X-Git-Url: http://git.megacz.com/?p=sbp.git;a=blobdiff_plain;f=src%2Fedu%2Fberkeley%2Fsbp%2FRepeat.java;h=037e67d58b06571328e674d05eb0cbe2cd8fbacb;hp=9b6d6bb9783d031426a1006aae40533f1b940045;hb=b8a597c8d1a29afc24f9b89f726d5b1a9b9aeec1;hpb=1a79f2232401c95fb0a6a0c2bddf78d4c82e612c diff --git a/src/edu/berkeley/sbp/Repeat.java b/src/edu/berkeley/sbp/Repeat.java index 9b6d6bb..037e67d 100644 --- a/src/edu/berkeley/sbp/Repeat.java +++ b/src/edu/berkeley/sbp/Repeat.java @@ -8,43 +8,46 @@ import java.lang.reflect.*; import java.lang.ref.*; /** currently this class exports only static methods to create repetitions; there are no public instance methods or constructors */ -public class Repeat extends Union { +class Repeat extends Union { - /** repeat zero or one times */ - public static Repeat maybe(Element e) { return new Repeat(e, true, false); } - /** repeat zero or more times */ - public static Repeat many0(Element e) { return new Repeat(e, true, true); } - /** repeat zero or more times, separated by sep */ - public static Repeat many0(Element e, Element sep) { return new Repeat(e, true, true, sep); } - /** repeat one or more times */ - public static Repeat many1(Element e) { return new Repeat(e, false, true); } - /** repeat one or more times, separated by sep */ - public static Repeat many1(Element e, Element sep) { return new Repeat(e, false, true, sep); } - - /** repeat zero or more times, matching a maximal sequence of atoms */ - public static Repeat maximal0(Element e) { return new Repeat(e, true, true, null, true); } - /** repeat one or more times, matching a maximal sequence of atoms */ - public static Repeat maximal1(Element e) { return new Repeat(e, false, true, null, true); } - /** repeat one or more times, separated by an atom sep, matching a maximal sequence */ - public static Repeat maximal1(Element e, Element sep) { return new Repeat(e, false, true, sep, true); } - - private Repeat(final Element e, boolean zeroOkay, boolean manyOkay) { this(e, zeroOkay, manyOkay, null); } - private Repeat(final Element e, boolean zeroOkay, boolean manyOkay, Element separator) { this(e, zeroOkay, manyOkay, separator, false); } - private Repeat(final Element e, boolean zeroOkay, boolean manyOkay, final Element separator, boolean maximal) { + public Repeat(final Element e, boolean zeroOkay, boolean manyOkay, Object tag) { + this(e, zeroOkay, manyOkay, null, false, tag); } + public Repeat(final Element e, boolean zeroOkay, boolean manyOkay, final Element separator, Object tag) { + this(e, zeroOkay, manyOkay, separator, false, tag); } + protected Repeat(final Element e, boolean zeroOkay, boolean manyOkay, final Element separator, boolean maximal, Object tag) { super(e+(!manyOkay ? "?" : (zeroOkay ? (maximal ? "**" : "*") : (maximal ? "++" : "+")))+(separator==null?"":("/"+separator)), true); - if (maximal && zeroOkay && separator != null) - throw new RuntimeException("cannot create a maximal repetition of zero or more items with a separator (yet): " + this); - if (zeroOkay) { + if (zeroOkay && !manyOkay) { add(new Sequence.Constant.Empty()); - if (manyOkay) add(new Sequence.Singleton(many1(e, separator), null, null)); - else add(new Sequence.Singleton(e, null, null)); + add(new Sequence.Singleton(e)); + return; + } + if (zeroOkay) { + add(new Sequence.RewritingSequence(tag, new Element[] { }, null)); + //add(new Sequence.Constant.Empty()); + // FUGLY + add(new Sequence.Singleton(Sequence.many1(e, separator, tag))); } else { - add(new Sequence.RewritingSequence(null, new Element[] { e }, null, null)); + add(new Sequence.RewritingSequence(tag, new Element[] { e }, null)); if (separator==null) - add(new Sequence.Unwrap(new Element[] { e, Repeat.this }, null, null)); + add(new Sequence.Unwrap(new Element[] { e, Repeat.this }, tag)); else - add(new Sequence.Unwrap(new Element[] { e, separator, Repeat.this }, new boolean[] { false, true, false }, null, null)); + add(new Sequence.Unwrap(new Element[] { e, separator, Repeat.this }, tag, new boolean[] { false, true, false })); } - if (maximal) for(Sequence s : this) s.noFollow = separator==null ? e : separator; } + + public static class Maximal extends Repeat { + public Maximal(final Element e, boolean zeroOkay, boolean manyOkay, final Atom separator, Object tag) { + super(e, zeroOkay, manyOkay, separator, true, tag); + if (zeroOkay && separator != null) + throw new RuntimeException("cannot create a maximal repetition of zero or more items with a separator (yet): " + this); + for(Sequence s : this) + s.follow = (Atom)separator.complement(); + } + public Maximal(final Atom e, boolean zeroOkay, boolean manyOkay, Object tag) { + super(e, zeroOkay, manyOkay, null, true, tag); + for(Sequence s : this) + s.follow = (Atom)e.complement(); + } + } + }