Package org.zkoss.zats.common.select.impl.fsm

Class StateMachine<E,C,IN>

java.lang.Object

org.zkoss.zats.common.select.impl.fsm.StateMachine<E,C,IN>

public abstract class StateMachine<E,C,IN>
extends Object

A Finite State Machine implementation. This state machine is callback based, which differs from the standard FSM from textbook. Easier to use and faster to develop and debug.

Since:

6.0.0

Author:

simonpai

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	StateMachine.StateMachineException

Field Summary

Fields

Modifier and Type	Field	Description
protected E	_current
protected boolean	_debug
protected boolean	_run
protected Map<E,StateCtx<E,C,IN>>	_states
protected int	_step

Constructor Summary

Constructors

Constructor	Description
StateMachine()	Construct a state machine

Method Summary

Modifier and Type	Method	Description
protected void	afterStep(IN input, C inputClass, E origin, E destination)	This method is called after executing a step
protected void	beforeStep(IN input, C inputClass, E origin)	This method is called before executing a step
protected void	doDebug(String message)	Manually send a debug message
protected void	doReject(IN input)	Reject a character
protected abstract C	getClass(IN input)	Determines the class for an input character.
E	getCurrentState()	Return the current state
protected abstract E	getLandingState(IN input, C inputClass)	Determines the initial state upon meeting the input character and class
StateCtx<E,C,IN>	getState(E token)	Get the state by token.
StateCtx<E,C,IN>	getState(E token, boolean autoCreate)	Get the state by token.
protected void	init()	Called at the constructor of state machine
boolean	isSuspended()	Return true if the machine is suspended
boolean	isTerminated()	Return true if the machine is stopped
protected void	onDebug(String message)	This method is call at certain situations when debug mode is on.
protected void	onReject(IN input)	This method is called when the machine rejects an input character
protected void	onReset()	This method is called at constructor and when reseting the machine.
protected void	onStart(IN input, C inputClass, E landing)	This method is called when the machine takes the first character.
protected void	onStop(boolean endOfInput)	This method is called when the machine stops
StateCtx<E,C,IN>	removeState(E token)	Remove the state by token.
void	run(IN input)	Feed the machine a single character
void	run(Iterator<IN> inputs)	Feed the machine a stream of characters
StateMachine<E,C,IN>	setDebugMode(boolean mode)	Set debug mode, where onDebug(String) is called at certain timing to assist user develop the state machine
StateCtx<E,C,IN>	setState(E token, StateCtx<E,C,IN> state)	Set the state by token
void	start(IN input)	Starts the machine with a single input character.
void	start(Iterator<IN> inputs)	Starts the machine with a stream of input characters.
protected void	suspend()	Suspend the machine
void	terminate()	Terminates the machine.

Methods inherited from class java.lang.Object

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

Field Detail

_states

protected final Map<E,StateCtx<E,C,IN>> _states

_current

protected E _current

_run

protected boolean _run

_step

protected int _step

_debug

protected boolean _debug

Constructor Detail

StateMachine

public StateMachine()

Construct a state machine

Method Detail

setDebugMode

public StateMachine<E,C,IN> setDebugMode(boolean mode)

Set debug mode, where onDebug(String) is called at certain timing to assist user develop the state machine

setState

public StateCtx<E,C,IN> setState(E token,
                                             StateCtx<E,C,IN> state)

Set the state by token

Returns:

the state

removeState

public StateCtx<E,C,IN> removeState(E token)

Remove the state by token.

Returns:

the removed state

getState

public StateCtx<E,C,IN> getState(E token)

Get the state by token. Automatically creates one if it does not exist.

getState

public StateCtx<E,C,IN> getState(E token,
                                             boolean autoCreate)

Get the state by token.

Parameters:

autoCreate - if true, automatically creates one if it does not exist.

init

protected void init()

Called at the constructor of state machine

getLandingState

protected abstract E getLandingState(IN input,
                                     C inputClass)

Determines the initial state upon meeting the input character and class

getClass

protected abstract C getClass(IN input)

Determines the class for an input character.

onReset

protected void onReset()

This method is called at constructor and when reseting the machine.

onStart

protected void onStart(IN input,
                       C inputClass,
                       E landing)

This method is called when the machine takes the first character.

beforeStep

protected void beforeStep(IN input,
                          C inputClass,
                          E origin)

This method is called before executing a step

afterStep

protected void afterStep(IN input,
                         C inputClass,
                         E origin,
                         E destination)

This method is called after executing a step

onStop

protected void onStop(boolean endOfInput)

This method is called when the machine stops

Parameters:

endOfInput - true if the machine stops due to end of input

onReject

protected void onReject(IN input)

This method is called when the machine rejects an input character

onDebug

protected void onDebug(String message)

This method is call at certain situations when debug mode is on.

See Also:

setDebugMode(boolean)

run

public final void run(Iterator<IN> inputs)

Feed the machine a stream of characters

run

public final void run(IN input)

Feed the machine a single character

start

public final void start(Iterator<IN> inputs)

Starts the machine with a stream of input characters.

start

public final void start(IN input)

Starts the machine with a single input character.

terminate

public final void terminate()

Terminates the machine.

getCurrentState

public E getCurrentState()

Return the current state

isTerminated

public boolean isTerminated()

Return true if the machine is stopped

isSuspended

public boolean isSuspended()

Return true if the machine is suspended

suspend

protected final void suspend()

Suspend the machine

doReject

protected final void doReject(IN input)

Reject a character

doDebug

protected final void doDebug(String message)

Manually send a debug message

See Also:

onDebug(String), setDebugMode(boolean)