operators
Class PSIfelse

java.lang.Object
  operators.PSIfelse

All Implemented Interfaces:

PSFlowOperator, PSObject, PSOperator

public class PSIfelse

extends java.lang.Object

implements PSFlowOperator

Implements PSFlowOperator interface.

Methods such as getOperatorToken() are inherited from PSFlowOperator interface which, in turn, are inherited from PSOperator. This concrete class is responsible for running an executable array if a condition is true, otherwise running an other.

Constructor Summary

PSIfelse()

Method Summary

void	action(PSStack s) Rus an executable array if the boolean value is true or another if it is false.
java.lang.String	getOperatorToken() Returns the token identifying this operator.
boolean	isValid(PSStack s) Checks if it valid to use this operator now.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

PSIfelse

public PSIfelse()

Method Detail

getOperatorToken

public java.lang.String getOperatorToken()

Returns the token identifying this operator.

Returns the name of the operand that this concrete class simulates, here "ifelse".

Precondition : A valid operator class has been created.
Postcondition : A string is returned, labeling the semantics of this class.

Specified by:

getOperatorToken in interface PSOperator

Returns:

The token identifying this operator.

isValid

public boolean isValid(PSStack s)
                throws PSSyntaxException

Checks if it valid to use this operator now.

If can occur only if a boolean value and two executable arrays are given.

Precondition : A valid instance of PSStack with a PSBoolean and 2 executable arrays on top.
Postcondition : A reply to the question whether the operator can perfom its defined behaviour.

Specified by:

isValid in interface PSOperator

Parameters:

s - A reference to PSStack instance.

Returns:

True if the operation can be executed, false otherwise.

Throws:

PSSyntaxException - The syntax of the token is wrong.

action

public void action(PSStack s)

Rus an executable array if the boolean value is true or another if it is false.

Precondition : A valid stack is given to method with a PSBoolean and 2 executable arrays on top.
Postcondition : The first array will be executed if the boolean value is true, otherwise the second.

Specified by:

action in interface PSFlowOperator

Parameters:

s - The Runtime Stack which contains the boolean value and the arrays.