Library for creating finite state machines allows defining states, transitions, and conditions for state changes. Includes sample applications like a dungeon explorer and a stopwatch, supporting various platforms.
Kotlin library for creating finite state machines.
It is an abstract machine that can be in exactly one of a finite number of states at any given time. The FSM can change from one state to another in response to some external inputs; the change from one state to another is called a transition. An FSM is defined by a list of its states, its initial state, and the conditions for each transition.
— Wikipedia - Finite-state machine
sealed class Energy {
object Kinetic : Energy()
Potential : Energy()
}
{
Store : EnergyTransition()
Release : EnergyTransition()
}
stateMachine = StateMachine(
Potential,
Potential onEvent Release:: ,
:
)
machine.state
machine.transition(Release)
Samples intend to show various ways the library might be used.
Kfin is now a Kotlin Multiplatform project supporting js, jvm, and jvmRx platforms.
kfin - includes base state machine implementation
compile "com.ToxicBakery.kfinstatemachine:kfin-<platform>:4.+"
Graph - includes directed graph implementation which can be used to create large state machines more easily
compile "com.ToxicBakery.kfinstatemachine:graph-<platform>:4.+"
The library depends on gradle for compilation and requires JDK 8 or higher.
./gradlew build
This library originally took a classical approach using a directed graph for state and callbacks for listening to state and transition changes. Thanks to a talk given by Ray Ryan from Square, I created an implementation generally following their state machine API and reworked my examples to fit. The exact slide can be found here and the talk in its whole is worth the watch.
Surfaced from shared tags and platforms — no rankings paid for.