/** implements Tomita's Graph Structured Stack */
class GSS {
- static int count = 0;
- static int shifts = 0;
- static int reductions = 0;
- int resets = 0;
- int waits = 0;
-
Input input;
-
public GSS(Input input) { this.input = input; }
-
- private Phase.Node[] reducing_list = null;
+ public Input getInput() { return input; }
// FIXME: right now, these are the performance bottleneck
- HashMapBag<Sequence,Phase.Waiting> waiting = new HashMapBag<Sequence,Phase.Waiting>();
HashMapBag<Integer,Sequence> performed = new HashMapBag<Integer,Sequence>();
- HashMapBag<Integer,Sequence> lastperformed = new HashMapBag<Integer,Sequence>();
- HashMapBag<Integer,Sequence> expected = new HashMapBag<Integer,Sequence>();
-
+
/** FIXME */
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, GraphViz.ToGraphViz, Iterable<Phase.Node> {
+ class Phase<Tok> implements Invokable<State, Result, Object>, IntegerMappable, GraphViz.ToGraphViz, Iterable<Node> {
- public Iterator<Phase.Node> iterator() { return hash.iterator(); }
- public void invoke(State st, Forest result, Node n) {
- shifts++;
- 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 boolean closed;
+ public IntPairMap<Node> hash; /* ALLOC */
private boolean good;
private Phase next = null;
private Phase prev;
private Input.Location nextLocation;
private Input.Location prevLocation;
- public final Parser parser;
-
private Forest forest;
- public Phase(Phase prev, Parser parser, Phase previous, Tok token, Input.Location location,
+ 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;
this.nextLocation = nextLocation;
performed.clear();
- reset();
- }
-
- public void reset() throws ParseFailed {
- waiting.clear();
- expected.clear();
- lastperformed.clear();
- lastperformed.addAll(performed);
- performed.clear();
- hash = new IntPairMap<Phase.Node>();
- reset = false;
+ 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)
- ParseFailed.error("unexpected end of file",
- getLocation(),
- token,
- hash.values(),
- getLocation().createRegion(getLocation()),
- input,
- GSS.this);
+ ParseFailed.error("unexpected end of file", this);
return true;
}
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);
+ }
+ 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 result the SPPF result corresponding to 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 (owner.hates!=null) {
- for (Sequence s : performed.getAll(pos))
- if (owner.hates.contains(s))
- return;
- for (Sequence s : lastperformed.getAll(pos))
- if (owner.hates.contains(s)) {
- //System.out.println("now expecting ["+pos+"] => " + s);
- expected.add(pos, s);
- 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 (!performed.contains(pos, owner)) {
- performed.add(pos, owner);
- if (owner.hated != null)
- for(Sequence seq : owner.hated)
- if (performed.contains(pos, seq)) {
- performed.remove(pos, seq);
- reset = true;
- }
- }
- }
- newNode(parent, pending, state, fromEmptyReduction);
- 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) {
- if (p.merge(parent, pending)) 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;
}
- LinkedList<Node> reductionQueue = new LinkedList<Node>();
-
- /** 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++) {
- reductionQueue.add(reducing_list[i]);
- reducing_list[i] = null;
- }
- while(!reductionQueue.isEmpty()) {
- reductionQueue.remove().performReductions();
- }
- if (reset) {
- reset = false;
- resets++;
- throw new Reset();
- }
- for(int i : expected)
- for(Sequence s : expected.getAll(i))
- if (!performed.contains(i, s)) {
- //System.out.println("resetting due to pos="+i+": " + s + " " + System.identityHashCode(s));
- resets++;
- throw new Reset();
- }
- } catch (Reset r) {
- reset();
- reduce();
- }
- count = 0;
- }
-
- private boolean reset = false;
- 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 && parser.helpgc) {
- prev.hash = 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.Many();
- for(Object f : n.results())
- finalResult.merge((Forest)f);
- }
- if (token == null) continue;
- n.state.invokeShifts(token, this, result, n);
- }
-
- if (!good && token!=null)
- ParseFailed.error("unexpected character",
- getLocation(),
- token,
- hash.values(),
- getRegion(),
- input,
- GSS.this);
-
- if (token==null && finalResult==null)
- ParseFailed.error("unexpected end of file",
- getLocation(),
- token,
- hash.values(),
- getLocation().createRegion(getLocation()),
- input,
- GSS.this);
- }
-
-
- 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 */
- final class Node implements Invokable<Position, Node, Node>, IntegerMappable, GraphViz.ToGraphViz {
- public FastSet<Node> set = new FastSet<Node>();
- 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; }
-
- private HashSet<Forest.Many> resultMap = new HashSet<Forest.Many>();
- public Iterable<Forest.Many> results() { return resultMap; }
- public FastSet<Node> parents() { return set; }
- public boolean merge(Node parent, Forest result) {
- // FIXME: inefficient!
- for(Forest.Many f : results()) {
- if (f.parents.contains(parent) /* UGLY: */ && f.parents.size()==1) {
- f.merge(result);
- return true;
- }
- }
- Forest.Many f = new Forest.Many();
- f.parents.add(parent);
- f.merge(result);
- resultMap.add(f);
- set.add(parent, true);
- return false;
- }
-
- public void performReductions() {
- if (allqueued) return;
- allqueued = true;
- state.invokeReductions(token, this, this, null);
- }
-
- public void performReductions(Node n2) {
- if (!allqueued) reductionQueue.add(this);//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) {
- reductions++;
- 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().getLocation().createRegion(n.phase().getLocation())), n.phase());
- else n.reduce(r, r.pos-1, n.phase(), null);
- } else {
- if (r.pos<=0) throw new Error("called wrong form of reduce()");
- int pos = r.pos-1;
- n.reduce(r, pos, n.phase(), n2);
- }
- }
-
- public void reduce(Position r, int pos, Phase target, Node only) {
- Forest[] holder = r.holder;
- Forest old = holder[pos];
-
- HashSet<Forest> rr = new HashSet<Forest>();
- for(Forest result : results()) rr.add(result);
- for(Forest result : rr)
- for(Node child : ((Forest.Many<?>)result).parents) {
- if (only != null && child!=only) continue;
- holder[pos] = result;
- if (pos==0) child.finish(r, r.rewrite(child.phase().getLocation().createRegion(target.getLocation())), target);
- else child.reduce(r, pos-1, target, null);
- }
-
- holder[pos] = old;
- }
-
- public void finish(Position r, Forest result, Phase<Tok> target) {
- 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.merge(parent, 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++;
-
- // GraphViz //////////////////////////////////////////////////////////////////////////////
-
- public GraphViz.Node toGraphViz(GraphViz gv) {
- if (gv.hasNode(this)) return gv.createNode(this);
- GraphViz.Node n = gv.createNode(this);
- n.label = ""+state.toStringx();
- n.shape = "rectangle";
- n.fill = "green";
- for(Forest result : results()) n.edge(result, "");
- for(Node parent : parents()) n.edge(parent, "");
- ((GraphViz.Group)phase().toGraphViz(gv)).add(n);
- return n;
- }
- public boolean isTransparent() { return false; }
- public boolean isHidden() { return false; }
-
- }
- 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 boolean isHidden() { return false; }
}
+
}
projects / sbp.git / blobdiff