PFSA

Class PFSASimulator

java.lang.Object

FSA.Simulator

PFSA.PFSASimulator

public class PFSASimulator
extends Simulator

Extends the Simulator by changing the notion of validity of a transition, also handling fresh names. Overrides various methods

Author:

Davide Basile

Field Summary

Fields

Modifier and Type	Field and Description
(package private) java.util.Vector<java.lang.Integer>	fresh

Fields inherited from class FSA.Simulator

automa, pointer_state, pointer_string

Constructor Summary

Constructors

Constructor and Description
PFSASimulator(FSA automa)

Method Summary

Methods

Modifier and Type	Method and Description
void	changeAutoma(FSA automa) Change the automaton
protected Continuation	createContinuation() Create a new Continuation with the freezed state of the automaton
protected boolean	isValid(Transition tr, int symbol) A transition tr with symbol in input is valid if : sigma=T, stack not empty, top fresh or top equals to symbol in input sigma=i , register i not empty and available, top fresh or top equals to symbol in input sigma=square Z=i, stack and register i not empty, top stack = top register i Z=?
protected void	restoreStateContinuation(Continuation c) restore the state of the simulator with the parameters in the continuation C.
protected boolean	sideConditions() As a side conditions in the final state when the string in input is consumed the automaton must have the empty stack
protected void	updateState(Transition t, int symbol) Update the state of the simulator by performing the transition tr

Methods inherited from class FSA.Simulator

backtracking, checkContinuation, contains, contains, run, step

Methods inherited from class java.lang.Object

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

Field Detail

fresh

java.util.Vector<java.lang.Integer> fresh

Constructor Detail

PFSASimulator

public PFSASimulator(FSA automa)

Parameters:

automa - the automaton to simulate

Method Detail

changeAutoma

public void changeAutoma(FSA automa)

Change the automaton

Overrides:

changeAutoma in class Simulator

sideConditions

protected boolean sideConditions()

As a side conditions in the final state when the string in input is consumed the automaton must have the empty stack

Overrides:

sideConditions in class Simulator

Returns:

true

isValid

protected boolean isValid(Transition tr,
              int symbol)

A transition tr with symbol in input is valid if :

• sigma=T, stack not empty, top fresh or top equals to symbol in input
• sigma=i , register i not empty and available, top fresh or top equals to symbol in input
• sigma=square

• Z=i, stack and register i not empty, top stack = top register i
• Z=?, stack not empty
• Z=square

• zeta=i, register i not empty, top register i available
• zeta=square
• delta=-i
• delta=+i
• delta=square

Overrides:

isValid in class Simulator

Parameters:

tr - transition to be performed

symbol - symbol in input

Returns:

true if the transition is valid

updateState

protected void updateState(Transition t,
               int symbol)

Update the state of the simulator by performing the transition tr

Overrides:

updateState in class Simulator

Parameters:

t - the transition to be performed

symbol - the symbol in input

restoreStateContinuation

protected void restoreStateContinuation(Continuation c)

restore the state of the simulator with the parameters in the continuation C. First invoke the method of the super class and then update the register of the automaton with a copy of the register stored in the continuation.

Overrides:

restoreStateContinuation in class Simulator

Parameters:

c - the continuation to be restored

createContinuation

protected Continuation createContinuation()

Create a new Continuation with the freezed state of the automaton

Overrides:

createContinuation in class Simulator

Returns:

a new Continuation with the actual state of the simulator freezed