1 files changed, 165 insertions, 0 deletions
diff --git a/velocity-engine-core/src/main/java/org/apache/velocity/runtime/parser/node/ASTMathNode.java b/velocity-engine-core/src/main/java/org/apache/velocity/runtime/parser/node/ASTMathNode.java
new file mode 100755
index 00000000..e298bc0f
--- /dev/null
+++ b/velocity-engine-core/src/main/java/org/apache/velocity/runtime/parser/node/ASTMathNode.java
@@ -0,0 +1,165 @@
+package org.apache.velocity.runtime.parser.node;
+
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import org.apache.velocity.context.InternalContextAdapter;
+import org.apache.velocity.exception.MathException;
+import org.apache.velocity.exception.MethodInvocationException;
+import org.apache.velocity.exception.TemplateInitException;
+import org.apache.velocity.runtime.RuntimeConstants;
+import org.apache.velocity.runtime.parser.Parser;
+import org.apache.velocity.util.DuckType;
+
+/**
+ * Helps handle math<br><br>
+ *
+ * Please look at the Parser.jjt file which is
+ * what controls the generation of this class.
+ *
+ * @author <a href="mailto:wglass@forio.com">Will Glass-Husain</a>
+ * @author <a href="mailto:pero@antaramusic.de">Peter Romianowski</a>
+ * @author <a href="mailto:jvanzyl@apache.org">Jason van Zyl</a>
+ * @author <a href="mailto:geirm@optonline.net">Geir Magnusson Jr.</a>
+ * @author Nathan Bubna
+ * @version $Id: ASTMathNode.java 517553 2007-03-13 06:09:58Z wglass $
+ */
+public abstract class ASTMathNode extends ASTBinaryOperator
+{
+    protected boolean strictMode = false;
+
+    public ASTMathNode(int id)
+    {
+        super(id);
+    }
+
+    public ASTMathNode(Parser p, int id)
+    {
+        super(p, id);
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public Object init(InternalContextAdapter context, Object data) throws TemplateInitException
+    {
+        super.init(context, data);
+        strictMode = rsvc.getBoolean(RuntimeConstants.STRICT_MATH, false);
+        cleanupParserAndTokens();
+        return data;
+    }
+
+    /**
+     * {@inheritDoc}
+     */
+    @Override
+    public Object jjtAccept(ParserVisitor visitor, Object data)
+    {
+        return visitor.visit(this, data);
+    }
+
+    /**
+     * gets the two args and performs the operation on them
+     *
+     * @param context
+     * @return result or null
+     * @throws MethodInvocationException
+     */
+    @Override
+    public Object value(InternalContextAdapter context) throws MethodInvocationException
+    {
+        Object left = jjtGetChild(0).value(context);
+        Object right = jjtGetChild(1).value(context);
+
+        /*
+         * should we do anything special here?
+         */
+        Object special = handleSpecial(left, right, context);
+        if (special != null)
+        {
+            return special;
+        }
+
+        // coerce to Number type, if possible
+        try
+        {
+            left = DuckType.asNumber(left);
+        }
+        catch (NumberFormatException nfe) {}
+        try
+        {
+            right = DuckType.asNumber(right);
+        }
+        catch (NumberFormatException nfe) {}
+
+        /*
+         * if not a Number, not much we can do
+         */
+        if (!(left instanceof Number) || !(right instanceof Number))
+        {
+            boolean wrongright = (left instanceof Number);
+            boolean wrongtype = wrongright ? right != null : left != null;
+            String msg = (wrongright ? "Right" : "Left")
+                        + " side of math operation ("
+                        + jjtGetChild(wrongright ? 1 : 0).literal() + ") "
+                        + (wrongtype ? "is not a Number. " : "has a null value. ")
+                        + getLocation(context);
+            if (strictMode)
+            {
+                log.error(msg);
+                throw new MathException(msg, rsvc.getLogContext().getStackTrace());
+            }
+            else
+            {
+                log.debug(msg);
+                return null;
+            }
+        }
+
+        return perform((Number)left, (Number)right, context);
+    }
+
+    /**
+     * Extension hook to allow special behavior by subclasses
+     * If this method returns a non-null value, that is returned,
+     * rather than the result of the math operation.
+     * @param left
+     * @param right
+     * @param context
+     * @return special value
+     * @see ASTAddNode#handleSpecial
+     */
+    protected Object handleSpecial(Object left, Object right, InternalContextAdapter context)
+    {
+        // do nothing, this is an extension hook
+        return null;
+    }
+
+    /**
+     * Performs the math operation represented by this node.
+     * @param left
+     * @param right
+     * @param context
+     * @return computed value
+     * @see ASTAddNode#perform(Number, Number, InternalContextAdapter)
+     */
+    public abstract Number perform(Number left, Number right, InternalContextAdapter context);
+
+}