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;
17 private Phase.Node[] reducing_list = null;
18 public int resets = 0;
21 HashMapBag<Sequence,Phase.Waiting> waiting = new HashMapBag<Sequence,Phase.Waiting>();
22 HashMapBag<Integer,Sequence> performed = new HashMapBag<Integer,Sequence>();
23 HashMapBag<Integer,Sequence> lastperformed = new HashMapBag<Integer,Sequence>();
24 HashMapBag<Integer,Sequence> expected = new HashMapBag<Integer,Sequence>();
27 public Forest.Ref finalResult;
29 /** corresponds to a positions <i>between tokens</i> the input stream; same as Tomita's U_i's */
30 class Phase<Tok> implements Invokable<State, Forest, Phase<Tok>.Node>, IntegerMappable, GraphViz.ToGraphViz, Iterable<Phase.Node> {
32 public Iterator<Phase.Node> iterator() { return hash.iterator(); }
33 public void invoke(State st, Forest result, Node n) {
34 good |= next.newNode(n, result, st, false);
37 /** the token immediately after this phase */
40 private final int pos;
43 private IntPairMap<Phase.Node> hash; /* ALLOC */
44 private boolean closed;
46 private Phase next = null;
48 private Input.Location location;
49 public final Parser parser;
51 private Forest forest;
53 public Phase(Phase prev, Parser parser, Phase previous, Tok token, Input.Location location, Forest forest) throws ParseFailed {
57 this.pos = previous==null ? 0 : previous.pos+1;
59 this.location = location;
64 public void reset() throws ParseFailed {
67 lastperformed.clear();
68 lastperformed.addAll(performed);
70 hash = new IntPairMap<Phase.Node>();
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);
150 private boolean newNode2(Node p, Node parent, Forest pending, State state, boolean fromEmptyReduction) {
151 //if (p.parents().contains(parent)) return true;
152 if (p.merge(parent, pending)) return true;
153 p.parents().add(parent, true);
154 if (p!=parent && !fromEmptyReduction && reducing) p.performReductions(parent);
158 private boolean newNode3(Node parent, Forest pending, State state, boolean fromEmptyReduction) {
160 if (token != null && state.canShift(token)) break;
161 if (state.isAccepting()) break;
162 if (token==null) break;
163 if (!state.canReduce(token)) return false;
164 //if (count > 1) break;
165 //if (r.numPop == 0) break;
166 //r.reduce(pending, parent, null, Phase.this, null);
170 Node n = new Node(parent, pending, state); // ALLOC
172 n.performEmptyReductions();
173 if (!fromEmptyReduction) n.performReductions(parent);
178 /** perform all reduction operations */
179 public void reduce() throws ParseFailed {
182 if (reducing_list==null || reducing_list.length < hash.size())
183 reducing_list = new Phase.Node[hash.size() * 4];
184 hash.toArray(reducing_list);
185 int num = hash.size();
186 for(int i=0; i<num; i++) {
187 Node n = reducing_list[i];
188 n.performEmptyReductions();
189 // INVARIANT: we never "see" a node until its parent-set is complete, modulo merges
191 for(int i=0; i<num; i++) {
192 Node n = reducing_list[i];
193 reducing_list[i] = null;
194 n.performReductions();
201 for(int i : expected)
202 for(Sequence s : expected.getAll(i))
203 if (!performed.contains(i, s)) {
204 //System.out.println("resetting due to pos="+i+": " + s + " " + System.identityHashCode(s));
215 private boolean reset = false;
216 class Reset extends RuntimeException { }
218 /** perform all shift operations, adding promoted nodes to <tt>next</tt> */
219 public void shift(Phase next, Forest result) throws ParseFailed {
220 // this massively improves GC performance
221 if (prev!=null && parser.helpgc) {
228 for(Phase.Node n : hash.values()) {
229 if (token == null && n.state.isAccepting()) {
230 if (finalResult==null) finalResult = new Forest.Ref();
231 for(Object f : n.results())
232 finalResult.merge((Forest)f);
234 if (token == null) continue;
235 n.state.invokeShifts(token, this, result, n);
238 if (!good && token!=null)
239 throw new ParseFailed(ParseFailed.error(ANSI.red("unexpected character ")+" \'"+
240 ANSI.purple(StringUtil.escapify(token+"", "\\\'\r\n"))+
241 "\' encountered at "+
242 ANSI.green(getLocation())+"\n", token, hash.values()),
244 if (token==null && finalResult==null)
245 throw new ParseFailed(ParseFailed.error(ANSI.red("unexpected end of file\n"), token, hash.values()),
254 boolean fromEmptyReduction;
256 public Waiting(Node parent, Forest pending, State state, boolean fromEmptyReduction, Position reduction) {
