X-Git-Url: http://git.megacz.com/?p=sbp.git;a=blobdiff_plain;f=src%2Fedu%2Fberkeley%2Fsbp%2Fchr%2FCharRange.java;h=78f2057d7d233935856408bf197af94ecc0098a4;hp=89525363ed07114eed1a20a6da68a4fbe1ad3873;hb=38eb7943a4be918d46cb6517004e57ca91410ce0;hpb=e5cfb136bf7fd1352eff1bd87a458aa4ff748537

diff --git a/src/edu/berkeley/sbp/chr/CharRange.java b/src/edu/berkeley/sbp/chr/CharRange.java
index 8952536..78f2057 100644
--- a/src/edu/berkeley/sbp/chr/CharRange.java
+++ b/src/edu/berkeley/sbp/chr/CharRange.java
@@ -19,8 +19,9 @@ public class CharRange extends Atom<Character> {
 
     public static final char left       = (char)9998;
     public static final char right      = (char)9999;
-    public static final Atom leftBrace  = new CharRange(left,left)   { public String toString() { return "{"; } };
-    public static final Atom rightBrace = new CharRange(right,right) { public String toString() { return "}"; } };
+    public static final Atom leftBrace  = new CharRange(left,left)   { public String toString() { return "[{]"; } };
+    public static final Atom rightBrace = new CharRange(right,right) { public String toString() { return "[}]"; } };
+    public static final Atom braces     = new CharRange(left,right)   { public String toString() { return "[{}]"; } };
 
     public static Atom set(Range.Set r) { return new CharRange(new CharTopology(r)); }
 
@@ -29,7 +30,7 @@ public class CharRange extends Atom<Character> {
     /** 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 Union.epsilon;
+        if (share && s.length() == 0) return epsilon;
         final String escapified = "\""+StringUtil.escapify(s, "\"\r\n\\")+"\"";
         Element ret;
         if (share && s.length() == 1) {
@@ -47,4 +48,6 @@ public class CharRange extends Atom<Character> {
         return ret;
     }
 
+    private static Union epsilon = new Union("()");
+    static { epsilon.add(Sequence.empty); }
 }