+// Copyright 2006 all rights reserved; see LICENSE file for BSD-style license
+
package edu.berkeley.sbp;
import edu.berkeley.sbp.*;
import edu.berkeley.sbp.util.*;
/** implements Tomita's Graph Structured Stack */
class GSS {
- public GSS() { }
-
- private Phase.Node[] reducing_list = null;
- public int resets = 0;
- public int waits = 0;
+ Input input;
+ public GSS(Input input) { this.input = input; }
+ public Input getInput() { return input; }
- HashMapBag<Integer,Sequence> inhibited = new HashMapBag<Integer,Sequence>();
- HashMapBag<Integer,Sequence> expectedInhibit = new HashMapBag<Integer,Sequence>();
- HashMapBag<Sequence,Phase.Waiting> waiting = new HashMapBag<Sequence,Phase.Waiting>();
+ // FIXME: right now, these are the performance bottleneck
HashMapBag<Integer,Sequence> performed = new HashMapBag<Integer,Sequence>();
-
+
/** FIXME */
- public Forest.Ref finalResult;
+ Forest.Many finalResult;
/** corresponds to a positions <i>between tokens</i> the input stream; same as Tomita's U_i's */
- class Phase<Tok> implements Invokable<State, Forest, Phase<Tok>.Node>, IntegerMappable {
+ class Phase<Tok> implements Invokable<State, Result, Object>, IntegerMappable, GraphViz.ToGraphViz, Iterable<Node> {
- public void invoke(State st, Forest result, Node n) {
- good |= next.newNode(n, result, st, false);
+ public PriorityQueue<Reduction> reductionQueue = new PriorityQueue<Reduction>();
+
+ public void invoke(State st, Result result, Object o) {
+ //shifts++;
+ good |= next.newNode(result, st, false);
}
/** the token immediately after this phase */
final Tok token;
+ final int pos;
- private final int pos;
-
- boolean reducing;
- private IntPairMap<Phase.Node> hash; /* ALLOC */
- private IntPairMap<Forest> singularReductions; /* ALLOC */
- private boolean closed;
+ public IntPairMap<Node> hash; /* ALLOC */
private boolean good;
private Phase next = null;
private Phase prev;
private Input.Location location;
- public final Parser parser;
-
+ private Input.Location nextLocation;
+ private Input.Location prevLocation;
+
private Forest forest;
- public Phase(Phase prev, Parser parser, Phase previous, Tok token, Input.Location location, Forest forest) throws ParseFailed {
+ public Phase(Phase prev, Phase previous, Tok token, Input.Location location,
+ Input.Location nextLocation, Forest forest) throws ParseFailed {
+ this.prevLocation = prev==null ? location : prev.getLocation();
this.prev = prev;
this.forest = forest;
- this.parser = parser;
this.pos = previous==null ? 0 : previous.pos+1;
this.token = token;
this.location = location;
- inhibited.clear();
- reset();
- }
-
- public void reset() throws ParseFailed {
- waiting.clear();
+ this.nextLocation = nextLocation;
performed.clear();
- hash = new IntPairMap<Phase.Node>();
- singularReductions = new IntPairMap<Forest>();
- expectedInhibit.clear();
- expectedInhibit.addAll(inhibited);
+ hash = new IntPairMap<Node>();
good = false;
- closed = false;
- reducing = false;
finalResult = null;
if (prev != null) prev.shift(this, forest);
}
-
+ public boolean isFrontier() { return next==null; }
public boolean isDone() throws ParseFailed {
if (token != null) return false;
if (token==null && finalResult==null)
- throw new ParseFailed(ParseFailed.error(ANSI.red("unexpected end of file\n"), token, hash.values()), getLocation());
+ ParseFailed.error("unexpected end of file", this);
return true;
}
+ public Input.Location getPrevLocation() { return prevLocation; }
public Input.Location getLocation() { return location; }
+ public Input.Region getRegion() { return getPrevLocation().createRegion(getLocation()); }
+ public Input.Location getNextLocation() { return nextLocation; }
+
+ /** perform all shift operations, adding promoted nodes to <tt>next</tt> */
+ public void shift(Phase next, Forest result) throws ParseFailed {
+ // this massively improves GC performance
+ if (prev!=null) prev.hash = null;
