+// 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.*;
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) {
}
}
- 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) {
+ 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);
}
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);
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 = cs.union(r); return cs; }
+ public Topology<Tok> bottom(SequenceOrElement e) { return cs; }
+ public Topology<Tok> walkAtom(Atom r) { cs = cs.union(r.getTokenTopology()); return cs; }
}
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;
}
static class Follow<Tok extends Input> extends WalkTokenSet<Tok> {
- private final Element me;
- private final HashSet<Element> all;
+ 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);
eof = c.eof.get(e) != null && c.eof.get(e).booleanValue();
cs = cso.empty();
- for(Element x : all) {
+ for(SequenceOrElement x : all) {
boolean matched = false;
if (!(x instanceof Sequence)) continue;
Sequence a = (Sequence)x;
if (e instanceof Sequence) {
Sequence s = (Sequence)e;
- if (s.follow() != null) cs = cs.intersect(s.follow());
+ if (s.follow != null) cs = cs.intersect(s.follow.getTokenTopology());
}
if (c != null && e==me) {
}
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 HashMapBag<Element,Element> ys = new HashMapBag<Element,Element>();
- public HashMap<Element,Topology> atoms = new HashMap<Element,Topology>();
- public <Tok extends Input> Topology<Tok> first(Element e, Topology<Tok> empty) {
+ 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 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(Element e) {
+ final boolean possiblyEpsilon(SequenceOrElement e) {
Walk.Cache cache = this;
Boolean ret = possiblyEpsilon.get(e);
if (ret != null) return ret.booleanValue();