public Forest<R> parse(Token.Stream<T> input) throws IOException, Failed {
GSS gss = new GSS();
Token.Location loc = input.getLocation();
- GSS.Phase current = gss.new Phase(null, input.next(), loc);
- current.newNode(null, null, pt.start, true, null);
+ GSS.Phase current = gss.new Phase(null, input.next(1), loc);
+ current.newNode(null, null, pt.start, true);
+ int count = 1;
for(;;) {
loc = input.getLocation();
- GSS.Phase next = gss.new Phase(current, input.next(), loc);
+ GSS.Phase next = gss.new Phase(current, input.next(count), loc);
current.reduce();
Forest forest = current.token==null ? null : shiftedToken((T)current.token, loc);
current.shift(next, forest);
- if (current.isDone()) return (Forest<R>)current.finalResult;
+ count = next.hash.size();
current.checkFailure();
+ if (current.isDone()) return (Forest<R>)current.finalResult;
current = next;
}
}
if (start0.contains(p.owner()) && p.next()==null)
state.accept = true;
- // FIXME: how does right-nullability interact with follow restrictions?
- // all right-nullable rules get a reduction [Johnstone 2000]
if (p.isRightNullable(cache)) {
Walk.Follow wf = new Walk.Follow(top.empty(), p.owner(), all_elements, cache);
Reduction red = new Reduction(p);
- state.reductions.put(wf.walk(p.owner()), red);
+
+ Topology follow = wf.walk(p.owner());
+ if (p.owner() instanceof Sequence.RewritingSequence &&
+ (((Sequence.RewritingSequence)p.owner()).tag+"").equals("emailaddr")) {
+ System.out.println("follow before: " + new edu.berkeley.sbp.misc.CharToken.CharRange(follow));
+ }
+ for(Position p2 = p; p2 != null && p2.element() != null; p2 = p2.next())
+ follow = follow.intersect(new Walk.Follow(top.empty(), p2.element(), all_elements, cache).walk(p2.element()));
+ if (p.owner() instanceof Sequence.RewritingSequence &&
+ (((Sequence.RewritingSequence)p.owner()).tag+"").equals("emailaddr")) {
+ System.out.println("follow after: " + new edu.berkeley.sbp.misc.CharToken.CharRange(follow));
+ }
+ state.reductions.put(follow, red);
if (wf.includesEof()) state.eofReductions.add(red);
}
if (p.element() != null && p.element() instanceof Atom)
state.shifts.addAll(state.gotoSetTerminals.subset(((Atom)p.element())));
}
+ for(State state : all_states.values()) {
+ state.oreductions = state.reductions.optimize();
+ state.oshifts = state.shifts.optimize();
+ }
}
/** a single state in the LR table and the transitions possible from it */
private TopologicalBag<Token,State> shifts = new TopologicalBag<Token,State>();
private boolean accept = false;
+ private VisitableMap<Token,State> oshifts = null;
+ private VisitableMap<Token,Reduction> oreductions = null;
+
// Interface Methods //////////////////////////////////////////////////////////////////////////////
- public boolean canShift(Token t) { return shifts.contains(t); }
- public Iterable<State> getShifts(Token t) { return shifts.get(t); }
public boolean isAccepting() { return accept; }
- public Iterable<Reduction> getReductions(Token t) { return t==null ? eofReductions : reductions.get(t); }
- public Iterable<Reduction> getEofReductions() { return eofReductions; }
+
+ public boolean canShift(Token t) { return oshifts.contains(t); }
+ public boolean canReduce(Token t) { return t==null ? eofReductions.size()>0 : oreductions.contains(t); }
+
public Iterator<Position> iterator() { return hs.iterator(); }
+ public <B,C> void invokeShifts(Token t, Invokable<State,B,C> irbc, B b, C c) {
+ oshifts.invoke(t, irbc, b, c);
+ }
+ public <B,C> void invokeReductions(Token t, Invokable<Reduction,B,C> irbc, B b, C c) {
+ if (t==null) for(Reduction r : eofReductions) irbc.invoke(r, b, c);
+ else oreductions.invoke(t, irbc, b, c);
+ }
+
// Constructor //////////////////////////////////////////////////////////////////////////////
/**
}
public String toString() { return "[reduce " + position + "]"; }
- public Forest reduce(GSS.Phase.Node parent, GSS.Phase.Node onlychild, Forest rex) {
- Forest ret = reduce(parent, numPop-1, rex, onlychild, parent.phase());
- return ret;
- }
-
private Forest zero = null;
public Forest zero() {
if (zero != null) return zero;
return zero = position.rewrite(null);
}
+ public void reduce(GSS.Phase.Node parent) {
+ if (numPop==0) finish(parent, zero(), parent.phase());
+ else reduce(parent, numPop-1, parent.phase());
+ }
+
+ public void reduce(GSS.Phase.Node parent, GSS.Phase.Node onlychild) {
+ if (numPop<=0) throw new Error("called wrong form of reduce()");
+ int pos = numPop-1;
+ Forest old = holder[pos];
+ holder[pos] = parent.pending();
+ if (pos==0) {
+ System.arraycopy(holder, 0, position.holder, 0, holder.length);
+ finish(onlychild, position.rewrite(parent.phase().getLocation()), parent.phase());
+ } else {
+ reduce(onlychild, pos-1, parent.phase());
+ }
+ holder[pos] = old;
+ }
+
// FIXME: this could be more elegant and/or cleaner and/or somewhere else
- private Forest reduce(GSS.Phase.Node parent, int pos, Forest rex, GSS.Phase.Node onlychild, GSS.Phase target) {
- if (pos>=0) holder[pos] = parent.pending();
+ private void reduce(GSS.Phase.Node parent, int pos, GSS.Phase target) {
+ Forest old = holder[pos];
+ holder[pos] = parent.pending();
if (pos==0) {
- if (rex==null) {
- System.arraycopy(holder, 0, position.holder, 0, holder.length);
- rex = position.rewrite(target.getLocation());
- }
- if (onlychild != null)
- reduce(onlychild, pos-1, rex, null, target);
- else
- for(GSS.Phase.Node child : parent.parents())
- reduce(child, pos-1, rex, null, target);
- } else if (pos>0) {
- if (onlychild != null)
- reduce(onlychild, pos-1, rex, null, target);
- else
- for(GSS.Phase.Node child : parent.parents())
- reduce(child, pos-1, rex, null, target);
+ System.arraycopy(holder, 0, position.holder, 0, holder.length);
+ for(int i=0; i<position.pos; i++) if (position.holder[i]==null) throw new Error("realbad");
+ Forest rex = position.rewrite(target.getLocation());
+ for(GSS.Phase.Node child : parent.parents()) finish(child, rex, target);
} else {
- State state = parent.state.gotoSetNonTerminals.get(position.owner());
- if (state!=null)
- target.newNode(parent, rex, state, numPop<=0, parent.phase());
+ for(GSS.Phase.Node child : parent.parents()) reduce(child, pos-1, target);
}
- return rex;
+ holder[pos] = old;
+ }
+ private void finish(GSS.Phase.Node parent, Forest result, GSS.Phase target) {
+ State state = parent.state.gotoSetNonTerminals.get(position.owner());
+ if (state!=null)
+ target.newNode(parent, result, state, numPop<=0);
}
}
}
projects / sbp.git / blobdiff