Package fsm allows you to add finite-state machines to your Go code.
States and Events are defined as int consts:
const (
StateFoo fsm.State = iota
StateBar
)
const (
EventFoo fsm.Event = iota
EventBar
)
f := fsm.New(StateFoo)
f.Transition(
fsm.On(EventFoo), fsm.Src(StateFoo),
fsm.Dst(StateBar),
)You can have custom checks or actions:
f.Transition(
fsm.Src(StateFoo), fsm.Check(func () bool {
// check something
}),
fsm.Call(func () {
// do something
}),
)Transitions can be triggered the second time an event occurs:
f.Transition(
fsm.On(EventFoo), fsm.Src(StateFoo), fsm.Times(2),
fsm.Dst(StateBar),
)Functions can be called when entering or leaving a state:
f.EnterState(StateFoo, func() {
// do something
})
f.Enter(func(state fsm.State) {
// do something
})
f.ExitState(StateFoo, func() {
// do something
})
f.Exit(func(state fsm.State) {
// do something
})This package is much faster and does a lot less allocations than github.com/looplab/fsm:
BenchmarkCocoonSpaceFSM-12 29371851 40.32 ns/op 0 B/op 0 allocs/op
BenchmarkLooplabFSM-12 2438946 487.8 ns/op 320 B/op 4 allocs/op
(benchmark data is for two executed transitions)
Benchmark information on https://github.com/cocoonspace/fsm-bench
go get github.com/cocoonspace/fsm
Contributions are welcome, as long as:
- unit tests & comments are included,
- no external package is used.
MIT - See LICENSE