token)) return false;
169 //if (count > 1) break;
170 //if (r.numPop == 0) break;
171 //r.reduce(pending, parent, null, Phase.this, null);
175 Node n = new Node(parent, pending, state); // ALLOC
177 n.performEmptyReductions();
178 if (!fromEmptyReduction) n.performReductions(parent);
183 /** perform all reduction operations */
184 public void reduce() throws ParseFailed {
187 if (reducing_list==null || reducing_list.length < hash.size())
188 reducing_list = new Phase.Node[hash.size() * 4];
189 hash.toArray(reducing_list);
190 int num = hash.size();
191 for(int i=0; i<num; i++) {
192 Node n = reducing_list[i];
193 n.performEmptyReductions();
194 // INVARIANT: we never "see" a node until its parent-set is complete, modulo merges
196 for(int i=0; i<num; i++) {
197 Node n = reducing_list[i];
198 reducing_list[i] = null;
199 n.performReductions();
206 for(int i : expected)
207 for(Sequence s : expected.getAll(i))
208 if (!performed.contains(i, s)) {
209 //System.out.println("resetting due to pos="+i+": " + s + " " + System.identityHashCode(s));
220 private boolean reset = false;
221 class Reset extends RuntimeException { }
223 /** perform all shift operations, adding promoted nodes to <tt>next</tt> */
224 public void shift(Phase next, Forest result) throws ParseFailed {
225 // this massively improves GC performance
226 if (prev!=null && parser.helpgc) {
233 for(Phase.Node n : hash.values()) {
234 if (token == null && n.state.isAccepting()) {
235 if (finalResult==null) finalResult = new Forest.Many();
236 for(Object f : n.results())
237 finalResult.merge((Forest)f);
239 if (token == null) continue;
240 n.state.invokeShifts(token, this, result, n);
243 if (!good && token!=null)
244 throw new ParseFailed(ParseFailed.error(ANSI.red("unexpected character ")+" \'"+
245 ANSI.purple(StringUtil.escapify(token+"", "\\\'\r\n"))+
246 "\' encountered at "+
247 ANSI.green(getLocation())+"\n", token, hash.values()),
249 if (token==null && finalResult==null)
250 throw new ParseFailed(ParseFailed.error(ANSI.red("unexpected end of file\n"), token, hash.values()),
259 boolean fromEmptyReduction;
261 public Waiting(Node parent, Forest pending, State state, boolean fromEmptyReduction, Position reduction) {
263 this.parent = parent;
264 this.pending = pending;
266 this.fromEmptyReduction = fromEmptyReduction;
267 this.reduction = reduction;
269 public void perform() {
270 //System.out.println("performing: " + reduction.position);
271 newNode(parent, pending, state, fromEmptyReduction, reduction);
275 // Node /////////////////////////////////////////////////////////////////////////////////
277 /** a node in the GSS */
278 final class Node implements Invokable<Position, Node, Node>, IntegerMappable, GraphViz.ToGraphViz {
279 public FastSet<Node> set = new FastSet<Node>();
282 private boolean allqueued = false;
284 /** what state this node is in */
285 public final Parser.Table<Tok>.State<Tok> state;
287 /** which Phase this Node belongs to (node that Node is also a non-static inner class of Phase) */
288 public Phase phase() { return Phase.this; }
290 private HashSet<Forest.Many> resultMap = new HashSet<Forest.Many>();
291 public Iterable<Forest.Many> results() { return resultMap; }
292 public FastSet<Node> parents() { return set; }
293 public boolean merge(Node parent, Forest result) {
294 // FIXME: inefficient!
295 for(Forest.Many f : results()) {
296 if (f.parents.contains(parent) /* UGLY: */ && f.parents.size()==1) {
301 Forest.Many f = new Forest.Many();
302 f.parents.add(parent);
305 set.add(parent, true);
309 public void performReductions() {
310 if (allqueued) return;
312 state.invokeReductions(token, this, this, null);
315 public void performReductions(Node n2) {
316 if (!allqueued) performReductions();
317 else state.invokeReductions(token, this, this, n2);
320 public void performEmptyReductions() { state.invokeReductions(token, this, null, null); }
321 public final void invoke(Position r, Node n, Node n2) {
323 if (n==null || n2==null || r.pos==0) {
325 if (n==null) n = this;
329 Forest[] holder = new Forest[r.pos];
330 if (r.pos==0) n.finish(r, r.zero(n.phase().getLocation().createRegion(n.phase().getLocation())), n.phase());
331 else n.reduce(r, r.pos-1, n.phase(), null);
333 if (r.pos<=0) throw new Error("called wrong form of reduce()");
335 n.reduce(r, pos, n.phase(), n2);
339 public void reduce(Position r, int pos, Phase target, Node only) {
340 Forest[] holder = r.holder;
341 Forest old = holder[pos];
343 HashSet<Forest> rr = new HashSet<Forest>();
344 for(Forest result : results()) rr.add(result);
345 for(Forest result : rr)
346 for(Node child : ((Forest.Many<?>)result).parents) {
347 if (only != null && child!=only) continue;
348 holder[pos] = result;
349 if (pos==0) child.finish(r, r.rewrite(child.phase().getNextLocation().createRegion(target.getLocation())), target);
350 else child.reduce(r, pos-1, target, null);
356 public void finish(Position r, Forest result, Phase<Tok> target) {
357 Parser.Table<Tok>.State<Tok> state0 = state.gotoSetNonTerminals.get(r.owner());
358 if (result==null) throw new Error();
360 target.newNode(this, result, state0, r.pos<=0, r);
363 private Node(Node parent, Forest pending, State state) {
365 this.merge(parent, pending);
366 Phase start = parent==null ? null : parent.phase();
367 if (parent != null) parents().add(parent, true);
368 if (Phase.this.hash.get(state, start) != null) throw new Error("severe problem!");
369 Phase.this.hash.put(state, start, this);
371 public int toInt() { return idx; }
372 private final int idx = node_idx++;
374 // GraphViz //////////////////////////////////////////////////////////////////////////////
376 public GraphViz.Node toGraphViz(GraphViz gv) {
377 if (gv.hasNode(this)) return gv.createNode(this);
378 GraphViz.Node n = gv.createNode(this);
379 n.label = ""+state.toStringx();
380 n.shape = "rectangle";
382 for(Forest result : results()) n.edge(result, "");
383 for(Node parent : parents()) n.edge(parent, "");
384 ((GraphViz.Group)phase().toGraphViz(gv)).add(n);
387 public boolean isTransparent() { return false; }
388 public boolean isHidden() { return false; }
391 private int node_idx = 0;
393 public int toInt() { return pos+1; }
394 public int size() { return hash==null ? 0 : hash.size(); }
396 // GraphViz //////////////////////////////////////////////////////////////////////////////
398 public GraphViz.Node toGraphViz(GraphViz gv) {
399 if (gv.hasNode(this)) return gv.createNode(this);
400 GraphViz.Group g = gv.createGroup(this);
401 g.label = "Phase " + pos;
406 public boolean isTransparent() { return false; }
407 public boolean isHidden() { return false; }