package edu.berkeley.sbp;
import edu.berkeley.sbp.*;
import edu.berkeley.sbp.util.*;
-import edu.berkeley.sbp.*;
import edu.berkeley.sbp.Sequence.Position;
-import edu.berkeley.sbp.*;
import java.io.*;
import java.util.*;
-import java.lang.reflect.*;
/** a parser which translates streams of Tokens of type T into a Forest<R> */
public abstract class Parser<T extends Token, R> {
/** create a parser to parse the grammar with start symbol <tt>u</tt> */
protected Parser(Union u) { this.pt = new Table(u, top()); }
- protected Parser(Table pt) { this.pt = pt; }
+ //protected Parser(Table pt) { this.pt = pt; }
+ /** implement this method to create the output forest corresponding to a lone shifted input token */
public abstract Forest<R> shiftedToken(T t, Token.Location loc);
- public abstract Topology<T> top();
+ /** this method must return an empty topology of the input token type */
+ public abstract Topology<T> top();
- /** parse <tt>input</tt> for a exactly one unique result, throwing <tt>Ambiguous</tt> if not unique or <tt>Failed</tt> if none */
- public Tree<R> parse1(Token.Stream<T> input) throws IOException, Failed, Ambiguous {
+ /** parse <tt>input</tt> for a exactly one unique result, throwing <tt>Ambiguous</tt> if not unique or <tt>ParseFailed</tt> if none */
+ public Tree<R> parse1(Token.Stream<T> input) throws IOException, ParseFailed, Ambiguous {
Forest<R> ret = parse(input);
try { return ret.expand1(); }
catch (Ambiguous a) {
}
/** parse <tt>input</tt>, using the table <tt>pt</tt> to drive the parser */
- public Forest<R> parse(Token.Stream<T> input) throws IOException, Failed {
+ public Forest<R> parse(Token.Stream<T> input) throws IOException, ParseFailed {
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, this, null, input.next(1, 0, 0), loc, null);
+ current.newNode(null, Forest.leaf(null, null), pt.start, true);
+ int count = 1;
for(;;) {
loc = input.getLocation();
- GSS.Phase next = gss.new Phase(current, input.next(), loc);
current.reduce();
Forest forest = current.token==null ? null : shiftedToken((T)current.token, loc);
- current.shift(next, forest);
+ GSS.Phase next = gss.new Phase(current, this, current, input.next(count, gss.resets, gss.waits), loc, forest);
+ count = next.hash.size();
if (current.isDone()) return (Forest<R>)current.finalResult;
- current.checkFailure();
current = next;
}
}
// Exceptions //////////////////////////////////////////////////////////////////////////////
- public static class Failed extends Exception {
- private final Token.Location location;
- private final String message;
- public Failed() { this("", null); }
- public Failed(String message, Token.Location loc) { this.location = loc; this.message = message; }
- public Token.Location getLocation() { return location; }
- public String toString() { return message + (location==null ? "" : (" at " + location)); }
- }
-
- public static class Ambiguous extends RuntimeException {
- public final Forest ambiguity;
- public Ambiguous(Forest ambiguity) { this.ambiguity = ambiguity; }
- public String toString() {
- StringBuffer sb = new StringBuffer();
- sb.append("unresolved ambiguity "/*"at " + ambiguity.getLocation() + ":"*/);
- for(Object result : ambiguity.expand(false))
- sb.append("\n " + result);
- return sb.toString();
- }
- }
-
// Table //////////////////////////////////////////////////////////////////////////////
static class Table extends Walk.Cache {
public final Walk.Cache cache = this;
+
+ public HashMapBag<Position,State> byPosition = new HashMapBag<Position,State>();
private void walk(Element e, HashSet<Element> hs) {
if (e==null) return;
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 */
- public class State implements Comparable<Table.State>, Iterable<Position> {
+
+ public class State implements Comparable<Table.State>, IntegerMappable, Iterable<Position> {
+ public int toInt() { return idx; }
+
+ public boolean lame() {
+ for(Position p : this)
+ for(Position p2 = p; p2!=null; p2=p2.next())
+ if (p2.isLast() && !p2.owner().lame)
+ return false;
+ return true;
+ }
/*
public boolean isResolvable(Token t) {
boolean found = false;
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 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 //////////////////////////////////////////////////////////////////////////////
/**
// register ourselves in the all_states hash so that no
// two states are ever created with an identical position set
all_states.put(hs, this);
+ for(Position p : hs) byPosition.add(p,this);
// Step 1a: examine all Position's in this state and compute the mappings from
// sets of follow tokens (tokens which could follow this position) to sets
}
}
- public String toString() { return "state["+idx+"]"; }
+ public String toString() {
+ //return "state["+idx+"]";
+ StringBuffer ret = new StringBuffer();
+ ret.append("state["+idx+"]: ");
+ for(Position p : this) ret.append("{"+p+"} ");
+ return ret.toString();
+ }
public int compareTo(Table.State s) { return idx==s.idx ? 0 : idx < s.idx ? -1 : 1; }
}
this.holder = new Forest[numPop];
}
public String toString() { return "[reduce " + position + "]"; }
- public Forest reduce(Forest f, GSS.Phase.Node parent, GSS.Phase.Node onlychild, GSS.Phase target, Forest rex) {
- holder[numPop-1] = f;
- return reduce(parent, numPop-2, rex, onlychild, target);
- }
- public Forest reduce(GSS.Phase.Node parent, GSS.Phase.Node onlychild, Forest rex) {
- return reduce(parent, numPop-1, rex, onlychild, parent.phase());
- }
private Forest zero = null;
public Forest zero() {
return zero = position.rewrite(null);
}
- // 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();
- if (pos<=0 && rex==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);
- rex = position.rewrite(target.getLocation());
+ finish(onlychild, position.rewrite(parent.phase().getLocation()), parent.phase());
+ } else {
+ reduce(onlychild, pos-1, parent.phase());
}
- 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);
+ holder[pos] = old;
+ }
+
+ // FIXME: this could be more elegant and/or cleaner and/or somewhere else
+ private void reduce(GSS.Phase.Node parent, int pos, GSS.Phase target) {
+ Forest old = holder[pos];
+ holder[pos] = parent.pending();
+ if (pos==0) {
+ 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 (result==null) throw new Error();
+ if (state!=null)
+ target.newNode(parent, result, state, numPop<=0, this);
}
}
}
projects / sbp.git / blobdiff