slogo.instruction

Class FD

java.lang.Object

slogo.GrammarElement

slogo.instruction.Instruction

slogo.instruction.FD

public class FD
extends Instruction

Field Summary

Fields

Modifier and Type	Field and Description
private Expression	FDExpression

Fields inherited from class slogo.GrammarElement

gelementsToValue

Constructor Summary

Constructors

Constructor and Description
FD(Expression e) Constructs a FD instruction that can be executed.

Method Summary

Methods

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

FDExpression

private Expression FDExpression

Constructor Detail

FD

public FD(Expression e)

Constructs a FD instruction that can be executed.

Parameters:

e - number of steps to move forward

Method Detail

evaluate

public java.lang.Object evaluate(Context c)

Evaluate this instruction in a Context.

Overrides:

evaluate in class Instruction

Parameters:

c - the Context for the evaluation

Returns:

the result of evaluating the instruction list the last time

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

Returns:

a String representing this instruction as FORWARD, followed by the expression about how many times to repeat the instructions and the list of instructions