allow lifts on any position

[sbp.git] / src / edu / berkeley / sbp / chr / CharAtom.java

diff --git a/src/edu/berkeley/sbp/chr/CharAtom.java b/src/edu/berkeley/sbp/chr/CharAtom.java
index c0df627..f0b7a9e 100644 (file)
--- 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.*;
@@ -10,27 +12,28 @@ import edu.berkeley.sbp.Input.Location;
 
 public class CharAtom extends Atom<Character> {
 
+    public CharAtom() { this(new CharTopology()); }
     public CharAtom(char a) { this(a,a); }
     public CharAtom(char a, char b) { this(new CharTopology(a, b)); }
     public CharAtom(CharTopology t) { this.t = t; }
+    public CharAtom(Topology<Character> t) { this(t instanceof CharTopology ? (CharTopology)t : new CharTopology(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 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) {
@@ -42,12 +45,32 @@ 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(s, refs));
             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>             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()); }
+    public boolean           containsAll(Topology<Atom<Character>> t) { return top().containsAll(((CharAtom)t).top()); }
+
+    public Topology<Atom<Character>>       complement() { return new CharAtom(top().complement()); }
+    public Topology<Atom<Character>>       intersect(Topology<Atom<Character>> t) { return new CharAtom(top().intersect(((CharAtom)t).top())); }
+    public Topology<Atom<Character>>       minus(Topology<Atom<Character>> t) { return new CharAtom(top().minus(((CharAtom)t).top())); }
+    public Topology<Atom<Character>>       union(Topology<Atom<Character>> t) { return new CharAtom(top().union(((CharAtom)t).top())); }
+
+    public int     hashCode() { return top().hashCode(); }
+    public boolean equals(Object o) { return o != null && (o instanceof CharAtom) && ((CharAtom)o).top().equals(top()); }
+
 }