/*
***************************************************************************************
* Copyright (C) 2006 EsperTech, Inc. All rights reserved. *
* http://www.espertech.com/esper *
* http://www.espertech.com *
* ---------------------------------------------------------------------------------- *
* The software in this package is published under the terms of the GPL license *
* a copy of which has been included with this distribution in the license.txt file. *
***************************************************************************************
*/
package com.espertech.esper.client.soda;
import java.io.Serializable;
import java.io.StringWriter;
import java.util.List;
/**
* Represents a single expression declaration that applies to a given statement.
*/
public class ExpressionDeclaration implements Serializable {
private static final long serialVersionUID = 8445897497101986441L;
private String name;
private List<String> parameterNames;
private Expression expression;
private boolean alias;
/**
* Ctor.
*/
public ExpressionDeclaration() {
}
/**
* Ctor.
*
* @param name of expression
* @param parameterNames expression paramater names
* @param expression the expression body
* @param alias indicator whether this is an expression alias or not
*/
public ExpressionDeclaration(String name, List<String> parameterNames, Expression expression, boolean alias) {
this.name = name;
this.parameterNames = parameterNames;
this.expression = expression;
this.alias = alias;
}
/**
* Returns expression name.
*
* @return name
*/
public String getName() {
return name;
}
/**
* Sets expression name.
*
* @param name name to set
*/
public void setName(String name) {
this.name = name;
}
/**
* Returns the expression body.
*
* @return expression body
*/
public Expression getExpression() {
return expression;
}
/**
* Sets the expression body.
*
* @param expression body to set
*/
public void setExpression(Expression expression) {
this.expression = expression;
}
/**
* Returns the paramater names.
*
* @return paramater names
*/
public List<String> getParameterNames() {
return parameterNames;
}
/**
* Returns indicator whether the expression is an alias or not.
*
* @return alias indicator
*/
public boolean isAlias() {
return alias;
}
/**
* Sets indicator whether the expression is an alias or not.
*
* @param alias alias indicator
*/
public void setAlias(boolean alias) {
this.alias = alias;
}
/**
* Sets the paramater names.
*
* @param parameterNames paramater names to set
*/
public void setParameterNames(List<String> parameterNames) {
this.parameterNames = parameterNames;
}
/**
* Print.
*
* @param writer to print to
* @param expressionDeclarations expression declarations
* @param formatter for newline-whitespace formatting
*/
public static void toEPL(StringWriter writer, List<ExpressionDeclaration> expressionDeclarations, EPStatementFormatter formatter) {
if ((expressionDeclarations == null) || (expressionDeclarations.isEmpty())) {
return;
}
for (ExpressionDeclaration part : expressionDeclarations) {
if (part.getName() == null) {
continue;
}
formatter.beginExpressionDecl(writer);
part.toEPL(writer);
}
}
/**
* Print part.
*
* @param writer to write to
*/
public void toEPL(StringWriter writer) {
writer.append("expression ");
writer.append(name);
if (alias) {
writer.append(" alias for");
}
writer.append(" {");
if (!alias) {
if (parameterNames != null && parameterNames.size() == 1) {
writer.append(parameterNames.get(0));
} else if (parameterNames != null && !parameterNames.isEmpty()) {
String delimiter = "";
writer.append("(");
for (String name : parameterNames) {
writer.append(delimiter);
writer.append(name);
delimiter = ",";
}
writer.append(")");
}
if (parameterNames != null && !parameterNames.isEmpty()) {
writer.append(" => ");
}
}
if (expression != null) {
expression.toEPL(writer, ExpressionPrecedenceEnum.MINIMUM);
}
writer.append("}");
}
}