From 8d4197c069c477cb1285b047b4e4ea5ca22ad79d Mon Sep 17 00:00:00 2001
From: mike <mike>
Date: Fri, 29 Jun 2007 15:38:56 +0000
Subject: [PATCH] Support for "==" relation (TT_EQEQ)

---
 src/org/z3950/zing/cql/CQLLexer.java  |   25 ++++++++++++++++++++-----
 src/org/z3950/zing/cql/CQLParser.java |    7 ++++---
 2 files changed, 24 insertions(+), 8 deletions(-)

diff --git a/src/org/z3950/zing/cql/CQLLexer.java b/src/org/z3950/zing/cql/CQLLexer.java
index 11c99ea..01cc05d 100644
--- a/src/org/z3950/zing/cql/CQLLexer.java
+++ b/src/org/z3950/zing/cql/CQLLexer.java
@@ -1,4 +1,4 @@
-// $Id: CQLLexer.java,v 1.12 2007-06-29 12:54:05 mike Exp $
+// $Id: CQLLexer.java,v 1.13 2007-06-29 15:38:56 mike Exp $
 
 package org.z3950.zing.cql;
 import java.io.StreamTokenizer;
@@ -19,10 +19,11 @@ class CQLLexer extends StreamTokenizer {
     static int TT_LE        = 1000;	// The "<=" relation
     static int TT_GE        = 1001;	// The ">=" relation
     static int TT_NE        = 1002;	// The "<>" relation
-    static int TT_AND       = 1003;	// The "and" boolean
-    static int TT_OR        = 1004;	// The "or" boolean
-    static int TT_NOT       = 1005;	// The "not" boolean
-    static int TT_PROX      = 1006;	// The "prox" boolean
+    static int TT_EQEQ      = 1003;	// The "==" relation
+    static int TT_AND       = 1004;	// The "and" boolean
+    static int TT_OR        = 1005;	// The "or" boolean
+    static int TT_NOT       = 1006;	// The "not" boolean
+    static int TT_PROX      = 1007;	// The "prox" boolean
 
     // Support for keywords.  It would be nice to compile this linear
     // list into a Hashtable, but it's hard to store ints as hash
@@ -126,6 +127,18 @@ class CQLLexer extends StreamTokenizer {
 		ttype = '>';
 		debug("AFTER: ttype is now " + ttype + " - " + render());
 	    }
+	} else if (ttype == '=') {
+	    debug("token starts with '=' ...");
+	    underlyingNextToken();
+	    if (ttype == '=') {
+		debug("token continues with '=' - it's '=='");
+		ttype = TT_EQEQ;
+	    } else {
+		debug("next token is " + render() + " (pushed back)");
+		halfDecentPushBack();
+		ttype = '=';
+		debug("AFTER: ttype is now " + ttype + " - " + render());
+	    }
 	}
 
 	debug("done nextToken(): ttype=" + ttype + ", " +
@@ -175,6 +188,8 @@ class CQLLexer extends StreamTokenizer {
 	    return ">=";
 	} else if (token == TT_NE) {
 	    return "<>";
+	} else if (token == TT_EQEQ) {
+	    return "==";
 	}
 
 	// Check whether its associated with one of the keywords
diff --git a/src/org/z3950/zing/cql/CQLParser.java b/src/org/z3950/zing/cql/CQLParser.java
index 59d41d9..b23506c 100644
--- a/src/org/z3950/zing/cql/CQLParser.java
+++ b/src/org/z3950/zing/cql/CQLParser.java
@@ -1,4 +1,4 @@
-// $Id: CQLParser.java,v 1.35 2007-06-29 15:24:26 mike Exp $
+// $Id: CQLParser.java,v 1.36 2007-06-29 15:39:09 mike Exp $
 
 package org.z3950.zing.cql;
 import java.io.IOException;
@@ -12,7 +12,7 @@ import java.io.FileNotFoundException;
 /**
  * Compiles CQL strings into parse trees of CQLNode subtypes.
  *
- * @version	$Id: CQLParser.java,v 1.35 2007-06-29 15:24:26 mike Exp $
+ * @version	$Id: CQLParser.java,v 1.36 2007-06-29 15:39:09 mike Exp $
  * @see		<A href="http://zing.z3950.org/cql/index.html"
  *		        >http://zing.z3950.org/cql/index.html</A>
  */
@@ -203,7 +203,8 @@ public class CQLParser {
 		lexer.ttype == '=' ||
 		lexer.ttype == lexer.TT_LE ||
 		lexer.ttype == lexer.TT_GE ||
-		lexer.ttype == lexer.TT_NE);
+		lexer.ttype == lexer.TT_NE ||
+		lexer.ttype == lexer.TT_EQEQ);
     }
 
     private void match(int token)
-- 
1.7.10.4