slogo.instruction

Class Right

java.lang.Object

slogo.GrammarElement

slogo.instruction.Instruction

slogo.instruction.Right

public class Right
extends Instruction

A RIGHT instruction has one component: a GrammarElement that represents the number of degrees to turn the turtle to the right. To evaluate a RIGHT instruction the expression is evaluated first, this determines the double version of the degrees. The turtle's heading is then set using those degrees.

The value returned by evaluating a RIGHT instruction is the expression itself, representing the degrees to turn the turtle to the right.

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
Right(GrammarElement e) Constructs a RIGHT 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

Right

public Right(GrammarElement e)

Constructs a RIGHT instruction that can be executed.

Parameters:

e - number of degrees to turn to the right

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:

the degrees moved to the right

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

Returns:

a String representing this instruction as RT, followed by the expression about the degrees turned to the right