slogo.instruction

Class SetX

java.lang.Object

slogo.GrammarElement

slogo.instruction.Instruction

slogo.instruction.SetX

public class SetX
extends Instruction

A SETX instruction has one component: a GrammarElement that represents the x coordinate to set. To evaluate a SETX instruction the expression is evaluated first, this determines the double version of the x coordinate. The turtle's coordinates are then reset and the turtle is moved to the new x and pre-existing y coordinates.

The value returned by evaluating a SETX instruction is the instruction itself.

Field Summary

Fields

Modifier and Type	Field and Description
private GrammarElement	expression

Fields inherited from class slogo.GrammarElement

gelementsToValue

Constructor Summary

Constructors

Constructor and Description
SetX(GrammarElement g) Constructs a SETX 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

expression

private GrammarElement expression

Constructor Detail

SetX

public SetX(GrammarElement g)

Constructs a SETX instruction that can be executed.

Parameters:

g - the new x coordinate

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:

string version of new point

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

Returns:

a String representing this instruction as SETX