import java.lang.reflect.*;
import java.lang.ref.*;
-/** juxtaposition; zero or more adjacent Elements; can specify a rewriting */
+/** <font color=green>juxtaposition; zero or more adjacent Elements; can specify a rewriting</font> */
public abstract class Sequence extends Element implements Iterable<Element> {
+ protected final Element[] elements;
+
+ final HashSet<Sequence> hated = new HashSet<Sequence>();
+
+ final HashSet<Sequence> needs = new HashSet<Sequence>();
+ final HashSet<Sequence> hates = new HashSet<Sequence>();
+
+ final Position firstp;
+
+ Atom follow = null;
+
// Static Constructors //////////////////////////////////////////////////////////////////////////////
abstract Sequence _clone();
Sequence dup() {
Sequence ret = _clone();
- for(Sequence s : needs) { ret.needs.add(s); s.needed.add(ret); }
+ for(Sequence s : needs) { ret.needs.add(s); }
for(Sequence s : hates) { ret.hates.add(s); s.hated.add(ret); }
ret.follow = follow;
return ret;
}
/** the empty sequence (matches the empty string) */
- public static final Sequence empty = new Sequence.Constant.Empty();
+ static final Sequence empty = new Sequence.Constant.Empty();
+ public static Sequence empty() { return empty; }
/** after matching the sequence, do not add anything to the output tree */
public static Sequence drop(Element[] e) { return new Constant.Drop(e); }
////////////////////////////////////////////////////////////////////////////////
- public Atom follow = null;
- public final Topology follow() { return follow; }
-
- public Sequence and(Sequence s) { Sequence ret = dup(); ret.needs.add(s); s.needed.add(ret); return ret; }
+ public Sequence and(Sequence s) { Sequence ret = dup(); ret.needs.add(s); return ret; }
public Sequence not(Sequence s) { Sequence ret = dup(); ret.hates.add(s); s.hated.add(ret); return ret; }
+ public Sequence followedBy(Atom a) { Sequence ret = dup(); ret.follow = a; return ret; }
- public Iterable<Sequence> needs() { return needs; }
- public Iterable<Sequence> hates() { return hates; }
+ Iterable<Sequence> needs() { return needs; }
+ Iterable<Sequence> hates() { return hates; }
- protected final Element[] elements;
-
- final HashSet<Sequence> needed = new HashSet<Sequence>();
- final HashSet<Sequence> hated = new HashSet<Sequence>();
- final HashSet<Sequence> needs = new HashSet<Sequence>();
- final HashSet<Sequence> hates = new HashSet<Sequence>();
-
- final Position firstp;
Position firstp() { return firstp; }
public Iterator<Element> iterator() { return new ArrayIterator<Element>(elements); }
// Position //////////////////////////////////////////////////////////////////////////////
/** the imaginary position before or after an element of a sequence; corresponds to an "LR item" */
- public class Position implements IntegerMappable {
+ class Position implements IntegerMappable {
private Forest zero = null;
public Forest zero() {
Sequence _clone() { return new Singleton(elements,idx); }
}
- public static Unwrap unwrap(Element[] e, Object tag, boolean[] drops) { return new Unwrap(e, tag, drops); }
+ public static Sequence unwrap(Element[] e, Object tag, boolean[] drops) { return new Unwrap(e, tag, drops); }
static class Unwrap extends Sequence {
private boolean[] drops;
private final Object tag;
public Unwrap(Element[] e, Object tag) { super(e); this.drops = null; this.tag = tag; }
public Unwrap(Element[] e, Object tag, boolean[] drops) { super(e); this.drops = drops; this.tag = tag; }
- Sequence _clone() { return new Unwrap(elements, drops); }
+ Sequence _clone() { return new Unwrap(elements, tag, drops); }
public <T> Forest<T> postReduce(Input.Region loc, Forest<T>[] args, Position p) {
for(int i=0; i<args.length; i++) if (args[i]==null) throw new Error();
if (drops==null) return Forest.create(loc, (T)tag, args, true);
}
}
- // Repeat //////////////////////////////////////////////////////////////////////////////
-
- /** repeat zero or one times */
- public static Element maybe(Element e) { return new Repeat(e, true, false, null, null); }
- public static Element maybe(Element e, Object tag) { return new Repeat(e, true, false, null, tag); }
- /** repeat zero or more times */
- public static Element many0(Element e) { return new Repeat(e, true, true, null, null); }
- public static Element many0(Element e, Object tag) { return new Repeat(e, true, true, null, tag); }
- /** repeat zero or more times, separated by <tt>sep</tt> */
- public static Element many0(Element e, Element sep) { return new Repeat(e, true, true, sep, null); }
- public static Element many0(Element e, Element sep, Object tag) { return new Repeat(e, true, true, sep, tag); }
- /** repeat one or more times */
- public static Element many1(Element e) { return new Repeat(e, false, true, null, null); }
- public static Element many1(Element e, Object tag) { return new Repeat(e, false, true, null, tag); }
- /** repeat one or more times, separated by <tt>sep</tt> */
- public static Element many1(Element e, Element sep) { return new Repeat(e, false, true, sep, null); }
- public static Element many1(Element e, Element sep, Object tag) { return new Repeat(e, false, true, sep, tag); }
-
- /** repeat zero or more times, matching a maximal sequence of atoms */
- public static Element maximal0(Atom e) { return new Repeat.Maximal(e, true, true, null); }
- public static Element maximal0(Atom e, Object tag) { return new Repeat.Maximal(e, true, true, tag); }
- /** repeat one or more times, matching a maximal sequence of atoms */
- public static Element maximal1(Atom e) { return new Repeat.Maximal(e, false, true, null); }
- public static Element maximal1(Atom e, Object tag) { return new Repeat.Maximal(e, false, true, tag); }
- /** repeat one or more times, separated by an atom <tt>sep</tt>, matching a maximal sequence */
- public static Element maximal1(Element e, Atom sep) { return new Repeat.Maximal(e, false, true, sep, null); }
- public static Element maximal1(Element e, Atom sep, Object tag) { return new Repeat.Maximal(e, false, true, sep, tag); }
-
- public static Element repeatMaximal(Atom e, boolean zero, boolean many, Object tag) {
- return new Repeat.Maximal(e, zero, many, tag); }
- public static Element repeatMaximal(Element e, boolean zero, boolean many, Atom sep, Object tag) {
- return new Repeat.Maximal(e, zero, many, sep, tag); }
- public static Element repeat(Element e, boolean zero, boolean many, Object tag) {
- return new Repeat(e, zero, many, tag); }
- public static Element repeat(Element e, boolean zero, boolean many, Element sep, Object tag) {
- return new Repeat(e, zero, many, sep, tag); }
}