gnu.prolog.vm.interpreter.instruction
Class IDup

java.lang.Object
  gnu.prolog.vm.interpreter.instruction.Instruction
      gnu.prolog.vm.interpreter.instruction.IDup

All Implemented Interfaces:

Installable

public class IDup
extends Instruction

duplicate top of pushdown stack

Field Summary

Fields inherited from class gnu.prolog.vm.interpreter.instruction.Instruction

codePosition

Constructor Summary

IDup()

Method Summary

int	execute(ExecutionState state, BacktrackInfo bi) execute call instruction within specified sate
String	toString() convert instruction to string

Methods inherited from class gnu.prolog.vm.interpreter.instruction.Instruction

install, uninstall

Methods inherited from class java.lang.Object

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

Constructor Detail

IDup

public IDup()

Method Detail

execute

public int execute(ExecutionState state,
                   BacktrackInfo bi)
            throws PrologException

execute call instruction within specified sate

Specified by:

execute in class Instruction

Parameters:

state - state within which instruction will be executed

Returns:

instruction to caller how to execute next instruction

Throws:

PrologException - if code is throwing prolog exception

toString

public String toString()

convert instruction to string

Overrides:

toString in class Object