+// 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.*;
protected final Element[] elements;
- final HashSet<Sequence> hated = new HashSet<Sequence>();
+ public boolean needed_or_hated = false;
+
+ public HashMap<Sequence,Boolean> canNeed = new HashMap<Sequence,Boolean>();
+ public HashMap<Sequence,Boolean> canKill = new HashMap<Sequence,Boolean>();
+
+ final HashSet<Sequence> hated = new HashSet<Sequence>();
final HashSet<Sequence> needs = new HashSet<Sequence>();
final HashSet<Sequence> hates = new HashSet<Sequence>();
////////////////////////////////////////////////////////////////////////////////
/** return a new sequence identical to this one, but with a positive conjunct <tt>s</tt> */
- public Sequence and(Sequence s) { Sequence ret = dup(); ret.needs.add(s); return ret; }
+ public Sequence and(Sequence s) { Sequence ret = dup(); ret.needs.add(s); s.needed_or_hated=true; return ret; }
/** return a new sequence identical to this one, but with a negative conjunct <tt>s</tt> */
- public Sequence andnot(Sequence s) { Sequence ret = dup(); ret.hates.add(s); s.hated.add(ret); return ret; }
+ public Sequence andnot(Sequence s) { Sequence ret = dup(); ret.hates.add(s); s.hated.add(ret); s.needed_or_hated=true; return ret; }
/** return a new sequence identical to this one, but with a follow-set restricted to <tt>a</tt> */
public Sequence followedBy(Atom a) { Sequence ret = dup(); ret.follow = a; return ret; }
+ boolean hatesAny(Iterable<Sequence> it) {
+ if (hates.isEmpty()) return false;
+ for(Sequence s : it) if (hates.contains(s)) return true;
+ return false;
+ }
+
Iterable<Sequence> needs() { return needs; }
Iterable<Sequence> hates() { return hates; }
// DO NOT MESS WITH THE FOLLOWING LINE!!!
private Forest.Many epsilonForm = null;
- Forest epsilonForm() {
+ Forest epsilonForm(Input.Region loc) {
if (epsilonForm!=null) return epsilonForm;
epsilonForm = new Forest.Many();
- epsilonForm.merge(firstp().rewrite(null, false));
+ epsilonForm.merge(firstp().rewrite(loc, false));
return epsilonForm;
}
/** the imaginary position before or after an element of a sequence; corresponds to an "LR item" */
class Position implements IntegerMappable {
+ public int ord = -1;
+ public int compareTo(Position p, Walk.Cache cache) {
+ Position position = this;
+ Position rposition = p;
+ int ret = 0;
+ if (Reduction.canKill(cache, position, rposition) &&
+ Reduction.canKill(cache, rposition, position)) throw new Error();
+ if (Reduction.canKill(cache, position, rposition)) ret = 1;
+ else if (Reduction.canKill(cache, rposition, position)) ret = -1;
+ if (Reduction.canNeed(cache, position, rposition)) ret = 1;
+ else if (Reduction.canNeed(cache, rposition, position)) ret = -1;
+ return ret;
+ }
+
private Forest zero = null;
- public Forest zero() {
+ public Forest zero(Input.Region reg) {
if (zero != null) return zero;
if (pos > 0) throw new Error();
- return zero = rewrite(null);
+ return zero = rewrite(reg);
}
final <T> Forest<T> rewrite(Input.Region loc) { return rewrite(loc, true); }
private final <T> Forest<T> rewrite(Input.Region loc, boolean epsilonCheck) {
- if (epsilonCheck && this==firstp()) return epsilonForm();
+ if (epsilonCheck && this==firstp()) return epsilonForm(loc);
for(int i=0; i<pos; i++) if (holder[i]==null) throw new Error("realbad " + i);
for(int i=pos; i<elements.length; i++) {
- if (holder[i]==null) holder[i] = elements[i].epsilonForm();
+ if (holder[i]==null) holder[i] = elements[i].epsilonForm(loc);
if (holder[i]==null) throw new Error("bad " + i);
}
Forest<T> ret = Sequence.this.postReduce(loc, holder, this);