1 package edu.berkeley.sbp.misc;
4 import java.lang.reflect.*;
5 import java.lang.ref.*;
6 import edu.berkeley.sbp.*;
7 import edu.berkeley.sbp.Token.Location;
8 import edu.berkeley.sbp.util.*;
10 public class CharRange extends Atom<Character> {
12 public CharRange(char a) { this(a,a); }
13 public CharRange(char a, char b) { this(new CharTopology(a, b)); }
14 public CharRange(Topology<Character> t) { this.t = t; }
16 private Topology<Character> t;
17 public Topology<Character> top() { return t; }
19 public static final char left = (char)9998;
20 public static final char right = (char)9999;
21 public static final Atom leftBrace = new CharRange(left,left) { public String toString() { return "{"; } };
22 public static final Atom rightBrace = new CharRange(right,right) { public String toString() { return "}"; } };
24 public static Atom set(Range.Set r) { return new CharRange(new CharTopology(r)); }
26 public String toString() { return t.toString(); }
28 /** returns an element which exactly matches the string given */
29 public static Element string(String s) {
30 if (s.length() == 0) return Union.epsilon;
31 final String escapified = "\""+StringUtil.escapify(s, "\"\r\n\\")+"\"";
33 if (s.length() == 1) {
35 new CharRange(s.charAt(0)) {
36 public String toString() { return escapified; } };
38 Union ret2 = new Union("\""+s+"\"_str", true) {
39 public String toString() { return escapified; } };
40 Element[] refs = new Element[s.length()];
41 for(int i=0; i<refs.length; i++) refs[i] = new CharRange(s.charAt(i));
42 ret2.add(Sequence.constant(refs, s, null, null));