258 this.parent = parent;
259 this.pending = pending;
261 this.fromEmptyReduction = fromEmptyReduction;
262 this.reduction = reduction;
264 public void perform() {
265 //System.out.println("performing: " + reduction.position);
266 newNode(parent, pending, state, fromEmptyReduction, reduction);
270 // Node /////////////////////////////////////////////////////////////////////////////////
272 /** a node in the GSS */
273 final class Node implements Invokable<Position, Node, Node>, IntegerMappable, GraphViz.ToGraphViz {
274 public FastSet<Node> set = new FastSet<Node>();
276 public GraphViz.Node toGraphViz(GraphViz gv) {
277 if (gv.hasNode(this)) return gv.createNode(this);
278 GraphViz.Node n = gv.createNode(this);
279 n.label = ""+state.toStringx();
280 n.shape = "rectangle";
282 //GraphViz.Node f = pending().toGraphViz(gv);
284 for(Forest result : results()) n.edge(result, "");
285 for(Node parent : parents()) n.edge(parent, "");
286 ((GraphViz.Group)phase().toGraphViz(gv)).add(n);
289 public boolean isTransparent() { return false; }
290 public boolean isHidden() { return false; }
292 private boolean allqueued = false;
294 /** what state this node is in */
295 public final Parser.Table<Tok>.State<Tok> state;
297 /** which Phase this Node belongs to (node that Node is also a non-static inner class of Phase) */
298 public Phase phase() { return Phase.this; }
300 private HashSet<Forest.Ref> resultMap = new HashSet<Forest.Ref>();
301 public Iterable<Forest.Ref> results() { return resultMap; }
302 public FastSet<Node> parents() { return set; }
303 public boolean merge(Node parent, Forest result) {
304 for(Forest.Ref f : results()) {
305 if (f.parents.contains(parent) /* UGLY: */ && f.parents.size()==1) {
310 Forest.Ref f = new Forest.Ref();
311 f.parents.add(parent);
314 set.add(parent, true);
318 public void performReductions() {
319 if (allqueued) return;
321 state.invokeReductions(token, this, this, null);
324 public void performReductions(Node n2) {
325 if (!allqueued) performReductions();
326 else state.invokeReductions(token, this, this, n2);
329 public void performEmptyReductions() { state.invokeReductions(token, this, null, null); }
330 public final void invoke(Position r, Node n, Node n2) {
331 if (n==null || n2==null || r.pos==0) {
333 if (n==null) n = this;
337 Forest[] holder = new Forest[r.pos];
338 if (r.pos==0) n.finish(r, r.zero(), n.phase(), holder);
339 else n.reduce(r, r.pos-1, n.phase(), holder, null);
341 Forest[] holder = new Forest[r.pos];
342 if (r.pos<=0) throw new Error("called wrong form of reduce()");
344 n.reduce(r, pos, n.phase(), holder, n2);
348 public void reduce(Position r, int pos, Phase target, Forest[] holder, Node only) {
349 Forest old = holder[pos];
351 for(Forest result : results())
352 for(Node child : ((Forest.Ref<?>)result).parents) {
353 if (only != null && child!=only) continue;
354 holder[pos] = result;
356 System.arraycopy(holder, 0, r.holder, 0, holder.length);
357 for(int i=0; i<r.pos; i++) if (r.holder[i]==null) throw new Error("realbad");
358 child.finish(r, r.rewrite(phase().getLocation()), target, holder);
360 child.reduce(r, pos-1, target, holder, null);
367 public void finish(Position r, Forest result, Phase<Tok> target, Forest[] holder) {
368 Parser.Table<Tok>.State<Tok> state0 = state.gotoSetNonTerminals.get(r.owner());
369 if (result==null) throw new Error();
371 target.newNode(this, result, state0, r.pos<=0, r);
374 private Node(Node parent, Forest pending, State state) {
376 this.merge(parent, pending);
377 Phase start = parent==null ? null : parent.phase();
378 if (parent != null) parents().add(parent, true);
379 if (Phase.this.hash.get(state, start) != null) throw new Error("severe problem!");
380 Phase.this.hash.put(state, start, this);
382 public int toInt() { return idx; }
383 private final int idx = node_idx++;
385 private int node_idx = 0;
387 public int toInt() { return pos+1; }
388 public int size() { return hash==null ? 0 : hash.size(); }
390 // GraphViz //////////////////////////////////////////////////////////////////////////////
392 public GraphViz.Node toGraphViz(GraphViz gv) {
393 if (gv.hasNode(this)) return gv.createNode(this);
394 GraphViz.Group g = gv.createGroup(this);
395 g.label = "Phase " + pos;
400 public boolean isTransparent() { return false; }
401 public boolean isHidden() { return false; }