X-Git-Url: http://git.megacz.com/?p=sbp.git;a=blobdiff_plain;f=src%2Fedu%2Fberkeley%2Fsbp%2FRepeat.java;h=b7e7e39703f54e35c426427f6e804f076cc18648;hp=35f34775726f3ddb151fbc72ff670769aa2999d5;hb=6ae224025882c9929e2e4e9e8461decbf3b9cae4;hpb=77d1e5fd29be1ca529e71a4c011f5edea61588e8

diff --git a/src/edu/berkeley/sbp/Repeat.java b/src/edu/berkeley/sbp/Repeat.java
index 35f3477..b7e7e39 100644
--- a/src/edu/berkeley/sbp/Repeat.java
+++ b/src/edu/berkeley/sbp/Repeat.java
@@ -8,56 +8,48 @@ 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 <tt>sep</tt> */
-    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 <tt>sep</tt> */
-    public  static Repeat many1(Element e, Element sep) { return new Repeat(e, false, true, sep); }
-    public  static Maximal maximal(Element e)           { return new Maximal(e); }
-
-    // Instance //////////////////////////////////////////////////////////////////////////////
-    
-    final boolean zeroOkay, manyOkay;
-    final Element e;
-    final Element separator;
-
-    Repeat(final Element e, boolean zeroOkay, boolean manyOkay) { this(e, zeroOkay, manyOkay, null); }
-    Repeat(final Element e, boolean zeroOkay, boolean manyOkay, Element separator) {
-        super(e+(!manyOkay ? "?" : (zeroOkay ? "*" : "+"))+(separator==null?"":("/"+separator.toString())), true);
-        this.e = e;
-        this.zeroOkay = zeroOkay;
-        this.manyOkay = manyOkay;
-        this.separator = separator;
+    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 (zeroOkay) {
             add(new Sequence.Constant.Empty());
-            if (manyOkay) add(new Sequence.Singleton(many1(e, separator), null, null));
-            else          add(new Sequence.Singleton(e, null, null));
+            if (manyOkay) add(new Sequence.Singleton(Sequence.many1(e, separator)));
+            else          add(new Sequence.Singleton(e));
         } else {
-            add(new Sequence.RewritingSequence(null, new Element[] { e }, null, null));
-            if (this.separator==null) {
-                add(new Sequence.Unwrap(new Element[] { e,                 Repeat.this }, null, null));
-            } else {
-                add(new Sequence.Unwrap(new Element[] { e, this.separator, Repeat.this }, new boolean[] { false, true, false }, null, null));
-            }
+            add(new Sequence.RewritingSequence(tag, new Element[] { e }, null));
+            if (separator==null)
+                add(new Sequence.Unwrap(new Element[] { e,                 Repeat.this }, tag));
+            else
+                add(new Sequence.Unwrap(new Element[] { e, separator,      Repeat.this }, tag, new boolean[] { false, true, false }));
         }
     }
 
-    static class MaximalSequence extends Sequence.Singleton {
-        private final Element e;
-        public String toString() { return e+"@";}
-        public MaximalSequence(Element e) { super(e, null, null); this.e = e; }
-    }
-    static class Maximal extends Union {
-        public Maximal(final Element e) {
-            super(e+"+", true);
-            add(new MaximalSequence(e));
+    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 = new Invert(separator);
+        }
+        public Maximal(final Atom e, boolean zeroOkay, boolean manyOkay, Object tag) {
+            super(e, zeroOkay, manyOkay, null, true, tag);
+            for(Sequence s : this)
+                s.follow = new Invert(e);
         }
     }
+
+
+    /** an atom which tracks the inverse of some other atom */
+    private static class Invert<T extends Input> extends Atom<T> {
+        private final Atom<T> a;
+        public Invert(Atom<T> a) { this.a = a; }
+        public Topology<T> top() { return a.complement(); }
+        public String toString() { return "~"+a; }
+    }
 }