de.unidu.is.expressions
Class Arg2Expression

java.lang.Object
  de.unidu.is.expressions.AbstractExpression
      de.unidu.is.expressions.Arg2Expression

All Implemented Interfaces:

Expression

Direct Known Subclasses:

DifferenceExpression, EqualsExpression, FractionExpression, ProductExpression, SumExpression

public class Arg2Expression

extends AbstractExpression

An expression with an operator and two arguments, e.g. the sum of two expressions.

Since:

2003-10-27

Version:

$Revision: 1.5 $, $Date: 2005/02/21 17:29:18 $

Author:

Henrik Nottelmann

Field Summary

protected Expression	arg1 First argument of this expression.
protected Expression	arg2 Second argument of this expression.
protected java.lang.String	op Expression operator.

Constructor Summary

Arg2Expression(java.lang.String op, Expression arg1, Expression arg2)
Creates a new expression object.

Method Summary

Expression	getArg1() Returns the first argument.
Expression	getArg2() Returns the second argument.
java.lang.String	getOp() Returns the operator symbol.
java.lang.String	getSQLTemplate() Returns a string representation for this expression which can be used as a template in an SQL statement.
Expression	substitute(java.util.Map binding) Performs an substitution for variables, e.g. for each key variable in the specified binding, all occurences of ${key} are replaced by the corresponding value in the map.
java.lang.String	toString() Returns the expression in infix notation, embedded in round brackets.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

op

protected java.lang.String op

Expression operator.

arg1

protected Expression arg1

First argument of this expression.

arg2

protected Expression arg2

Second argument of this expression.

Constructor Detail

Arg2Expression

public Arg2Expression(java.lang.String op,
                      Expression arg1,
                      Expression arg2)

Creates a new expression object.

Parameters:

op - expression operator

arg1 - first argument of this expression

arg2 - second argument of this expression

Method Detail

substitute

public Expression substitute(java.util.Map binding)

Performs an substitution for variables, e.g. for each key variable in the specified binding, all occurences of ${key} are replaced by the corresponding value in the map.

Only the arguments are substituted.

Specified by:

substitute in interface Expression

Overrides:

substitute in class AbstractExpression

Parameters:

binding - variable binding

Returns:

expression after substitution

toString

public java.lang.String toString()

Returns the expression in infix notation, embedded in round brackets.

Returns:

expression as a string

getSQLTemplate

public java.lang.String getSQLTemplate()

Returns a string representation for this expression which can be used as a template in an SQL statement.

Specified by:

getSQLTemplate in interface Expression

Overrides:

getSQLTemplate in class AbstractExpression

Returns:

template for SQL statements

getArg1

public Expression getArg1()

Returns the first argument.

Returns:

first argument

getArg2

public Expression getArg2()

Returns the second argument.

Returns:

second argument

getOp

public java.lang.String getOp()

Returns the operator symbol.

Returns:

operator symbol