1 package edu.berkeley.sbp.meta;
2 import edu.berkeley.sbp.util.*;
3 import edu.berkeley.sbp.*;
6 import java.lang.reflect.*;
7 import java.lang.ref.*;
9 /** currently this class exports only static methods to create repetitions; there are no public instance methods or constructors */
10 public class Repeat extends Union {
12 public Repeat(final Element e, boolean zeroOkay, boolean manyOkay, Object tag) {
13 this(e, zeroOkay, manyOkay, null, false, tag); }
14 public Repeat(final Element e, boolean zeroOkay, boolean manyOkay, final Element separator, Object tag) {
15 this(e, zeroOkay, manyOkay, separator, false, tag); }
16 protected Repeat(final Element e, boolean zeroOkay, boolean manyOkay, final Element separator, boolean maximal, Object tag) {
17 this(e, zeroOkay, manyOkay, separator, maximal, tag, null); }
18 protected Repeat(final Element e, boolean zeroOkay, boolean manyOkay, final Element separator, boolean maximal, Object tag, Atom follow) {
19 super(e+(!manyOkay ? "?" : (zeroOkay ? (maximal ? "**" : "*") : (maximal ? "++" : "+")))+(separator==null?"":("/"+separator)), true);
20 if (zeroOkay && !manyOkay) {
21 add(Sequence.create().followedBy(follow));
22 add(Sequence.create(e).followedBy(follow));
26 add(Sequence.create(tag, new Element[] { }, null, false).followedBy(follow));
27 //add(new Sequence.Constant.Empty());
29 add(Sequence.create(many1(e, separator, tag)).followedBy(follow));
31 add(Sequence.create(tag, new Element[] { e }, null, false).followedBy(follow));
33 add(Sequence.create(tag, new Element[] { e, Repeat.this }, new boolean[] { false, false }, true).followedBy(follow));
35 add(Sequence.create(tag, new Element[] { e, separator, Repeat.this }, new boolean[] { false, true, false }, true).followedBy(follow));
39 public static class Maximal extends Repeat {
40 public Maximal(final Element e, boolean zeroOkay, boolean manyOkay, final Atom separator, Object tag) {
41 super(e, zeroOkay, manyOkay, separator, true, tag, (Atom)separator.complement());
42 if (zeroOkay && separator != null)
43 throw new RuntimeException("cannot create a maximal repetition of zero or more items with a separator (yet): " + this);
45 public Maximal(final Atom e, boolean zeroOkay, boolean manyOkay, Object tag) {
46 super(e, zeroOkay, manyOkay, null, true, tag, (Atom)e.complement());
50 /** repeat zero or one times */
51 public static Element maybe(Element e) { return new Repeat(e, true, false, null, null); }
52 public static Element maybe(Element e, Object tag) { return new Repeat(e, true, false, null, tag); }
53 /** repeat zero or more times */
54 public static Element many0(Element e) { return new Repeat(e, true, true, null, null); }
55 public static Element many0(Element e, Object tag) { return new Repeat(e, true, true, null, tag); }
56 /** repeat zero or more times, separated by <tt>sep</tt> */
57 public static Element many0(Element e, Element sep) { return new Repeat(e, true, true, sep, null); }
58 public static Element many0(Element e, Element sep, Object tag) { return new Repeat(e, true, true, sep, tag); }
59 /** repeat one or more times */
60 public static Element many1(Element e) { return new Repeat(e, false, true, null, null); }
61 public static Element many1(Element e, Object tag) { return new Repeat(e, false, true, null, tag); }
62 /** repeat one or more times, separated by <tt>sep</tt> */
63 public static Element many1(Element e, Element sep) { return new Repeat(e, false, true, sep, null); }
64 public static Element many1(Element e, Element sep, Object tag) { return new Repeat(e, false, true, sep, tag); }
66 /** repeat zero or more times, matching a maximal sequence of atoms */
67 public static Element maximal0(Atom e) { return new Repeat.Maximal(e, true, true, null); }
68 public static Element maximal0(Atom e, Object tag) { return new Repeat.Maximal(e, true, true, tag); }
69 /** repeat one or more times, matching a maximal sequence of atoms */
70 public static Element maximal1(Atom e) { return new Repeat.Maximal(e, false, true, null); }
71 public static Element maximal1(Atom e, Object tag) { return new Repeat.Maximal(e, false, true, tag); }
72 /** repeat one or more times, separated by an atom <tt>sep</tt>, matching a maximal sequence */
73 public static Element maximal1(Element e, Atom sep) { return new Repeat.Maximal(e, false, true, sep, null); }
74 public static Element maximal1(Element e, Atom sep, Object tag) { return new Repeat.Maximal(e, false, true, sep, tag); }
76 public static Element repeatMaximal(Atom e, boolean zero, boolean many, Object tag) {
77 return new Repeat.Maximal(e, zero, many, tag); }
78 public static Element repeatMaximal(Element e, boolean zero, boolean many, Atom sep, Object tag) {
79 return new Repeat.Maximal(e, zero, many, sep, tag); }
80 public static Element repeat(Element e, boolean zero, boolean many, Object tag) {
81 return new Repeat(e, zero, many, tag); }
82 public static Element repeat(Element e, boolean zero, boolean many, Element sep, Object tag) {
83 return new Repeat(e, zero, many, sep, tag); }