slogo.instruction

Class PenUp

java.lang.Object

slogo.GrammarElement

slogo.instruction.Instruction

slogo.instruction.PenUp

public class PenUp
extends Instruction

A PENUP instruction has no components: when called, it puts the pen up, which takes away the turtle's drawing functionality. To evaluate a PENUP instruction, the setPenUp method is called on the turtle.

The value returned by evaluating a PENUP instruction is the expression itself.

Field Summary

Fields inherited from class slogo.GrammarElement

gelementsToValue

Constructor Summary

Constructors

Constructor and Description
PenUp()

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

Constructor Detail

PenUp

public PenUp()

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:

null

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

Returns:

a String representing this instruction as PENUP