Merge pull request #728 from jmcastagnetto/master

Implements Xor operation

.gitignore

@@ -18,4 +18,5 @@ broker/core/module/MOD-INF/classes/
 broker/core/WEB-INF/lib/
 broker/core/data/
 broker/core/test-output/
+tmp/
 /test-output

main/src/com/google/refine/expr/functions/booleans/Xor.java

@@ -0,0 +1,65 @@
+/*
+Copyright (c) 2013, Jesus M. Castagnetto
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+- Redistributions of source code must retain the above copyright notice, this
+  list of conditions and the following disclaimer.
+- Redistributions in binary form must reproduce the above copyright notice,
+  this list of conditions and the following disclaimer in the documentation
+  and/or other materials provided with the distribution.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+package com.google.refine.expr.functions.booleans;
+
+import java.util.Properties;
+
+import org.json.JSONException;
+import org.json.JSONWriter;
+
+import com.google.refine.expr.EvalError;
+import com.google.refine.grel.ControlFunctionRegistry;
+import com.google.refine.grel.Function;
+
+public class Xor implements Function {
+
+    /* naive implementation of the XOR operation */
+    @Override
+    public Object call(Properties bindings, Object[] args) {
+        if (args.length == 2 && 
+                args[0] != null && args[0] instanceof Boolean && 
+                args[1] != null && args[1] instanceof Boolean) {
+            boolean o1 = ((Boolean) args[0]).booleanValue();
+            boolean o2 = ((Boolean) args[1]).booleanValue();
+            return o1 != o2;
+        }
+        return new EvalError(ControlFunctionRegistry.getFunctionName(this) + " expects 2 booleans");
+    }
+
+    @Override
+    public void write(JSONWriter writer, Properties options)
+            throws JSONException {
+
+        writer.object();
+        writer.key("description");
+        writer.value("XORs two boolean values");
+        writer.key("params");
+        writer.value("boolean a, boolean b");
+        writer.key("returns");
+        writer.value("boolean");
+        writer.endObject();
+    }
+}

main/src/com/google/refine/grel/ControlFunctionRegistry.java

@@ -56,6 +56,7 @@ import com.google.refine.expr.functions.arrays.Uniques;
 import com.google.refine.expr.functions.booleans.And;
 import com.google.refine.expr.functions.booleans.Not;
 import com.google.refine.expr.functions.booleans.Or;
+import com.google.refine.expr.functions.booleans.Xor;
 import com.google.refine.expr.functions.date.DatePart;
 import com.google.refine.expr.functions.date.Inc;
 import com.google.refine.expr.functions.date.Now;
@@ -284,6 +285,7 @@ public class ControlFunctionRegistry {
         registerFunction("and", new And());
         registerFunction("or", new Or());
         registerFunction("not", new Not());
+        registerFunction("xor", new Xor());
 
         registerFunction("cross", new Cross());