gnu.prolog.vm.interpreter.instruction
Class ICall

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

All Implemented Interfaces:

Installable, PrologCodeListener, EventListener

public class ICall
extends Instruction
implements PrologCodeListener

call instruction.

Field Summary

PrologCode	code code to call, if predicate is dynamic it changes after each update
CompoundTermTag	tag tag of predicate to call

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

codePosition

Constructor Summary

ICall(CompoundTermTag tag)
a constructor

Method Summary

protected void	ensureLoaded(Environment env) ensure that code is loaded in predicate
int	execute(ExecutionState state, BacktrackInfo bi) execute call instruction within specified sate
void	install(Environment env) install instruction to environment
void	prologCodeUpdated(PrologCodeUpdatedEvent evt) notify instruction that prolog code for predicate was updated
String	toString() convert instruction to string
void	uninstall(Environment env) uninstall instruction from environment

Methods inherited from class java.lang.Object

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

Field Detail

tag

public CompoundTermTag tag

tag of predicate to call

code

public transient PrologCode code

code to call, if predicate is dynamic it changes after each update

Constructor Detail

ICall

public ICall(CompoundTermTag tag)

a constructor

Parameters:

tag -

Method Detail

toString

public String toString()

convert instruction to string

Overrides:

toString in class Object

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

prologCodeUpdated

public void prologCodeUpdated(PrologCodeUpdatedEvent evt)

notify instruction that prolog code for predicate was updated

Specified by:

prologCodeUpdated in interface PrologCodeListener

install

public void install(Environment env)

install instruction to environment

Specified by:

install in interface Installable

Overrides:

install in class Instruction

Parameters:

env - Environment to install the predicate

uninstall

public void uninstall(Environment env)

uninstall instruction from environment

Specified by:

uninstall in interface Installable

Overrides:

uninstall in class Instruction

Parameters:

env - Environment to install the predicate

ensureLoaded

protected void ensureLoaded(Environment env)
                     throws PrologException

ensure that code is loaded in predicate

Parameters:

env -

Throws:

PrologException