/*
* Copyright 1999-2012 Alibaba Group.
*
* Licensed 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.
*/
/**
* (created at 2011-4-12)
*/
package com.alibaba.cobar.parser.ast.expression.primary.function;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import com.alibaba.cobar.parser.ast.expression.Expression;
import com.alibaba.cobar.parser.ast.expression.primary.PrimaryExpression;
import com.alibaba.cobar.parser.visitor.SQLASTVisitor;
/**
* @author <a href="mailto:shuo.qius@alibaba-inc.com">QIU Shuo</a>
*/
public abstract class FunctionExpression extends PrimaryExpression {
protected static List<Expression> wrapList(Expression expr) {
List<Expression> list = new ArrayList<Expression>(1);
list.add(expr);
return list;
}
/**
* <code>this</code> function object being called is a prototype
*/
public abstract FunctionExpression constructFunction(List<Expression> arguments);
protected final String functionName;
protected final List<Expression> arguments;
public FunctionExpression(String functionName, List<Expression> arguments) {
super();
this.functionName = functionName;
if (arguments == null || arguments.isEmpty()) {
this.arguments = Collections.emptyList();
} else {
if (arguments instanceof ArrayList) {
this.arguments = arguments;
} else {
this.arguments = new ArrayList<Expression>(arguments);
}
}
}
public void init() {
}
/**
* @return never null
*/
public List<Expression> getArguments() {
return arguments;
}
public String getFunctionName() {
return functionName;
}
@Override
public Expression setCacheEvalRst(boolean cacheEvalRst) {
return super.setCacheEvalRst(cacheEvalRst);
}
@Override
public void accept(SQLASTVisitor visitor) {
visitor.visit(this);
}
}