+ this.next = next;
+ for(Node n : hash.values()) {
+ if (token == null && n.state().isAccepting()) {
+ if (finalResult==null) finalResult = new Forest.Many();
+ for(Result r : n)
+ finalResult.merge(r.getForest());
+ }
+ if (token == null) continue;
+ n.state().invokeShifts(token, this, new Result(result, n, null), null);
+ }
+ for(Node n : hash.values()) n.check();
+ if (!good && token!=null) ParseFailed.error("unexpected character", this);
+ if (token==null && finalResult==null) ParseFailed.error("unexpected end of file", this);
+ }
+
+ /** perform all reduction operations */
+ public void reduce() throws ParseFailed {
+ while(!reductionQueue.isEmpty())
+ reductionQueue.poll().perform();
+ }
+
+ public void newNodeFromReduction(Result result, State state, boolean fromEmptyReduction, Position reduction) {
+ int pos = result.phase().pos;
+ Sequence owner = reduction.owner();
+ for(Sequence s : owner.hates)
+ if (performed.contains(pos, s))
+ return;
+ for(Sequence s : owner.needs)
+ if (!performed.contains(pos, s))
+ return;
+ if (owner.needed_or_hated && !performed.contains(pos, owner))
+ performed.add(pos, owner);
+ if (state!=null)
+ newNode(result, state, fromEmptyReduction);
+ }
/** add a new node (merging with existing nodes if possible)
* @param parent the parent of the new node
* @param fromEmptyReduction true iff this node is being created as a result of a reduction of length zero (see GRMLR paper)
* @param start the earliest part of the input contributing to this node (used to make merging decisions)
*/
- public boolean newNode(Node parent, Forest pending, State state, boolean fromEmptyReduction) {
- Node p = hash.get(state, parent==null?null:parent.phase());
- if (p != null) return newNode2(p, parent, pending, state, fromEmptyReduction);
- else return newNode3(parent, pending, state, fromEmptyReduction);
- }
- public void newNode(Node parent, Forest pending, State state, boolean fromEmptyReduction, Position reduction) {
- int pos = parent==null?0:parent.phase()==null?0:parent.phase().pos;
- Sequence owner = reduction==null ? null : reduction.owner();
- if (reduction!=null) {
- if (inhibited.contains(pos, owner)) return;
- if (owner.needs != null)
- for(Sequence s : owner.needs)
- if (!performed.contains(pos, s)) {
- waiting.add(s, new Waiting(parent, pending, state, fromEmptyReduction, reduction));
- return;
- }
- if ((owner.needed != null && owner.needed.size()>0) ||
- (owner.hated != null && owner.hated.size()>0) ||
- (owner.hates != null && owner.hates.size()>0))
- performed.add(pos, owner);
- }
- if (!owner.lame)
- newNode(parent, pending, state, fromEmptyReduction);
- if (reduction!=null) inhibit(reduction, parent==null?0:parent.phase().pos);
- if (reduction != null) {
- boolean redo = true;
- while(redo) {
- redo = false;
- for(Waiting w : waiting.getAll(owner)) {
- if (w.parent==parent || (parent!=null&&w.parent!=null&&w.parent.phase()==parent.phase())) {
- waiting.remove(owner, w);
- w.perform();
- redo = true;
- break;
- }
- }
- }
- }
- }
- private boolean newNode2(Node p, Node parent, Forest pending, State state, boolean fromEmptyReduction) {
- p.holder.merge(pending);
- if (p.parents().contains(parent)) return true;
- p.parents().add(parent, true);
- if (p!=parent && !fromEmptyReduction && reducing) p.performReductions(parent);
- return true;
- }
- private boolean newNode3(Node parent, Forest pending, State state, boolean fromEmptyReduction) {
+ public boolean newNode(Result result, State state, boolean fromEmptyReduction) {
+ Node p = hash.get(state, result.phase());
+ if (p != null) { p.merge(result); return true; }
do {
if (token != null && state.canShift(token)) break;
if (state.isAccepting()) break;
if (token==null) break;
if (!state.canReduce(token)) return false;
- //if (count > 1) break;
- //if (r.numPop == 0) break;
- //r.reduce(pending, parent, null, Phase.this, null);
- //return;
