slogo.instruction

Class BK

java.lang.Object

slogo.GrammarElement

slogo.instruction.Instruction

slogo.instruction.BK

public class BK
extends Instruction

The Back instruction

Field Summary

Fields

Modifier and Type	Field and Description
private GrammarElement	expression

Fields inherited from class slogo.GrammarElement

gelementsToValue, subroutineNames

Constructor Summary

Constructors

Constructor and Description
BK(GrammarElement e)

Method Summary

Modifier and Type	Method and Description
java.lang.Object	evaluate(Context c) Evaluate this language construct in some context.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

expression

private GrammarElement expression

Constructor Detail

BK

public BK(GrammarElement e)

Parameters:

e - the argument to the expression

Method Detail

evaluate

public java.lang.Object evaluate(Context c)

Description copied from class: GrammarElement

Evaluate this language construct in some context. The evaluation may have side-effects, e.g., moving a turtle.

Specified by:

evaluate in class Instruction

Parameters:

c - context in which the evaluation takes place

Returns:

the result of evaluating the construct

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

Returns:

a String representing this instruction as BK, followed by the expression