+// 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.*;
public Walk() { this(null); }
public Walk(Cache c) { this.c = c; }
- public T sequence(Sequence s) {
+ public T walkSequence(Sequence s) {
T ret = bottom(s);
for(Position p = s.firstp(); p!=null && !p.isLast(); p = p.next())
ret = sequence(s, ret, walk(p.element()));
protected T walk2(SequenceOrElement e) {
if (e instanceof Atom) return walkAtom((Atom)e);
- else if (e instanceof Sequence) return sequence((Sequence)e);
+ else if (e instanceof Sequence) return walkSequence((Sequence)e);
else if (e instanceof Union) {
T ret = bottom(e);
- for(Sequence s : (Union)e) {
+ for(Sequence s : (Union)e)
ret = union((Union)e, ret, walk(s));
-
- // FIXME
- for(Sequence ss : s.needs()) ret = union((Union)e, ret, walk(ss));
- for(Sequence ss : s.hates()) ret = union((Union)e, ret, walk(ss));
- }
return ret;
} else {
throw new Error("unknown element of class " + e.getClass().getName() + ": " + e);
public final HashSet<SequenceOrElement> walk() { return walk(e); }
public YieldSet(SequenceOrElement e, Cache c) { super(c); this.e = e; }
public HashSet<SequenceOrElement> bottom(SequenceOrElement e) { return acc; }
- public HashSet<SequenceOrElement> sequence(Sequence seq) { return bottom(seq); }
+ public HashSet<SequenceOrElement> walkSequence(Sequence seq) { return bottom(seq); }
public HashSet<SequenceOrElement> walkAtom(Atom r) {
c.atoms.put(e, c.atoms.get(e)==null ? r : c.atoms.get(e).union(r));
return super.walkAtom(r);
}
+ protected HashSet<SequenceOrElement> walk2(SequenceOrElement e) {
+ HashSet<SequenceOrElement> ret = super.walk2(e);
+ if (e instanceof Union)
+ for(Sequence s : (Union)e) {
+ for(Sequence ss : s.needs()) ret = union((Union)e, ret, walk(ss));
+ for(Sequence ss : s.hates()) ret = union((Union)e, ret, walk(ss));
+ }
+ return ret;
+ }
+ }
+
+ static class YieldSet2 extends Walk<HashSet<SequenceOrElement>> {
+ private final SequenceOrElement e;
+ public final HashSet<SequenceOrElement> walk() { return walk(e); }
+ public YieldSet2(SequenceOrElement e, Cache c) { super(c); this.e = e; }
+ public HashSet<SequenceOrElement> bottom(SequenceOrElement e) { return acc; }
+ public HashSet<SequenceOrElement> walkSequence(Sequence seq) { return bottom(seq); }
+ public HashSet<SequenceOrElement> walkAtom(Atom r) {
+ c.atoms.put(e, c.atoms.get(e)==null ? r : c.atoms.get(e).union(r));
+ return super.walkAtom(r);
+ }
+ }
+
+ static class EquivalentTo extends Walk<HashSet<Sequence>> {
+ private final Sequence s;
+ private final HashSet<Sequence> eq = new HashSet<Sequence>();
+ public final HashSet<Sequence> walk() { return walk(s); }
+ public EquivalentTo(Sequence e, Cache c) {
+ super(c); this.s = e;
+ }
+ public HashSet<Sequence> bottom(SequenceOrElement e) { return eq; }
+ public HashSet<Sequence> walkSequence(Sequence seq) {
+ eq.add(seq);
+ Position p = seq.firstp();
+ for(; !p.isLast(); p = p.next()) {
+ if (!p.isLast() && isRightNullable(p.next()))
+ walk(p.element());
+ if (!c.possiblyEpsilon(p.element())) break;
+ }
+ return eq;
+ }
+ public HashSet<Sequence> walkAtom(Atom r) {
+ return eq;
+ }
+ private boolean isRightNullable(Position p) {
+ if (p.isLast()) return true;
+ if (!c.possiblyEpsilon(p.element())) return false;
+ return isRightNullable(p.next());
+ }
}
}
}
+ static class EpsilonFollowSet extends Walk<Atom> {
+ Atom all;
+ Atom empty;
+ public EpsilonFollowSet(Atom a, Atom empty, Cache c) {
+ super(c);
+ this.all = all;
+ this.empty = empty;
+ }
+ public Atom walkAtom(Atom r) { return all; }
+ public Atom walkSequence(Sequence s) {
+ if (s.follow==null) return all;
+ return s.follow;
+ }
+ public Atom sequence(Sequence s, Atom a, Atom b) {
+ throw new RuntimeException();
+ }
+ public Atom union(Union u, Atom a, Atom b) {
+ /*
+ if (a==null) return b;
+ if (b==null) return a;
+ */
+ if (a==null || b==null) return all;
+ return (Atom)a.union(b);
+ }
+ public Atom bottom(SequenceOrElement e) {
+ return (e instanceof Union) ? empty : all;
+ }
+ }
// Input-Set //////////////////////////////////////////////////////////////////////////////
public Topology<Tok> walkAtom(Atom r) { cs = cs.union(r.getTokenTopology()); return cs; }
}
+ // feature: intersect with "first" set of all positive conjuncts
static class First<Tok extends Input> extends WalkTokenSet<Tok> {
public First(Topology<Tok> cs, Walk.Cache cache) { super(cs, cache); }
- public Topology<Tok> sequence(Sequence seq) {
+ public Topology<Tok> walkSequence(Sequence seq) {
for(Position p = seq.firstp(); p!=null && !p.isLast(); p = p.next()) {
walk(p.element());
if (!c.possiblyEpsilon(p.element())) break;
private final HashSet<SequenceOrElement> all;
private boolean eof = false;
public boolean includesEof() { return eof; }
- public Follow(Topology<Tok> cs, SequenceOrElement me, HashSet<SequenceOrElement> all, Cache c) { super(cs, c); this.me = me; this.all = all; }
+ public Follow(Topology<Tok> cs, SequenceOrElement me, HashSet<SequenceOrElement> all, Cache c) {
+ super(cs, c); this.me = me; this.all = all; }
public Topology<Tok> bottom(SequenceOrElement e) { return cs; }
- public Topology<Tok> sequence(Sequence seq) { return cs; }
+ public Topology<Tok> walkSequence(Sequence seq) { return cs; }
public Topology<Tok> walkAtom(Atom r) { return walk((SequenceOrElement)r); }
public Topology<Tok> walk(SequenceOrElement e) {
if (acc.contains(e)) return bottom(e);
public HashMap<SequenceOrElement,Boolean> eof = new HashMap<SequenceOrElement,Boolean>();
public HashMap<SequenceOrElement,Topology> follow = new HashMap<SequenceOrElement,Topology>();
public HashMapBag<SequenceOrElement,SequenceOrElement> ys = new HashMapBag<SequenceOrElement,SequenceOrElement>();
+ public HashMapBag<SequenceOrElement,SequenceOrElement> ys2 = new HashMapBag<SequenceOrElement,SequenceOrElement>();
public HashMap<SequenceOrElement,Topology> atoms = new HashMap<SequenceOrElement,Topology>();
public <Tok extends Input> Topology<Tok> first(SequenceOrElement e, Topology<Tok> empty) {
return new Walk.First<Tok>(empty, this).walk(e);
projects / sbp.git / blobdiff