checkpoint

[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
new file mode 100644 (file)
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+++ b/src/edu/berkeley/sbp/chr/CharAtom.java
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+package edu.berkeley.sbp.chr;
+import java.io.*;
+import java.util.*;
+import java.lang.reflect.*;
+import java.lang.ref.*;
+import edu.berkeley.sbp.*;
+import edu.berkeley.sbp.util.*;
+import edu.berkeley.sbp.misc.*;
+import edu.berkeley.sbp.Input.Location;
+
+public class CharAtom extends Atom<Character> {
+
+    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; }
+
+    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 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;
+        final String escapified = "\""+StringUtil.escapify(s, "\"\r\n\\")+"\"";
+        Element ret;
+        if (share && s.length() == 1) {
+            ret =
+                new CharAtom(s.charAt(0)) {
+                    public String toString() { return escapified; } };
+        } else {
+            Union ret2 = new Union("\""+s+"\"_str", true) {
+                    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));
+            ret = ret2;
+        }
+        return ret;
+    }
+
+    private static Union epsilon = new Union("()");
+    static { epsilon.add(Sequence.empty); }
+}