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.Sequence.Position;
+import edu.berkeley.sbp.Parser.Table.State;
+import edu.berkeley.sbp.Parser.Table.Reduction;
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)
-//
-// - most of our time is now spent creating and storing Reduct instances
-// - we should be able to perform Reduct's immediately after creating them...
-//
-
/** implements Tomita's Graph Structured Stack */
class GSS {
public GSS() { }
+ private Phase.Node[] reducing_list = null;
+ public int resets = 0;
+ public int waits = 0;
+
+ HashMapBag<Integer,Sequence> inhibited = new HashMapBag<Integer,Sequence>();
+ HashMapBag<Integer,Sequence> assumed = new HashMapBag<Integer,Sequence>();
+ HashMapBag<Sequence,Phase.Waiting> waiting = new HashMapBag<Sequence,Phase.Waiting>();
+ HashMapBag<Integer,Sequence> performed = new HashMapBag<Integer,Sequence>();
+ HashSet<Phase.Waiting> tail = new HashSet<Phase.Waiting>();
+
/** corresponds to a positions <i>between tokens</i> the input stream; same as Tomita's U_i's */
- public class Phase {
+ public class Phase implements Invokable<State, Forest, GSS.Phase.Node>, IntegerMappable {
+ public int toInt() { return pos+1; }
/** the token immediately after this phase */
public final Token token;
+ boolean reducing;
+
/** currently this is necessary only for the code() hack -- it doesn't actually correspond to the input */
private final int pos;
/** FIXME */
- public Forest.Ref finalResult = null;
-
- /** all reductions (pending and completed) */
- private HashSet<Phase.Reduct> reductions = new HashSet<Phase.Reduct>(); /* ALLOC */
+ public Forest.Ref finalResult;
/** all nodes, keyed by the value returned by code() */
- private HashMap<Long,Phase.Node> hash = new HashMap<Long,Phase.Node>(); /* ALLOC */
-
- /** the number of pending reductions */
- private int pendingReductions = 0;
- private int totalReductions = 0;
- private HashSet<Reduct> pendingReduct = new HashSet<Reduct>();
+ /*private*/ IntPairMap<Phase.Node> hash; /* ALLOC */
/** the number of nodes in this phase */
- private int numNodes = 0;
+ private int numNodes;
+
+ boolean closed;
- boolean closed = false;
+ private boolean good;
+ private Phase next = null;
private Token.Location location;
- public Phase(Phase previous, Token token, Token.Location location) {
+ public final Parser parser;
+
+ private Forest forest;
+ Phase prev;
+ public Phase(Phase prev, Parser parser, Phase previous, Token token, Token.Location location, Forest forest) {
+ 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();
+ assumed.clear();
+ reset();
+ }
+
+ public void reset() {
+ tail.clear();
+ waiting.clear();
+ performed.clear();
+ hash = new IntPairMap<Phase.Node>();
+ good = false;
+ closed = false;
+ numNodes = 0;
+ reducing = false;
+ finalResult = null;
+ if (prev != null) prev.shift(this, forest);
}
- public boolean isDone() { return token == null; }
+ public void complain(Node n, HashMap<String,HashSet<String>> errors, boolean force) {
+ if (n.touched) return;
+ n.touched = true;
+ for(Position p : n.state) {
+ //if (!p.isLast()) {
+ if (((p.isFirst() || p.isLast()) && !force) || p.owner().name==null) {
+ for(Node n2 : n.parents())
+ complain(n2, errors, force | p.isFirst());
+ } else {
+ String seqname = p.owner().name;
+ HashSet<String> hs = errors.get(seqname);
+ if (hs==null) errors.put(seqname, hs = new HashSet<String>());
+ hs.add(p.element()+"");
+ //String s = " while parsing " + seqname + ": expected a " + p.element();
+ //"\n";
+ /*
+ s += " parsed: ";
+ for(Position p2 = p.owner().firstp(); p2 != null && p2 != p && !p2.isLast(); p2 = p2.next()) s += (p2.element() + " ");
+ s += "\n";
+ s += " expected: ";
+ for(Position p2 = p; p2 != null && !p2.isLast(); p2 = p2.next()) s += (p2.element() + " ");
+ */
+ //s += "\n";
+ //errors.add(s);
+ }
+ }
+ }
