+// Copyright 2006 all rights reserved; see LICENSE file for BSD-style license
+
package edu.berkeley.sbp;
-import edu.berkeley.sbp.util.*;
-import edu.berkeley.sbp.*;
import edu.berkeley.sbp.*;
+import edu.berkeley.sbp.util.*;
import edu.berkeley.sbp.Sequence.Position;
import java.io.*;
import java.util.*;
import java.lang.reflect.*;
import java.lang.ref.*;
-/** a traversal of the grammar performed by mapping from Elements to a lattice and computing the resulting LUB */
+/** a traversal of the grammar performed by mapping from SequenceOrElements to a lattice and computing the resulting LUB */
abstract class Walk<T> {
- protected HashSet<Element> acc = new HashSet<Element>();
- protected abstract T bottom(Element e);
+ protected HashSet<SequenceOrElement> acc = new HashSet<SequenceOrElement>();
+ protected abstract T bottom(SequenceOrElement e);
protected final Cache c;
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()));
public T walkAtom(Atom r) { return walk(r); }
public T union(Union u, T a, T b) { return bottom(u); }
public T sequence(Sequence s, T a, T b) { return bottom(s); }
- protected T walk(Element e) {
+ protected T walk(SequenceOrElement e) {
if (acc.contains(e)) return bottom(e);
acc.add(e);
return walk2(e);
}
- protected T walk2(Element e) {
+ 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) ret = union((Union)e, ret, walk(s));
+ for(Sequence s : (Union)e)
+ ret = union((Union)e, ret, walk(s));
return ret;
} else {
throw new Error("unknown element of class " + e.getClass().getName() + ": " + e);
}
}
- static class YieldSet extends Walk<HashSet<Element>> {
- private final Element e;
- public final HashSet<Element> walk() { return walk(e); }
- public YieldSet(Element e, Cache c) { super(c); this.e = e; }
- public HashSet<Element> bottom(Element e) { return acc; }
- public HashSet<Element> sequence(Sequence seq) { return bottom(seq); }
- public HashSet<Element> walkAtom(Atom r) {
- c.atoms.put(e, c.atoms.get(e)==null ? r.top() : c.atoms.get(e).union(r.top()));
+ static class YieldSet extends Walk<HashSet<SequenceOrElement>> {
+ private final SequenceOrElement 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> 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());
+ }
}
public Boolean walkAtom(Atom r) { return false; }
public Boolean sequence(Sequence s, Boolean a, Boolean b) { return new Boolean(a && b); }
public Boolean union(Union u, Boolean a, Boolean b) { return new Boolean(a || b); }
- public Boolean bottom(Element e) { return (e instanceof Union) ? false : true; }
- private HashMap<Element,Boolean> hm = new HashMap<Element,Boolean>();
- protected Boolean walk(Element e) {
+ public Boolean bottom(SequenceOrElement e) { return (e instanceof Union) ? false : true; }
+ private HashMap<SequenceOrElement,Boolean> hm = new HashMap<SequenceOrElement,Boolean>();
+ protected Boolean walk(SequenceOrElement e) {
if (hm.get(e) != null) return hm.get(e);
hm.put(e, false);
Boolean ret = walk2(e);
}
}
+ 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;
+ }
+ }
- // Token-Set //////////////////////////////////////////////////////////////////////////////
+ // Input-Set //////////////////////////////////////////////////////////////////////////////
- static abstract class WalkTokenSet<Tok extends Token> extends Walk<Topology<Tok>> {
+ static abstract class WalkTokenSet<Tok extends Input> extends Walk<Topology<Tok>> {
public Topology<Tok> cs;
public WalkTokenSet(Topology<Tok> cs) { this.cs = cs; }
public WalkTokenSet(Topology<Tok> cs, Cache c) { super(c); this.cs = cs; }
- public Topology<Tok> bottom(Element e) { return cs; }
- public Topology<Tok> walkAtom(Atom r) { cs.add(r.top()); return cs; }
+ public Topology<Tok> bottom(SequenceOrElement e) { return cs; }
+ public Topology<Tok> walkAtom(Atom r) { cs = cs.union(r.getTokenTopology()); return cs; }
}
- class First<Tok extends Token> extends WalkTokenSet<Tok> {
+ // 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 (!p.element().possiblyEpsilon(c)) break;
+ if (!c.possiblyEpsilon(p.element())) break;
}
return cs;
}
}
- class Last<Tok extends Token> extends WalkTokenSet<Tok> {
