+// 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 java.lang.ref.*;
/** <font color=green>juxtaposition; zero or more adjacent Elements; can specify a rewriting</font> */
-public abstract class Sequence /*extends Element*/ implements Iterable<Element>, SequenceOrElement {
+public abstract class Sequence implements Iterable<Element>, SequenceOrElement {
protected final Element[] elements;
public Sequence and(Sequence s) { Sequence ret = dup(); ret.needs.add(s); return ret; }
/** return a new sequence identical to this one, but with a negative conjunct <tt>s</tt> */
- public Sequence not(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); 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; }
// 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;
}
class Position implements IntegerMappable {
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);
sb.append("-> ");
sb.append(follow);
}
+ for(Sequence s : needs) {
+ sb.append("& ");
+ sb.append(s);
+ }
+ for(Sequence s : hates) {
+ sb.append("&~ ");
+ sb.append(s);
+ }
return sb;
}