} while(false);
-
- Node n = new Node(parent, pending, state); // ALLOC
- if (reducing) {
- n.performEmptyReductions();
- if (!fromEmptyReduction) n.performReductions(parent);
- }
+ new Node(Phase.this, result, state, fromEmptyReduction); // ALLOC
return true;
}
- public void uninhibit(int p, Sequence s) {
- if (s.hated!=null)
- for(Sequence s2 : s.hated)
- inhibited.remove(p, s2);
- }
-
- public void inhibit(Position r, int p) {
- if (r.owner().hated == null) return;
- // remember that dead states are still allowed to shift -- just not allowed to reduce
- boolean reset = false;
- for(Sequence seq : r.owner().hated) {
- if (performed.contains(p,seq)) {
- uninhibit(p, seq);
- //System.out.println("\nresetting due to " + r.owner() + " killing " + seq);
- //inhibited.clear();
- inhibited.add(p, seq);
- //inhibited = new HashMapBag<Integer,Sequence>();
- reset = true;
- resets++;
- throw new Reset();
- }
- inhibited.add(p, seq);
- expectedInhibit.remove(p, seq);
- }
- }
-
- /** perform all reduction operations */
- public void reduce() throws ParseFailed{
- try {
- reducing = true;
- if (reducing_list==null || reducing_list.length < hash.size())
- reducing_list = new Phase.Node[hash.size() * 4];
- hash.toArray(reducing_list);
- int num = hash.size();
- for(int i=0; i<num; i++) {
- Node n = reducing_list[i];
- n.performEmptyReductions();
- // INVARIANT: we never "see" a node until its parent-set is complete, modulo merges
- }
- for(int i=0; i<num; i++) {
- Node n = reducing_list[i];
- reducing_list[i] = null;
- n.performReductions();
- }
- if (expectedInhibit.size() > 0) {
- inhibited.removeAll(expectedInhibit);
- System.out.println("\n!!!!\n");
- throw new Reset();
- }
- } catch (Reset r) {
- reset();
- reduce();
- }
- }
-
- class Reset extends RuntimeException { }
-
- /** perform all shift operations, adding promoted nodes to <tt>next</tt> */
- public void shift(Phase next, Forest result) throws ParseFailed {
- // this massively improves GC performance
- if (prev!=null) {
- prev.hash = null;
- prev.singularReductions = null;
- }
- this.next = next;
- closed = true;
- Forest res = null;
- boolean ok = false;
- for(Phase.Node n : hash.values()) {
- if (token == null && n.state.isAccepting()) {
- if (finalResult==null) finalResult = new Forest.Ref();
- finalResult.merge(n.holder);
- }
- if (token == null) continue;
- n.state.invokeShifts(token, this, result, n);
- }
-
- if (!good && token!=null)
- throw new ParseFailed(ParseFailed.error(ANSI.red("unexpected character ")+" \'"+
- ANSI.purple(StringUtil.escapify(token+"", "\\\'\r\n"))+
- "\' encountered at "+
- ANSI.green(getLocation())+"\n", token, hash.values()),
- getLocation());
- if (token==null && finalResult==null)
- throw new ParseFailed(ParseFailed.error(ANSI.red("unexpected end of file\n"), token, hash.values()),
- getLocation());
- }
-
-
- public class Waiting {
- Node parent;
- Forest pending;
- State state;
- boolean fromEmptyReduction;
- Position reduction;
- public Waiting(Node parent, Forest pending, State state, boolean fromEmptyReduction, Position reduction) {
- waits++;
- this.parent = parent;
- this.pending = pending;
- this.state = state;
- this.fromEmptyReduction = fromEmptyReduction;
- this.reduction = reduction;
- }
- public void perform() {
- //System.out.println("performing: " + reduction.position);
- newNode(parent, pending, state, fromEmptyReduction, reduction);
- }
- }
-
- // Node /////////////////////////////////////////////////////////////////////////////////
-
- /** a node in the GSS */
- public final class Node extends FastSet<Node> implements Invokable<Position, Node, Node>, IntegerMappable {
-
- private Forest.Ref holder = null;
- private boolean allqueued = false;
-
- /** what state this node is in */
- public final Parser.Table<Tok>.State<Tok> state;
-
- /** which Phase this Node belongs to (node that Node is also a non-static inner class of Phase) */
