01: /*
02: * Copyright 2002-2006 The Apache Software Foundation.
03: *
04: * Licensed under the Apache License, Version 2.0 (the "License");
05: * you may not use this file except in compliance with the License.
06: * You may obtain a copy of the License at
07: *
08: * http://www.apache.org/licenses/LICENSE-2.0
09: *
10: * Unless required by applicable law or agreed to in writing, software
11: * distributed under the License is distributed on an "AS IS" BASIS,
12: * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13: * See the License for the specific language governing permissions and
14: * limitations under the License.
15: */
16:
17: package org.apache.commons.jexl.parser;
18:
19: import org.apache.commons.jexl.JexlContext;
20: import org.apache.commons.jexl.util.Coercion;
21:
22: /**
23: * A while loop. Syntax: while ( expression ) statement
24: *
25: * @author Dion Gillard
26: * @since 1.1
27: */
28: public class ASTWhileStatement extends SimpleNode {
29: /**
30: * Create the node given an id.
31: *
32: * @param id node id.
33: */
34: public ASTWhileStatement(int id) {
35: super (id);
36: }
37:
38: /**
39: * Create a node with the given parser and id.
40: *
41: * @param p a parser.
42: * @param id node id.
43: */
44: public ASTWhileStatement(Parser p, int id) {
45: super (p, id);
46: }
47:
48: /** {@inheritDoc} */
49: public Object jjtAccept(ParserVisitor visitor, Object data) {
50: return visitor.visit(this , data);
51: }
52:
53: /** {@inheritDoc} */
54: public Object value(JexlContext jc) throws Exception {
55: Object result = null;
56: /* first child is the expression */
57: SimpleNode expressionNode = (SimpleNode) jjtGetChild(0);
58: while (Coercion.coerceBoolean(expressionNode.value(jc))
59: .booleanValue()) {
60: // execute statement
61: result = ((SimpleNode) jjtGetChild(1)).value(jc);
62: }
63:
64: return result;
65: }
66: }
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