1 package edu.berkeley.sbp;
2 import edu.berkeley.sbp.util.*;
3 import edu.berkeley.sbp.*;
4 import edu.berkeley.sbp.*;
7 import java.lang.reflect.*;
8 import java.lang.ref.*;
10 /** currently this class exports only static methods to create repetitions; there are no public instance methods or constructors */
11 public class Repeat extends Union {
13 /** repeat zero or one times */
14 public static Repeat maybe(Element e) { return new Repeat(e, true, false); }
15 /** repeat zero or more times */
16 public static Repeat many0(Element e) { return new Repeat(e, true, true); }
17 /** repeat zero or more times, separated by <tt>sep</tt> */
18 public static Repeat many0(Element e, Element sep) { return new Repeat(e, true, true, sep); }
19 /** repeat one or more times */
20 public static Repeat many1(Element e) { return new Repeat(e, false, true); }
21 /** repeat one or more times, separated by <tt>sep</tt> */
22 public static Repeat many1(Element e, Element sep) { return new Repeat(e, false, true, sep); }
23 public static Maximal maximal(Element e) { return new Maximal(e); }
25 // Instance //////////////////////////////////////////////////////////////////////////////
27 final boolean zeroOkay, manyOkay;
29 final Element separator;
31 Repeat(final Element e, boolean zeroOkay, boolean manyOkay) { this(e, zeroOkay, manyOkay, null); }
32 Repeat(final Element e, boolean zeroOkay, boolean manyOkay, Element separator) {
33 super(e+(!manyOkay ? "?" : (zeroOkay ? "*" : "+"))+(separator==null?"":("/"+separator.toString())), true);
35 this.zeroOkay = zeroOkay;
36 this.manyOkay = manyOkay;
37 this.separator = separator;
39 add(new Sequence.Constant.Empty());
40 if (manyOkay) add(new Sequence.Singleton(many1(e, separator), null, null));
41 else add(new Sequence.Singleton(e, null, null));
43 add(new Sequence.RewritingSequence(null, new Element[] { e }, null, null));
44 if (this.separator==null) {
45 add(new Sequence.Unwrap(new Element[] { e, Repeat.this }, null, null));
47 add(new Sequence.Unwrap(new Element[] { e, this.separator, Repeat.this }, new boolean[] { false, true, false }, null, null));
52 static class MaximalSequence extends Sequence.Singleton {
53 private final Element e;
54 public String toString() { return e+"@";}
55 public MaximalSequence(Element e) { super(e, null, null); this.e = e; }
57 static class Maximal extends Union {
58 public Maximal(final Element e) {
60 add(new MaximalSequence(e));