001 /*
002 // $Id: ParameterNode.java 482 2012-01-05 23:27:27Z jhyde $
003 //
004 // Licensed to Julian Hyde under one or more contributor license
005 // agreements. See the NOTICE file distributed with this work for
006 // additional information regarding copyright ownership.
007 //
008 // Julian Hyde licenses this file to you under the Apache License,
009 // Version 2.0 (the "License"); you may not use this file except in
010 // compliance with the License. You may obtain a copy of the License at:
011 //
012 // http://www.apache.org/licenses/LICENSE-2.0
013 //
014 // Unless required by applicable law or agreed to in writing, software
015 // distributed under the License is distributed on an "AS IS" BASIS,
016 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
017 // See the License for the specific language governing permissions and
018 // limitations under the License.
019 */
020 package org.olap4j.mdx;
021
022 import org.olap4j.type.Type;
023
024 import java.io.PrintWriter;
025
026 /**
027 * A parameter to an MDX query.
028 *
029 * <p>Not all dialects of MDX support parameters. If a dialect supports
030 * parameters, the driver for that dialect should extend the parser to
031 * introduce a ParameterNode into the parse tree wherever a parameter is
032 * encountered.
033 *
034 * <p>For example, in Mondrian's dialect of MDX, a call to the <code>Param(name,
035 * type, defaultValueExpr)</code> function introduces a parameter, and
036 * <code>ParamRef(name)</code> creates a reference to a parameter defined
037 * elsewhere in the query.
038 *
039 * @version $Id: ParameterNode.java 482 2012-01-05 23:27:27Z jhyde $
040 */
041 public class ParameterNode implements ParseTreeNode {
042 private String name;
043 private Type type;
044 private ParseTreeNode defaultValueExpression;
045 private final ParseRegion region;
046
047 /**
048 * Creates a ParameterNode.
049 *
050 * <p>The <code>name</code> must not be null, and the
051 * <code>defaultValueExpression</code> must be consistent with the
052 * <code>type</code>.
053 *
054 * @param region Region of source code
055 * @param name Name of parameter
056 * @param type Type of parameter
057 * @param defaultValueExpression Expression which yields the default value
058 * of the parameter
059 */
060 public ParameterNode(
061 ParseRegion region,
062 String name,
063 Type type,
064 ParseTreeNode defaultValueExpression)
065 {
066 assert name != null;
067 assert type != null;
068 assert defaultValueExpression != null;
069 this.region = region;
070 this.name = name;
071 this.type = type;
072 this.defaultValueExpression = defaultValueExpression;
073 }
074
075 public ParseRegion getRegion() {
076 return region;
077 }
078
079 public <T> T accept(ParseTreeVisitor<T> visitor) {
080 final T t = visitor.visit(this);
081 defaultValueExpression.accept(visitor);
082 return t;
083 }
084
085 public void unparse(ParseTreeWriter writer) {
086 PrintWriter pw = writer.getPrintWriter();
087 pw.print("Param(");
088 pw.print(MdxUtil.quoteForMdx(name));
089 pw.print(", ");
090 pw.print(type);
091 pw.print(", ");
092 defaultValueExpression.unparse(writer);
093 pw.print(")");
094 }
095
096 public Type getType() {
097 // not an expression
098 return null;
099 }
100
101 /**
102 * Returns the name of this parameter.
103 *
104 * @return name of this parameter
105 */
106 public String getName() {
107 return name;
108 }
109
110 /**
111 * Sets the name of this parameter.
112 *
113 * @param name Parameter name
114 */
115 public void setName(String name) {
116 this.name = name;
117 }
118
119 /**
120 * Sets the type of this parameter.
121 *
122 * @param type Type
123 */
124 public void setType(Type type) {
125 this.type = type;
126 }
127
128
129 /**
130 * Returns the expression which yields the default value of this parameter.
131 *
132 * @return expression which yields the default value of this parameter
133 */
134 public ParseTreeNode getDefaultValueExpression() {
135 return defaultValueExpression;
136 }
137
138 /**
139 * Sets the expression which yields the default value of this parameter.
140 *
141 * @param defaultValueExpression default value expression
142 */
143 public void setDefaultValueExpression(ParseTreeNode defaultValueExpression)
144 {
145 this.defaultValueExpression = defaultValueExpression;
146 }
147
148 public ParameterNode deepCopy() {
149 return new ParameterNode(
150 this.region,
151 this.name,
152 this.type, // types are immutable
153 this.defaultValueExpression.deepCopy());
154 }
155 }
156
157 // End ParameterNode.java