- public Last(Topology<Tok> cs, Walk.Cache cache) { super(cs, cache); }
- public Topology<Tok> sequence(Sequence seq) { sequence(seq.firstp()); return cs; }
- private Topology<Tok> sequence(Position p) {
- if (p==null) return null;
- Topology<Tok> ret = sequence(p.next());
- if (ret!=null) return ret;
- if (p.isLast()) return null;
- if (p.element().possiblyEpsilon(c)) return null;
- if (p.element()==null) return null;
- return walk(p.element());
- }
- }
-
- static class Follow<Tok extends Token> extends WalkTokenSet<Tok> {
- private final Element me;
- private final HashSet<Element> all;
+ static class Follow<Tok extends Input> extends WalkTokenSet<Tok> {
+ private final SequenceOrElement me;
+ private final HashSet<SequenceOrElement> all;
private boolean eof = false;
public boolean includesEof() { return eof; }
- public Follow(Topology<Tok> cs, Element me, HashSet<Element> all, Cache c) { super(cs, c); this.me = me; this.all = all; }
- public Topology<Tok> bottom(Element e) { return cs; }
- public Topology<Tok> sequence(Sequence seq) { return cs; }
- public Topology<Tok> walkAtom(Atom r) { return walk((Element)r); }
- public Topology<Tok> walk(Element e) {
+ 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> 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);
acc.add(e);
if (c != null) {
Topology<Tok> cached = (Topology<Tok>)c.follow.get(e);
if (cached != null) {
- cs.add(cached);
+ cs = cs.union(cached);
eof |= c.eof.get(e);
return cs;
}
Topology<Tok> cso = cs;
boolean eofo = eof;
- eof = false;
- cs = cso.fresh();
+ eof = c.eof.get(e) != null && c.eof.get(e).booleanValue();
+ cs = cso.empty();
- if (e instanceof Parser.Table.Top) eof = true;
- for(Element x : all) {
+ for(SequenceOrElement x : all) {
boolean matched = false;
- if (x instanceof Parser.Table.Top) walk(x); // because this symbol might not appear in any other Sequence
if (!(x instanceof Sequence)) continue;
Sequence a = (Sequence)x;
Position mp = null;
for(Position pos = a.firstp(); pos != null && !pos.isLast(); pos = pos.next()) {
- if (matched) cs.add(new First<Tok>(cs.fresh(), c).walk(pos.element()));
- if (pos.isLast()) { matched = (matched && pos.element().possiblyEpsilon(c)); continue; }
+ if (matched) cs = cs.union(c.first(pos.element(), cs.empty()));
+ if (pos.isLast()) { matched = (matched && c.possiblyEpsilon(pos.element())); continue; }
boolean good = false;
if (e instanceof Atom) {
Topology top = c.atoms.get(pos.element());
if (top==null) continue;
- if (!(top.containsAll(((Atom)e).top()))) continue;
+ if (!(top.containsAll(((Atom)e)))) continue;
} else {
- if (c.ys.get(pos.element()).contains(e)) good = true;
+ if (c.ys.contains(pos.element(),e)) good = true;
}
if (good) {
mp = pos;
if (matched) walk(a);
}
- if (e instanceof Repeat.MaximalSequence || e instanceof Repeat.Maximal)
- cs.remove(new Last<Tok>(cs.fresh(), c).walk(e));
+ if (e instanceof Sequence) {
+ Sequence s = (Sequence)e;
+ if (s.follow != null) cs = cs.intersect(s.follow.getTokenTopology());
+ }
if (c != null && e==me) {
- c.follow.put(e, cs.dup());
+ c.follow.put(e, cs);
c.eof.put(e, eof);
}
- cso.add(cs);
+ cso = cso.union(cs);
cs = cso;
eofo |= eof;
eof = eofo;
}
static class Cache {
- public final HashMap<Element,Boolean> possiblyEpsilon = new HashMap<Element,Boolean>();
- public HashMap<Element,Boolean> eof = new HashMap<Element,Boolean>();
- public HashMap<Element,Topology> follow = new HashMap<Element,Topology>();
- public HashMap<Element,HashSet<Element>> ys = new HashMap<Element,HashSet<Element>>();
- public HashMap<Element,Topology> atoms = new HashMap<Element,Topology>();
+ public final HashMap<SequenceOrElement,Boolean> possiblyEpsilon = new HashMap<SequenceOrElement,Boolean>();
+ 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);
+ }
+ final boolean possiblyEpsilon(SequenceOrElement e) {
+ Walk.Cache cache = this;
+ Boolean ret = possiblyEpsilon.get(e);
+ if (ret != null) return ret.booleanValue();
+ ret = new Walk.PossiblyEpsilon().walk(e) ? Boolean.TRUE : Boolean.FALSE;
+ possiblyEpsilon.put(e, ret);
+ return ret;
+ }
}
}
projects / sbp.git / blobdiff