X-Git-Url: http://git.megacz.com/?p=sbp.git;a=blobdiff_plain;f=src%2Fedu%2Fberkeley%2Fsbp%2Fchr%2FCharAtom.java;h=45c85b95a1ca94c7af6f891a2b0746d216db94d0;hp=89a45ad154ff1603eaac320f7a74eab792a11611;hb=987a3f1d9ae796bb8db1294654125b07255128a5;hpb=173e1696d10a91db6f5a919dbb2b2ed2c6e2a227

diff --git a/src/edu/berkeley/sbp/chr/CharAtom.java b/src/edu/berkeley/sbp/chr/CharAtom.java
index 89a45ad..45c85b9 100644
--- a/src/edu/berkeley/sbp/chr/CharAtom.java
+++ b/src/edu/berkeley/sbp/chr/CharAtom.java
@@ -1,3 +1,5 @@
+// Copyright 2006 all rights reserved; see LICENSE file for BSD-style license
+
 package edu.berkeley.sbp.chr;
 import java.io.*;
 import java.util.*;
@@ -21,18 +23,17 @@ public class CharAtom extends Atom<Character> {
 
     public static final char left       = (char)9998;
     public static final char right      = (char)9999;
-    public static final Atom leftBrace  = new CharAtom(left,left)   { public String toString() { return "[{]"; } };
-    public static final Atom rightBrace = new CharAtom(right,right) { public String toString() { return "[}]"; } };
-    public static final Atom braces     = new CharAtom(left,right)   { public String toString() { return "[{}]"; } };
+    public static final Atom leftBrace  = new CharAtom(left,left)   { public String toString() { return "\\{"; } };
+    public static final Atom rightBrace = new CharAtom(right,right) { public String toString() { return "\\}"; } };
+    public static final Atom braces     = new CharAtom(left,right)   { public String toString() { return "[\\{\\}]"; } };
 
     public static Atom set(Range.Set r) { return new CharAtom(new CharTopology(r)); }
-
     public String toString() { return t.toString(); }
 
     /** returns an element which exactly matches the string given */
     public static Element string(String s) { return string(s, true); }
     public static Element string(String s, boolean share) {
-        if (share && s.length() == 0) return epsilon;
+        if (share && s.length() == 0) return emptyString;
         final String escapified = "\""+StringUtil.escapify(s, "\"\r\n\\")+"\"";
         Element ret;
         if (share && s.length() == 1) {
@@ -44,18 +45,21 @@ public class CharAtom extends Atom<Character> {
                     public String toString() { return escapified; } };
             Element[] refs = new Element[s.length()];
             for(int i=0; i<refs.length; i++) refs[i] = new CharAtom(s.charAt(i));
-            ret2.add(Sequence.constant(refs, s));
+            ret2.add(Sequence.create(refs, s));
             ret = ret2;
         }
         return ret;
     }
 
-    private static Union epsilon = new Union("()");
-    static { epsilon.add(Sequence.empty); }
+    private static Union emptyString = new Union("()");
+    static {
+        // FIXME: force this to be dropped wherever used!
+        emptyString.add(Sequence.create(new Element[0], ""));
+    }
 
     public Topology<Atom<Character>>       unwrap() { return this; }
     public Topology<Atom<Character>>       empty()  { return new CharAtom(); }
-    public Topology<Character>             underlying()  { return top(); }
+    public Topology<Character>             getTokenTopology()  { return top(); }
 
     public boolean           contains(Atom<Character> v) { return top().containsAll(((CharAtom)v).top()); }
     public boolean           disjoint(Topology<Atom<Character>> t) { return top().disjoint(((CharAtom)t).top()); }