- private String error = "generic syntax error";
- public void checkFailure() throws Parser.Failed {
- if (numNodes <= 0)
- throw new Parser.Failed(error, getLocation());
+ public String black(Object o) { return "\033[30m"+o+"\033[0m"; }
+ public String red(Object o) { return "\033[31m"+o+"\033[0m"; }
+ public String green(Object o) { return "\033[32m"+o+"\033[0m"; }
+ public String yellow(Object o) { return "\033[33m"+o+"\033[0m"; }
+ public String blue(Object o) { return "\033[34m"+o+"\033[0m"; }
+ public String purple(Object o) { return "\033[35m"+o+"\033[0m"; }
+ public String cyan(Object o) { return "\033[36m"+o+"\033[0m"; }
+ public String el(Object e) {
+ String s = e.toString();
+ if (s.length()==0 || s.charAt(0)!='\"' || s.charAt(s.length()-1)!='\"') return yellow(s);
+ s = s.substring(1);
+ s = s.substring(0, s.length()-1);
+ StringBuffer ret = new StringBuffer();
+ for(int i=0; i<s.length(); i++) {
+ if (s.charAt(i)=='\\' && i<s.length()-1) ret.append(s.charAt(++i));
+ else ret.append(s);
+ }
+ return purple(ret.toString());
+ }
+ public String error(String message) {
+ String lookAhead = token==null ? "<EOF>" : token.toString();
+ StringBuffer ret = new StringBuffer();
+ ret.append("\n ");
+ ret.append(message);
+ HashMap<String,HashSet<String>> errors = new HashMap<String,HashSet<String>>();
+ for(Node n : hash.values()) {
+ //System.out.println(n.state);
+ complain(n, errors, false);
+ }
+ for(String s : errors.keySet()) {
+ ret.append(" while parsing " + yellow(s));
+ HashSet<String> hs = errors.get(s);
+ if (hs.size()==1) ret.append(" expected " + yellow(el(hs.iterator().next())) + "\n");
+ else {
+ ret.append(" expected ");
+ boolean first = true;
+ for(String s2 : hs) {
+ if (!first) ret.append(" or ");
+ first = false;
+ ret.append(yellow(el(s2)));
+ }
+ ret.append("\n");
+ }
+ }
+ return ret.toString();
+ }
+
+ public boolean isDone() throws ParseFailed {
+ if (token != null) return false;
+ if (token==null && finalResult==null)
+ throw new ParseFailed(error(red("unexpected end of file\n")),
+ getLocation());
+ return true;
}
public Token.Location getLocation() { return location; }
* @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);
+ 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, Reduction reduction) {
+ int pos = parent==null?0:parent.phase()==null?0:parent.phase().pos;
+ Sequence owner = reduction==null ? null : reduction.position.owner();
+ if (reduction!=null) {
+ if (inhibited.contains(pos, owner)) return;
+ /*
+ if (assumed.contains(pos, owner)) {
+ tail.add(new Waiting(parent, pending, state, fromEmptyReduction, reduction));
+ 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 void newNode2(Node p, Node parent, Forest pending, Parser.Table.State state, boolean fromEmptyReduction, Phase start) {
+ private boolean newNode2(Node p, Node parent, Forest pending, State state, boolean fromEmptyReduction) {
p.holder.merge(pending);
- if (p.parents.contains(parent)) return;
- p.parents.add(parent, true);
+ if (p.parents().contains(parent)) return true;
+ p.parents().add(parent, true);
if (p!=parent && !fromEmptyReduction) p.queueReductions(parent);
+ return true;
}
- private void newNode3(Node parent, Forest pending, Parser.Table.State state, boolean fromEmptyReduction, Phase start) {
+ private boolean newNode3(Node parent, Forest pending, State state, boolean fromEmptyReduction) {
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 (!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, start); // ALLOC
+ Node n = new Node(parent, pending, state, fromEmptyReduction); // ALLOC
n.queueEmptyReductions();
- if (!fromEmptyReduction) n.queueReductions();
+ if (!fromEmptyReduction) n.queueReductions(parent);
+ 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(Reduction r, int p) {
+ if (r.position.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.position.owner().hated) {
