org.zmpp.vm
Class VariableInstruction

java.lang.Object
  org.zmpp.vm.AbstractInstruction
      org.zmpp.vm.VariableInstruction

All Implemented Interfaces:

Instruction

public class VariableInstruction
extends AbstractInstruction

This class represents instructions of type VARIABLE.

Version:

1.0

Author:

Wei-ju Wu

Nested Class Summary

Nested classes/interfaces inherited from class org.zmpp.vm.AbstractInstruction

AbstractInstruction.InstructionForm, AbstractInstruction.OperandCount

Field Summary

static int	OP_CALL List of opcodes.
static int	OP_INPUTSTREAM
static int	OP_OUTPUTSTREAM
static int	OP_PRINT_CHAR
static int	OP_PRINT_NUM
static int	OP_PULL
static int	OP_PUSH
static int	OP_PUT_PROP
static int	OP_RANDOM
static int	OP_SET_WINDOW
static int	OP_SOUND_EFFECT
static int	OP_SPLIT_WINDOW
static int	OP_SREAD
static int	OP_STOREB
static int	OP_STOREW

Fields inherited from class org.zmpp.vm.AbstractInstruction

FALSE, TRUE

Constructor Summary

VariableInstruction(Machine machineState, AbstractInstruction.OperandCount operandCount, int opcode)
Constructor.

Method Summary

void	execute() Execute the instruction.
AbstractInstruction.InstructionForm	getInstructionForm() Returns the instruction's form.
AbstractInstruction.OperandCount	getOperandCount() Returns the instruction's operand count type.
boolean	storesResult() Returns true, if this instruction stores a result, false, otherwise.

Methods inherited from class org.zmpp.vm.AbstractInstruction

addOperand, branchIfTrue, branchOnTest, getBranchOffset, getLength, getMachine, getNumOperands, getOpcode, getOperand, getStoreVariable, getUnsignedValue, getValue, isBranch, nextInstruction, returnFromRoutine, setBranchIfTrue, setBranchOffset, setLength, setOpcode, setStoreVariable, storeResult, throwInvalidOpcode

Methods inherited from class java.lang.Object

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

Field Detail

OP_CALL

public static final int OP_CALL

List of opcodes. See Z-Machine Standards document 1.0 for explanations.

See Also:

Constant Field Values

OP_STOREW

public static final int OP_STOREW

See Also:

Constant Field Values

OP_STOREB

public static final int OP_STOREB

See Also:

Constant Field Values

OP_PUT_PROP

public static final int OP_PUT_PROP

See Also:

Constant Field Values

OP_SREAD

public static final int OP_SREAD

See Also:

Constant Field Values

OP_PRINT_CHAR

public static final int OP_PRINT_CHAR

See Also:

Constant Field Values

OP_PRINT_NUM

public static final int OP_PRINT_NUM

See Also:

Constant Field Values

OP_RANDOM

public static final int OP_RANDOM

See Also:

Constant Field Values

OP_PUSH

public static final int OP_PUSH

See Also:

Constant Field Values

OP_PULL

public static final int OP_PULL

See Also:

Constant Field Values

OP_SPLIT_WINDOW

public static final int OP_SPLIT_WINDOW

See Also:

Constant Field Values

OP_SET_WINDOW

public static final int OP_SET_WINDOW

See Also:

Constant Field Values

OP_OUTPUTSTREAM

public static final int OP_OUTPUTSTREAM

See Also:

Constant Field Values

OP_INPUTSTREAM

public static final int OP_INPUTSTREAM

See Also:

Constant Field Values

OP_SOUND_EFFECT

public static final int OP_SOUND_EFFECT

See Also:

Constant Field Values

Constructor Detail

VariableInstruction

public VariableInstruction(Machine machineState,
                           AbstractInstruction.OperandCount operandCount,
                           int opcode)

Constructor.

Parameters:

machineState - a reference to a MachineState object

operandCount - the operand count

opcode - the instruction's opcode

Method Detail

getInstructionForm

public AbstractInstruction.InstructionForm getInstructionForm()

Returns the instruction's form.

Specified by:

getInstructionForm in class AbstractInstruction

Returns:

the instruction form

getOperandCount

public AbstractInstruction.OperandCount getOperandCount()

Returns the instruction's operand count type.

Specified by:

getOperandCount in class AbstractInstruction

Returns:

the operand count type

storesResult

public boolean storesResult()

Returns true, if this instruction stores a result, false, otherwise.

Overrides:

storesResult in class AbstractInstruction

Returns:

true if a result is stored, false otherwise

execute

public void execute()

Execute the instruction.