slogo.instruction

Class Instruction

java.lang.Object

slogo.GrammarElement

slogo.instruction.Instruction

Direct Known Subclasses:

ArithmeticInstruction, Back, Clean, ClearScreen, Difference, EqualBool, Forward, Greater, Heading, HideTurtle, Home, If, Left, Less, Minus, NotEqual, PenDown, PenDownP, PenUp, Print, Product, Quotient, Remainder, Repeat, Right, SetX, SetXY, SetY, ShowTurtle, StrictInstructionList, Sum, To, Towards, Xcor, Ycor

public abstract class Instruction
extends GrammarElement

Represents an instruction in the SLogo language

Field Summary

Fields inherited from class slogo.GrammarElement

gelementsToValue

Constructor Summary

Constructors

Constructor and Description
Instruction()

Method Summary

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

Methods inherited from class java.lang.Object

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

Constructor Detail

Instruction

public Instruction()

Method Detail

evaluate

public abstract 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 GrammarElement

Parameters:

c - context in which the evaluation takes place

Returns:

the result of evaluating the construct