svn commit: r587002 - /commons/proper/jexl/branches/2.0/src/java/org/apache/commons/jexl/Interpreter.java

[di...@apache.org]

Author: dion
Date: Sun Oct 21 23:04:52 2007
New Revision: 587002

URL: http://svn.apache.org/viewvc?rev=587002&view=rev
Log:
Add start of interpreter

Added:
    commons/proper/jexl/branches/2.0/src/java/org/apache/commons/jexl/Interpreter.java

Added: commons/proper/jexl/branches/2.0/src/java/org/apache/commons/jexl/Interpreter.java
URL: http://svn.apache.org/viewvc/commons/proper/jexl/branches/2.0/src/java/org/apache/commons/jexl/Interpreter.java?rev=587002&view=auto
==============================================================================
--- commons/proper/jexl/branches/2.0/src/java/org/apache/commons/jexl/Interpreter.java (added)
+++ commons/proper/jexl/branches/2.0/src/java/org/apache/commons/jexl/Interpreter.java Sun Oct 21 23:04:52 2007
@@ -0,0 +1,146 @@
+/*
+ * 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.
+ */
+
+package org.apache.commons.jexl;
+
+import java.util.Stack;
+
+import org.apache.commons.jexl.parser.ASTBitwiseAndNode;
+import org.apache.commons.jexl.parser.ASTBitwiseComplNode;
+import org.apache.commons.jexl.parser.ASTBitwiseOrNode;
+import org.apache.commons.jexl.parser.ASTBitwiseXorNode;
+import org.apache.commons.jexl.parser.ASTExpression;
+import org.apache.commons.jexl.parser.ASTExpressionExpression;
+import org.apache.commons.jexl.parser.ASTIdentifier;
+import org.apache.commons.jexl.parser.ASTIntegerLiteral;
+import org.apache.commons.jexl.parser.ASTNullLiteral;
+import org.apache.commons.jexl.parser.ASTReference;
+import org.apache.commons.jexl.parser.ASTReferenceExpression;
+import org.apache.commons.jexl.parser.ParserTreeConstants;
+import org.apache.commons.jexl.parser.SimpleNode;
+import org.apache.commons.jexl.parser.VisitorAdapter;
+import org.apache.commons.jexl.util.Coercion;
+import org.apache.commons.jexl.util.Introspector;
+import org.apache.commons.jexl.util.introspection.Uberspect;
+
+
+class Interpreter extends VisitorAdapter {
+
+    /** The uberspect. */
+    private Uberspect uberspect;
+
+    /** The context to store/retrieve variables. */
+    private JexlContext context;
+    
+    /** the stack that holds values during expressions */
+    private Stack valueStack;
+
+    //private Resolver resolver;
+
+    /**
+     * Create the interpreter with the default settings.
+     */
+    public Interpreter() {
+        super();
+        setUberspect(Introspector.getUberspect());
+    }
+
+    public Object interpret(SimpleNode node, JexlContext aContext) {
+        setContext(aContext);
+        valueStack = new Stack();
+        System.out.println("node is: " + node);
+        return node.jjtAccept(this, null);
+    }
+
+    public void setUberspect(Uberspect anUberspect)
+    {
+        uberspect = anUberspect;
+    }
+
+    protected Uberspect getUberspect()
+    {
+        return uberspect;
+    }
+
+    public void setContext(JexlContext aContext) {
+        context = aContext;
+    }
+
+    public Object visit(ASTBitwiseAndNode node, Object data) {
+        // evaluate left as long
+        Object left = ((SimpleNode) node.jjtGetChild(0)).jjtAccept(this, data);
+        // evaluate right as long
+        Object right = ((SimpleNode) node.jjtGetChild(1)).jjtAccept(this, data);
+        System.out.println("left is " + left + ", and right is " + right);
+        // coerce these two values longs and add.
+        long l = Coercion.coercelong(left);
+        long r = Coercion.coercelong(right);
+        return new Long(l & r);
+    }
+
+    public Object visit(ASTBitwiseComplNode node, Object data) { 
+        node.dump(" ");
+        Object left = node.jjtGetChild(0).jjtAccept(this, data);
+        long l = Coercion.coercelong(left);
+        return new Long(~l);
+    }
+    
+    public Object visit(ASTBitwiseOrNode node, Object data) { 
+        node.dump(" ");
+        Object left = node.jjtGetChild(0).jjtAccept(this, data);
+        Object right = node.jjtGetChild(1).jjtAccept(this, data);
+        long l = Coercion.coercelong(left);
+        long r = Coercion.coercelong(right);
+        return new Long(l | r);
+    }
+
+    public Object visit(ASTBitwiseXorNode node, Object data) { 
+        node.dump(" ");
+        Object left = node.jjtGetChild(0).jjtAccept(this, data);
+        Object right = node.jjtGetChild(1).jjtAccept(this, data);
+        long l = Coercion.coercelong(left);
+        long r = Coercion.coercelong(right);
+        return new Long(l ^ r);
+    }
+
+    public Object visit(ASTExpression node, Object data) { 
+        return node.jjtGetChild(0).jjtAccept(this, data);
+    }
+
+    public Object visit(ASTExpressionExpression node, Object data) {
+        return node.jjtGetChild(0).jjtAccept(this, data);
+    }
+
+    public Object visit(ASTIdentifier node, Object data) { 
+        node.dump(" ");
+        return context.getVars().get(node.image); 
+    }
+    
+    public Object visit(ASTIntegerLiteral node, Object data) { 
+        return Integer.valueOf(node.image); 
+    }
+
+    /** visit a 'null'. */
+    public Object visit(ASTNullLiteral node, Object data) { 
+        return null; 
+    }
+
+    public Object visit(ASTReference node, Object data) {
+        node.dump(" ");
+        return node.jjtGetChild(0).jjtAccept(this, data);
+    }
+}
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