slogo.instruction

Class Greater

java.lang.Object

slogo.GrammarElement

slogo.instruction.Instruction

slogo.instruction.Greater

public class Greater
extends Instruction

A GREATER instruction has two components: a GrammarElement that represents the first double and a GrammarElement that represents the second double To evaluate a GREATER instruction the expressions are evaluated first, this determines then double version of the numbers. If the first number is greater than the second number, return 1; else return 0.

The value returned by evaluating a GREATER instruction is the expression itself, representing the first and second GrammarElement.

Field Summary

Fields

Modifier and Type	Field and Description
private GrammarElement	expressionOne
private GrammarElement	expressionTwo

Fields inherited from class slogo.GrammarElement

gelementsToValue

Constructor Summary

Constructors

Constructor and Description
Greater(GrammarElement e, GrammarElement f) Constructs a GREATER instruction that can be executed.

Method Summary

Modifier and Type	Method and Description
java.lang.Object	evaluate(Context c) Evaluate this instruction in a Context.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

expressionOne

private GrammarElement expressionOne

expressionTwo

private GrammarElement expressionTwo

Constructor Detail

Greater

public Greater(GrammarElement e,
               GrammarElement f)

Constructs a GREATER instruction that can be executed.

Parameters:

e - the first number to compare

f - the second number to compare

Method Detail

evaluate

public java.lang.Object evaluate(Context c)

Evaluate this instruction in a Context.

Specified by:

evaluate in class Instruction

Parameters:

c - the Context for the evaluation

Returns:

0 or 1, depending on the values of the the expressions

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

Returns:

a String representing this instruction as GREATER, followed by the two expressions