+// Copyright 2006 all rights reserved; see LICENSE file for BSD-style license
+
package edu.berkeley.sbp;
import edu.berkeley.sbp.*;
-import edu.berkeley.sbp.*;
-import edu.berkeley.sbp.*;
import edu.berkeley.sbp.util.*;
+import edu.berkeley.sbp.Parser.Table.*;
+import edu.berkeley.sbp.Sequence.Position;
import java.io.*;
import java.util.*;
import java.lang.reflect.*;
-//////////////////////////////////////////////////////////////////////////////
-// TODO:
-//
-// - fix public/package/private status
-//
-
-//////////////////////////////////////////////////////////////////////////////
-// Optimizations to add
-//
-// ** NOTE: not all of these are appropriate for this class -- it is
-// simply a list of optimizations not implemented. This
-// class is meant to remain simple and easy to understand;
-// optimizations which obscure that do not belong here (they
-// should go into the compiled version instead)
-
/** implements Tomita's Graph Structured Stack */
class GSS {
- public GSS() { }
-
- private Phase.Node[] reducing_list = null;
-
- /** corresponds to a positions <i>between tokens</i> the input stream; same as Tomita's U_i's */
- public class Phase {
-
- /** the token immediately after this phase */
- public final Token token;
+ Input input;
+ public GSS(Input input) { this.input = input; }
+ public Input getInput() { return input; }
- boolean reducing = false;
+ // FIXME: right now, these are the performance bottleneck
+ HashMapBag<Integer,Sequence> performed = new HashMapBag<Integer,Sequence>();
- /** currently this is necessary only for the code() hack -- it doesn't actually correspond to the input */
- private final int pos;
+ /** FIXME */
+ Forest.Many finalResult;
- /** FIXME */
- public Forest.Ref finalResult = null;
+ /** corresponds to a positions <i>between tokens</i> the input stream; same as Tomita's U_i's */
+ class Phase<Tok> implements Invokable<State, Result, Object>, IntegerMappable, GraphViz.ToGraphViz, Iterable<Node> {
- /** all nodes, keyed by the value returned by code() */
- private HashMap<Long,Phase.Node> hash = new HashMap<Long,Phase.Node>(); /* ALLOC */
+ public PriorityQueue<Reduction> reductionQueue = new PriorityQueue<Reduction>();
- /** the number of nodes in this phase */
- private int numNodes = 0;
+ public void invoke(State st, Result result, Object o) {
+ //shifts++;
+ good |= next.newNode(result, st, false);
+ }
- boolean closed = false;
+ /** the token immediately after this phase */
+ final Tok token;
+ final int pos;
+
+ public IntPairMap<Node> hash; /* ALLOC */
+ private boolean good;
+ private Phase next = null;
+ private Phase prev;
+ private Input.Location location;
+ private Input.Location nextLocation;
+ private Input.Location prevLocation;
+
+ private Forest forest;
- private Token.Location location;
- public Phase(Phase previous, Token token, Token.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.pos = previous==null ? 0 : previous.pos+1;
this.token = token;
this.location = location;
+ this.nextLocation = nextLocation;
+ performed.clear();
+ hash = new IntPairMap<Node>();
+ good = 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", this);
+ return true;
}
- public boolean isDone() { return token == null; }
+ 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);
+ }
+ if (!good && token!=null) ParseFailed.error("unexpected character", this);
+ if (token==null && finalResult==null) ParseFailed.error("unexpected end of file", this);
+ }
- private String error = "generic syntax error";
- public void checkFailure() throws Parser.Failed {
- if (numNodes <= 0)
- throw new Parser.Failed(error, getLocation());
+ /** perform all reduction operations */
+ public void reduce() throws ParseFailed {
+ while(!reductionQueue.isEmpty())
+ reductionQueue.poll().perform();
}
- public Token.Location getLocation() { return location; }
+ 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 void newNode(Node parent, Forest pending, Parser.Table.State state, boolean fromEmptyReduction, Phase start) {
- Node p = hash.get(code(state, start));
- if (p != null) newNode2(p, parent, pending, state, fromEmptyReduction, start);
- else newNode3(parent, pending, state, fromEmptyReduction, start);
- }
- private void newNode2(Node p, Node parent, Forest pending, Parser.Table.State state, boolean fromEmptyReduction, Phase start) {
- p.holder.merge(pending);
- if (p.parents().contains(parent)) return;
- p.addParent(parent, fromEmptyReduction);
- }
- private void newNode3(Node parent, Forest pending, Parser.Table.State state, boolean fromEmptyReduction, Phase start) {
+ 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;
- int count = 0;
- Parser.Table.Reduction r = null;
- for(Parser.Table.Reduction red : token==null ? state.getEofReductions() : state.getReductions(token)) { r = red; count++; }
