-// $Id: CQLNode.java,v 1.3 2002-10-25 16:04:44 mike Exp $
+// $Id: CQLNode.java,v 1.7 2002-10-30 09:19:26 mike Exp $
package org.z3950.zing.cql;
/**
- * Represents a node in a CQL parse-tree ...
+ * Represents a node in a CQL parse-tree.
* ###
*
- * @version $Id: CQLNode.java,v 1.3 2002-10-25 16:04:44 mike Exp $
+ * @version $Id: CQLNode.java,v 1.7 2002-10-30 09:19:26 mike Exp $
*/
public abstract class CQLNode {
abstract String toXCQL(int level);
return x;
}
+ // XML Quote --
+ // s/&/&/g;
+ // s/</</g;
+ // s/>/>/g;
+ // This is hideously inefficient, but I just don't see a better
+ // way using the standard JAVA library.
+ //
+ protected String xq(String str) {
+ str = replace(str, "&", "&");
+ str = replace(str, "<", "<");
+ str = replace(str, ">", ">");
+ return str;
+ }
+
+ // I can't _believe_ I have to write this by hand in 2002 ...
+ protected static String replace(String str, String from, String to) {
+ StringBuffer sb = new StringBuffer();
+ int ix; // index of next `from'
+ int offset = 0; // index of previous `from' + length(from)
+
+ while ((ix = str.indexOf(from, offset)) != -1) {
+ sb.append(str.substring(offset, ix));
+ sb.append(to);
+ offset = ix + from.length();
+ }
+
+ // End of string: append last bit and we're done
+ sb.append(str.substring(offset));
+ return sb.toString();
+ }
+
// Test harness
public static void main (String[] args) {
CQLNode n1 = new CQLTermNode("dc.author", "=", "kernighan");
CQLNode n2 = new CQLTermNode("dc.title", "all", "elements style");
CQLNode root = new CQLAndNode(n1, n2);
- System.out.println(root.toXCQL(3));
+ System.out.println(root.toXCQL(0));
}
}