- public Phase phase() { return Phase.this; }
- public Forest.Ref holder() { return holder==null ? (holder = new Forest.Ref()) : holder; }
- public Forest pending() { return Phase.this.closed ? holder().resolve() : holder; }
- public FastSet<Node> parents() { return this; }
-
- public void performReductions() {
- if (allqueued) return;
- allqueued = true;
- state.invokeReductions(token, this, this, null);
- }
-
- public void performReductions(Node n2) {
- if (!allqueued) performReductions();
- else state.invokeReductions(token, this, this, n2);
- }
-
- public void performEmptyReductions() { state.invokeReductions(token, this, null, null); }
- public final void invoke(Position r, Node n, Node n2) {
- if (n==null || n2==null || r.pos==0) {
- if (r.pos==0) {
- if (n==null) n = this;
- else return;
- }
- if (n==null) return;
- Forest[] holder = new Forest[r.pos];
- if (r.pos==0) n.finish(r, r.zero(), n.phase(), holder);
- else n.reduce(r, r.pos-1, n.phase(), holder);
- } else {
- Forest[] holder = new Forest[r.pos];
- if (r.pos<=0) throw new Error("called wrong form of reduce()");
- int pos = r.pos-1;
- n.reduce(r, pos, n.phase(), holder, n2);
- }
- }
-
- public void reduce(Position r, int pos, Phase target, Forest[] holder) { reduce(r, pos, target, holder, null); }
- public void reduce(Position r, int pos, Phase target, Forest[] holder, Node only) {
- Forest old = holder[pos];
- holder[pos] = this.pending();
- if (pos==0) {
- System.arraycopy(holder, 0, r.holder, 0, holder.length);
- for(int i=0; i<r.pos; i++) if (r.holder[i]==null) throw new Error("realbad");
- Forest rex = null;
-
- // FIXME: I'm unsure about this -- basically we want to deal with the case where
- // there are two nodes, each of whose Ref points to the same Forest instance.
- // Some node in the next phase has both of these as parents. This might happen
- // since the same reduction can appear in more than one state.
- if (r.pos==1) rex = singularReductions.get(this.pending(), r);
- if (rex==null) {
- rex = r.rewrite(phase().getLocation());
- if (r.pos==1) singularReductions.put(this.pending(), r, rex);
- }
- if (only != null) only.finish(r, rex, target, holder);
- else for(Node child : this.parents()) child.finish(r, rex, target, holder);
- } else {
- if (only != null) only.reduce(r, pos-1, target, holder);
- else for(Node child : this.parents()) child.reduce(r, pos-1, target, holder);
- }
- holder[pos] = old;
- }
-
- public void finish(Position r, Forest result, Phase<Tok> target, Forest[] holder) {
- Parser.Table<Tok>.State<Tok> state0 = state.gotoSetNonTerminals.get(r.owner());
- if (result==null) throw new Error();
- if (state0!=null)
- target.newNode(this, result, state0, r.pos<=0, r);
- }
-
- private Node(Node parent, Forest pending, State state) {
- this.state = state;
- this.holder().merge(pending);
- Phase start = parent==null ? null : parent.phase();
- if (parent != null) parents().add(parent, true);
- if (Phase.this.hash.get(state, start) != null) throw new Error("severe problem!");
- Phase.this.hash.put(state, start, this);
- }
- public int toInt() { return idx; }
- private final int idx = node_idx++;
- }
- private int node_idx = 0;
-
public int toInt() { return pos+1; }
public int size() { return hash==null ? 0 : hash.size(); }
+ public int pos() { return pos; }
+ public Tok getToken() { return token; }
+ public Iterator<Node> iterator() { return hash.iterator(); }
+ public GSS getGSS() { return GSS.this; }
+
+ // GraphViz //////////////////////////////////////////////////////////////////////////////
+
+ public GraphViz.Node toGraphViz(GraphViz gv) {
+ if (gv.hasNode(this)) return gv.createNode(this);
+ GraphViz.Group g = gv.createGroup(this);
+ g.label = "Phase " + pos;
+ g.color = "gray";
+ g.cluster = true;
+ return g;
+ }
+ public boolean isTransparent() { return false; }
+ public boolean isHidden() { return false; }
+
}
}