- if (count==0) return; // BEWARE! this optimization is suspected to cause really nasty heisenbugs
- //if (count > 1) break;
- //if (r.numPop == 0) break;
- //r.reduce(pending, parent, null, Phase.this, null);
- //return;
+ if (!state.canReduce(token)) return false;
} while(false);
-
- Node n = new Node(parent, pending, state, start); // ALLOC
- n.queueEmptyReductions();
- if (!fromEmptyReduction) n.queueReductions(parent);
- }
-
-
- /** perform all reduction operations */
- public void reduce() {
- reducing = true;
- if (reducing_list==null || reducing_list.length < hash.size())
- reducing_list = new Phase.Node[hash.size() * 4];
- Collection<Node> hv = hash.values();
- hv.toArray(reducing_list);
- int num = hv.size();
- for(int i=0; i<num; i++) {
- Node n = reducing_list[i];
- n.queueEmptyReductions();
- // 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.queueReductions();
- }
- }
-
- /** perform all shift operations, adding promoted nodes to <tt>next</tt> */
- public void shift(Phase next, Forest result) {
- closed = true;
- Forest res = null;
- boolean ok = false;
- for(Phase.Node n : hash.values()) {
- if (n.holder==null) continue;
- n.holder.resolve();
- if (token == null && n.state.isAccepting()) {
- ok = true;
- if (finalResult==null) finalResult = new Forest.Ref();
- finalResult.merge(n.holder);
- }
- if (!n.holder.valid()) continue;
- if (token == null) continue;
- for(Parser.Table.State st : n.state.getShifts(token)) {
- if (res == null) res = result;
- next.newNode(n, res, st, true, this);
- ok = true;
- }
- }
-
- if (!ok && token != null) {
- StringBuffer error = new StringBuffer();
- error.append("error: unable to shift token \"" + token + "\"\n");
- //error.append(" before: " +pendingReductions+ "\n");
- //error.append(" before: " +totalReductions+ "\n");
- //for(Phase.Node n : hash.values()) {
- //n.queueReductions();
- //n.queueEmptyReductions();
- //}
- //error.append(" after: " +pendingReductions+ "\n");
- //error.append(" candidate states:\n");
- //for(Phase.Node n : hash.values()) {
- //for(Sequence.Position p : n.state) error.append(" " + p + "\n");
- //error.append(" --\n");
- //for(Parser.Table.Reduction r : n.state.getReductions(token)) error.append(" " + r + "\n");
- //error.append(" ==\n");
- //}
- next.error = error.toString();
- }
-
- // this massively improves GC performance
- hash = null;
+ new Node(Phase.this, result, state, fromEmptyReduction); // ALLOC
+ return true;
}
-
- // GSS Nodes //////////////////////////////////////////////////////////////////////////////
-
- /** a node in the GSS */
- public final class Node extends FastSet<Node> {
-
- public void addParent(Node parent, boolean fromEmptyReduction) {
- parents().add(parent, true);
- if (this!=parent && !fromEmptyReduction) queueReductions(parent);
- }
-
- private Forest.Ref holder = null;
- private boolean allqueued = false;
-
- /** the set of nodes to which there is an edge starting at this node */
- //public final FastSet<Node> parents = new FastSet<Node>(); /* ALLOC */
-
- /** what state this node is in */
- public final Parser.Table.State 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 queueReductions() {
- if (allqueued) return;
- allqueued = true;
- int where = parents().size();
- for(Parser.Table.Reduction r : state.getReductions(token))
- if (r.numPop >= 1)
- r.reduce(this, null, null);
- }
-
- public void queueReductions(Node n2) {
- if (!allqueued) { queueReductions(); return; }
- for(Parser.Table.Reduction r : state.getReductions(token))
- if (r.numPop > 0)
- r.reduce(this, n2, null);
- }
-
-
- public void queueEmptyReductions() {
- if (reducing)
- for(Parser.Table.Reduction r : token==null ? state.getEofReductions() : state.getReductions(token))
- if (r.numPop==0)
- r.reduce(this, null, r.zero());
- }
-
- private Node(Node parent, Forest pending, Parser.Table.State state, Phase start) {
- this.state = state;
- if (pending != null) this.holder().merge(pending);
- if (parent != null) parents().add(parent, true);
- if (Phase.this.hash.get(code(state, start)) != null) throw new Error("severe problem!");
- Phase.this.hash.put(code(state, start), this);
- Phase.this.numNodes++;
- if (parent==null) holder().valid = true; // hack to make sure that the "base" node is always considered valid
- }
+ 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; }
}
- /** helper method */
- private static boolean equal(Object a, Object b) {
- if (a==null && b==null) return true;
- if (a==null || b==null) return false;
- return a.equals(b);
- }
-
- /** this is something of a hack right now */
- private static long code(Parser.Table.State state, Phase start) {
- return (((long)state.idx) << 32) | (start==null ? 0 : start.pos);
- }
}