X-Git-Url: http://git.megacz.com/?p=sbp.git;a=blobdiff_plain;f=src%2Fedu%2Fberkeley%2Fsbp%2Fchr%2FCharRange.java;h=78f2057d7d233935856408bf197af94ecc0098a4;hp=deea38e3a9713e5726010d83b611c676a1d08372;hb=38eb7943a4be918d46cb6517004e57ca91410ce0;hpb=aa467fd9d82ee4ab751a6ced1e4f48864f494e90

diff --git a/src/edu/berkeley/sbp/chr/CharRange.java b/src/edu/berkeley/sbp/chr/CharRange.java
index deea38e..78f2057 100644
--- a/src/edu/berkeley/sbp/chr/CharRange.java
+++ b/src/edu/berkeley/sbp/chr/CharRange.java
@@ -12,26 +12,28 @@ public class CharRange extends Atom<Character> {
 
     public CharRange(char a) { this(a,a); }
     public CharRange(char a, char b) { this(new CharTopology(a, b)); }
-    public CharRange(Topology<Character> t) { this.t = t; }
+    public CharRange(CharTopology t) { this.t = t; }
 
-    private Topology<Character> t;
+    private CharTopology t;
     public  Topology<Character> top() { return t; }
 
     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)); }
 
     public String toString() { return t.toString(); }
 
     /** returns an element which exactly matches the string given */
-    public static Element string(String s) {
-        if (s.length() == 0) return Union.epsilon;
+    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;
         final String escapified = "\""+StringUtil.escapify(s, "\"\r\n\\")+"\"";
         Element ret;
-        if (s.length() == 1) {
+        if (share && s.length() == 1) {
             ret =
                 new CharRange(s.charAt(0)) {
                     public String toString() { return escapified; } };
@@ -46,4 +48,6 @@ public class CharRange extends Atom<Character> {
         return ret;
     }
 
+    private static Union epsilon = new Union("()");
+    static { epsilon.add(Sequence.empty); }
 }