X-Git-Url: http://git.megacz.com/?p=sbp.git;a=blobdiff_plain;f=src%2Fedu%2Fberkeley%2Fsbp%2Fmeta%2FRepeat.java;fp=src%2Fedu%2Fberkeley%2Fsbp%2Fmeta%2FRepeat.java;h=f21e8209b6b58d06592caae54f00ca1d38b71571;hp=0000000000000000000000000000000000000000;hb=e6be1f03f79b16cd410991d7e64cfa7beab6de59;hpb=b8a597c8d1a29afc24f9b89f726d5b1a9b9aeec1

diff --git a/src/edu/berkeley/sbp/meta/Repeat.java b/src/edu/berkeley/sbp/meta/Repeat.java
new file mode 100644
index 0000000..f21e820
--- /dev/null
+++ b/src/edu/berkeley/sbp/meta/Repeat.java
@@ -0,0 +1,84 @@
+package edu.berkeley.sbp.meta;
+import edu.berkeley.sbp.util.*;
+import edu.berkeley.sbp.*;
+import java.io.*;
+import java.util.*;
+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 {
+
+    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) {
+        this(e, zeroOkay, manyOkay, separator, maximal, tag, null); }
+    protected Repeat(final Element e, boolean zeroOkay, boolean manyOkay, final Element separator, boolean maximal, Object tag, Atom follow) {
+        super(e+(!manyOkay ? "?" : (zeroOkay ? (maximal ? "**" : "*") : (maximal ? "++" : "+")))+(separator==null?"":("/"+separator)), true);
+        if (zeroOkay && !manyOkay) {
+            add(Sequence.empty().followedBy(follow));
+            add(Sequence.singleton(e).followedBy(follow));
+            return;
+        }
+        if (zeroOkay) {
+            add(Sequence.rewritingSequence(tag, new Element[] { }, null).followedBy(follow));
+            //add(new Sequence.Constant.Empty());
+            // FUGLY
+            add(Sequence.singleton(many1(e, separator, tag)).followedBy(follow));
+        } else {
+            add(Sequence.rewritingSequence(tag, new Element[] { e }, null).followedBy(follow));
+            if (separator==null)
+                add(Sequence.unwrap(new Element[] { e,                 Repeat.this }, tag, new boolean[] { false, false }).followedBy(follow));
+            else
+                add(Sequence.unwrap(new Element[] { e, separator,      Repeat.this }, tag, new boolean[] { false, true, false }).followedBy(follow));
+        }
+    }
+
+    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, (Atom)separator.complement());
+            if (zeroOkay && separator != null)
+                throw new RuntimeException("cannot create a maximal repetition of zero or more items with a separator (yet): " + this);
+        }
+        public Maximal(final Atom e, boolean zeroOkay, boolean manyOkay, Object tag) {
+            super(e, zeroOkay, manyOkay, null, true, tag, (Atom)e.complement());
+        }
+    }
+
+    /** 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); }
+}