Package dev.zemco.codegame.execution.instructions

Class AbstractCopyInstruction

java.lang.Object

dev.zemco.codegame.execution.instructions.AbstractCopyInstruction

All Implemented Interfaces:

IInstruction

Direct Known Subclasses:

CopyFromInstruction, CopyToInstruction

public abstract class AbstractCopyInstruction
extends Object
implements IInstruction

Abstract base for instruction copying values from one memory cell to some other.

Author:

Erik Zemčík

Constructor Summary

Constructors

Constructor	Description
AbstractCopyInstruction()

Method Summary

Modifier and Type	Method	Description
void	execute(IExecutionContext executionContext)	Copies the value from the source memory cell to the destination memory cell.
protected abstract IMemoryCell	getDestinationMemoryCell(IMemory memory)	Retrieves the destination memory cell for copying.
protected IMemoryCell	getMemoryCellAtAddress(IMemory memory, int address)	Retrieves a memory cell at a given address.
protected abstract IMemoryCell	getSourceMemoryCell(IMemory memory)	Retrieves the source memory cell for copying.

Methods inherited from class java.lang.Object

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

Constructor Details

AbstractCopyInstruction

public AbstractCopyInstruction()

Method Details

getSourceMemoryCell

protected abstract IMemoryCell getSourceMemoryCell(IMemory memory)
                                            throws InstructionExecutionException

Retrieves the source memory cell for copying.

Parameters:

memory - source of memory cells

Returns:

source memory cell

Throws:

InstructionExecutionException - if the source memory cell could not be retrieved

getDestinationMemoryCell

protected abstract IMemoryCell getDestinationMemoryCell(IMemory memory)
                                                 throws InstructionExecutionException

Retrieves the destination memory cell for copying.

Parameters:

memory - source of memory cells

Returns:

destination memory cell

Throws:

InstructionExecutionException - if the destination memory cell could not be retrieved

execute

public void execute(IExecutionContext executionContext)
             throws InstructionExecutionException

Copies the value from the source memory cell to the destination memory cell.

Internally these memory cells are resolved through the getSourceMemoryCell(IMemory) method and the getDestinationMemoryCell(IMemory) respectively.

Specified by:

execute in interface IInstruction

Parameters:

executionContext - context on which the instruction is executed

Throws:

IllegalArgumentException - if executionContext is null

InstructionExecutionException - if the source memory cell has no value

getMemoryCellAtAddress

protected IMemoryCell getMemoryCellAtAddress(IMemory memory,
 int address)
                                      throws InstructionExecutionException

Retrieves a memory cell at a given address. This method is intended to be used by subclasses as it provides formatted exceptions when the address is invalid for the given memory

Parameters:

memory - source of memory cells

address - address of the target memory cell

Returns:

memory cell at the given address

Throws:

InstructionExecutionException - if the address is out of bounds of the memory