slogo.instruction

Class StrictInstructionList

java.lang.Object

slogo.GrammarElement

slogo.instruction.Instruction

slogo.instruction.StrictInstructionList

public class StrictInstructionList
extends Instruction

A list of instructions that doesn't include a function definition. This is the definition of Strict, an instruction list can include any instruction, including a function definition, whereas a strict instruction list doesn't include these.

Constructing a strict instruction list is usually accomplished by creating an object and repeatedly calling add to add new instructions. The order in which instructions are added is the order in which they'll be executed.

Field Summary

Fields

Modifier and Type	Field and Description
private java.util.List<Instruction>	myInstructionList

Fields inherited from class slogo.GrammarElement

gelementsToValue

Constructor Summary

Constructors

Constructor and Description
StrictInstructionList() Construct an empty list of instructions.

Method Summary

Modifier and Type	Method and Description
void	add(Instruction instruction) Add an instruction to this list (FIFO order for execution).
java.lang.Object	evaluate(Context c) Evaluate this instruction in a Context, return the result of the evaluation (the result is the last instruction executed).
java.util.Iterator<Instruction>	iterator() Return an iterator for accessing all the instructions.
java.lang.String	toString() Return a string indicating the # of instructions in the list

Methods inherited from class java.lang.Object

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

Field Detail

myInstructionList

private java.util.List<Instruction> myInstructionList

Constructor Detail

StrictInstructionList

public StrictInstructionList()

Construct an empty list of instructions.

Method Detail

add

public void add(Instruction instruction)

Add an instruction to this list (FIFO order for execution).

Parameters:

instruction - the instruction added.

evaluate

public java.lang.Object evaluate(Context c)

Evaluate this instruction in a Context, return the result of the evaluation (the result is the last instruction executed).

Specified by:

evaluate in class Instruction

Parameters:

c - the context for the evaluation

Returns:

the result of evaluating the last expression in the list

iterator

public java.util.Iterator<Instruction> iterator()

Return an iterator for accessing all the instructions.

Returns:

an iterator for accessing the instructions

toString

public java.lang.String toString()

Return a string indicating the # of instructions in the list

Overrides:

toString in class java.lang.Object

Returns:

"[list of size = # instructions]"