raj457036 / simple_finite_state_machine

A Simple Finite State Machine

Features

• well, its simple to use

Getting started

# add the dependencies
simple_finite_state_machine:
  git: https://github.com/raj457036/simple_finite_state_machine.git

Usage

credit: https://github.com/Tinder/StateMachine

Below is a simple example based on above diagram

// states
class Solid extends MachineState<Solid> {
  @override
  get transitions => [Melt];
}

class Liquid extends MachineState<Liquid> {
  @override
  get transitions => [Vaporize, Freeze];
}

class Gas extends MachineState<Gas> {
  @override
  get transitions => [Condense];
}

// transitions
class Melt extends StateTransition<Solid> {
  @override
  MachineState? target(current) {
    return Liquid();
  }
}

class Vaporize extends StateTransition<Liquid> {
  @override
  MachineState? target(current) {
    return Gas();
  }
}

class Condense extends StateTransition<Gas> {
  @override
  MachineState? target(current) {
    return Liquid();
  }
}

class Freeze extends StateTransition<Liquid> {
  @override
  MachineState? target(current) {
    return Solid();
  }
}

// main program
void main(List<String> args) {
  final machine = Machine(Solid(), logging: true);

  machine.execute(Melt());
  machine.execute(Vaporize());
  machine.execute(Condense());
  machine.execute(Freeze());
  // This one will fail
  machine.execute(Condense());
}

Additional information

The example above is from Tinder State Machine Example