+ if (performed.contains(p,seq)) {
+ uninhibit(p, seq);
+ //System.out.println("\nresetting due to " + r.position.owner() + " killing " + seq);
+ //inhibited.clear();
+ inhibited.add(p, seq);
+ //assumed = inhibited;
+ //inhibited = new HashMapBag<Integer,Sequence>();
+ reset = true;
+ resets++;
+ throw new Reset();
+ }
+ inhibited.add(p, seq);
+ }
+ }
+
/** perform all reduction operations */
public void reduce() {
- for(Phase.Node n : hash.values()) {
- n.queueEmptyReductions();
- n.queueReductions();
+ 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.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();
+ }
+ //for(Waiting w : tail)
+ //w.perform();
+ } catch (Reset r) {
+ reset();
+ reduce();
}
- while(pendingReduct.size()>0)
- pendingReduct.iterator().next().go();
+ }
+
+ class Reset extends RuntimeException { }
+
+ public void invoke(State st, Forest result, Node n) {
+ good |= next.newNode(n, result, st, false);
}
/** perform all shift operations, adding promoted nodes to <tt>next</tt> */
- public void shift(Phase next, Forest result) {
+ public void shift(Phase next, Forest result) throws ParseFailed {
+ if (prev!=null) prev.hash = null;
+ this.next = next;
closed = true;
Forest res = null;
boolean ok = false;
for(Phase.Node n : hash.values()) {
- 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;
- }
+ n.state.invokeShifts(token, this, result, n);
}
- 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();
- }
+ if (!good && token!=null)
+ throw new ParseFailed(error(red("unexpected character")+" "+purple(token)+" encountered at "+green(getLocation())+"\n"),
+ getLocation());
+ if (token==null && finalResult==null)
+ throw new ParseFailed(error(red("unexpected end of file\n")),
+ getLocation());
// this massively improves GC performance
- reductions = null;
- hash = null;
+ //hash = null;
}
+
+ public class Waiting {
+ Node parent;
+ Forest pending;
+ State state;
+ boolean fromEmptyReduction;
+ Reduction reduction;
+ public Waiting(Node parent, Forest pending, State state, boolean fromEmptyReduction, Reduction 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);
+ }
+ }
// GSS Nodes //////////////////////////////////////////////////////////////////////////////
- private HashMap<Parser.Table.Reduction,Forest> pcache = new HashMap<Parser.Table.Reduction,Forest>();
/** a node in the GSS */
- public class Node {
+ public final class Node extends FastSet<Node> implements Invokable<Reduction, Node, Node> {
+ public boolean touched = false;
private Forest.Ref holder = null;
-
- private HashMap<Parser.Table.Reduction,Forest> cache = null;
-
- /** the set of nodes to which there is an edge starting at this node */
- public final FastSet<Node> parents = new FastSet<Node>(); /* ALLOC */
-
+ private boolean allqueued = false;
/** what state this node is in */
- public final Parser.Table.State state;
+ public final State state;
+
/** which Phase this Node belongs to (node that Node is also a non-static inner class of Phase) */
- public final Phase phase = Phase.this;
+ public Phase phase() { return Phase.this; }
- public HashMap<Parser.Table.Reduction,Forest> cache() { return cache==null ? (cache = new HashMap<Parser.Table.Reduction,Forest>()) : cache; }
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 parents; }
+ public FastSet<Node> parents() { return this; }
- /** FIXME */
public void queueReductions() {
- for(Node n2 : parents)
- queueReductions(n2);
+ if (!reducing) return;
+ if (allqueued) return;
+ allqueued = true;
+ int where = parents().size();
+ state.invokeReductions(token, this, this, null);
}
- /** FIXME */
public void queueReductions(Node n2) {
- new Reduct(this, n2, null);
- for(Parser.Table.Reduction r : token==null ? state.getEofReductions() : state.getReductions(token)) {
-
- // currently we have this weird problem where we
