slogo.instruction

Class IF

java.lang.Object

slogo.GrammarElement

slogo.instruction.Instruction

slogo.instruction.IF

public class IF
extends Instruction

Field Summary

Fields

Modifier and Type	Field and Description
private StrictInstructionList	instructionList
private GrammarElement	statement

Fields inherited from class slogo.GrammarElement

gelementsToValue

Constructor Summary

Constructors

Constructor and Description
IF(GrammarElement e, StrictInstructionList sil) Constructs an IF 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

statement

private GrammarElement statement

instructionList

private StrictInstructionList instructionList

Constructor Detail

IF

public IF(GrammarElement e,
          StrictInstructionList sil)

Constructs an IF instruction that can be executed.

Parameters:

e - grammar element

sil - strict instruction list that is the body

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 result of evaluating the instruction list the last time

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

Returns:

a String representing this instruction as IF, followed by the expression about the condition and the list of instructions