- // have to do an individual reduct for each child
- // when the reduction length is one (ie the
- // children wind up being children of the newly
- // created node rather than part of the popped
- // sequence
+ if (!allqueued) { queueReductions(); return; }
+ state.invokeReductions(token, this, this, n2);
+ }
- if (r.numPop == 1) new Reduct(this, n2, r);
+ public final void invoke(Reduction r, Node n, Node n2) {
+ if (n==null) {
+ if (r.numPop==0) r.reduce(this);
+ return;
}
+ if (r.numPop==0) return;
+ if (n2==null) r.reduce(n);
+ else r.reduce(n, n2);
}
-
-
- /** FIXME */
public void queueEmptyReductions() {
- for(Parser.Table.Reduction r : token==null ? state.getEofReductions() : state.getReductions(token)) {
- if (r.numPop==0)
- new Reduct(this, null, r); /* ALLOC */
- }
+ if (!reducing) return;
+ state.invokeReductions(token, this, null, null);
}
- private Node(Node parent, Forest pending, Parser.Table.State state, Phase start) {
+ private boolean fe;
+ public boolean dead = false;
+ public boolean redo = false;
+ private Node(Node parent, Forest pending, State state, boolean fe) {
+ this.fe = fe;
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);
+ 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);
Phase.this.numNodes++;
- if (parent==null) holder().valid = true; // hack to make sure that the "base" node is always considered valid
- }
- }
-
-
- // Forest / Completed Reductions //////////////////////////////////////////////////////////////////////////////
-
- /** a pending or completed reduction */
- class Reduct {
-
- /** the node from which the reduction should begin */
- public Node n = null;
-
- /** the node on the other end of the edge to be reduced along (either: null, the second node of the reduction,
- * or the parent of the result of a length-one reduction)
- */
- public Node n2 = null;
-
- /** true iff the reduction has already been performed */
- private boolean done = false;
-
- /** the reduction to be applied */
- public Parser.Table.Reduction r;
-
- public Tree<String> result = null;
-
- public Reduct(Node n, Node n2, Parser.Table.Reduction r) {
- this.n = n;
- this.n2 = n2;
- this.r = r;
- if (reductions.contains(this)) { done = true; return; }
- reductions.add(this);
- pendingReduct.add(this);
- pendingReductions++;
- }
-
- /** perform the reduction */
- public void go() {
- if (done) return;
- done = true;
- pendingReduct.remove(this);
- pendingReductions--;
-
- // FIXME: explain this
- if (r==null) {
- for(Parser.Table.Reduction r : token==null ? n.state.getEofReductions() : n.state.getReductions(token)) {
- if (r.numPop <= 1) continue;
- r.reduce(n, n2, Phase.this, null);
- }
- } else if (r.numPop<=1) {
- // UGLY HACK
- // The problem here is that a "reduction of length 0/1"
- // performed twice with different values of n2 needs
- // to only create a *single* new result, but must add
- // multiple parents to the node holding that result.
- // The current reducer doesn't differentiate between
- // the next node of an n-pop reduction and the
- // ultimate parent of the last pop, so we need to
- // cache instances here as a way of avoiding
- // recreating them.
-
- Forest ret = (r.numPop==0 ? pcache : n.cache()).get(r);
- if (ret != null) r.reduce(n, n2, n.phase, ret);
- else (r.numPop==0 ? pcache : n.cache()).put(r, r.reduce(n, n2, n.phase, null));
-
- } else {
- r.reduce(n, n2, Phase.this, null);
- }
- }
-
- // FIXME: this is a PITA
- public int hashCode() { return n.hashCode() ^ (r==null ? 0 : r.hashCode()) ^ (n2==null ? 0 : n2.hashCode()); }
- public boolean equals(Object o) {
- if (o==null) return false;
- if (o==this) return true;
- if (!(o instanceof Reduct)) return false;
- Reduct other = (Reduct)o;
- return equal(r, other.r) && equal(n, other.n) && equal(n2, other.n2);
}
}
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);
- }
-
}