https://github.com/looplab/fsm

Finite State Machine for Go
https://github.com/looplab/fsm

finite-state-machine fsm go

Last synced: 11 days ago
JSON representation

Finite State Machine for Go

• Host: GitHub
• URL: https://github.com/looplab/fsm
• Owner: looplab
• License: apache-2.0
• Created: 2013-08-21T14:30:43.000Z (about 11 years ago)
• Default Branch: main
• Last Pushed: 2024-08-16T08:13:10.000Z (3 months ago)
• Last Synced: 2024-10-14T20:23:58.327Z (25 days ago)
• Topics: finite-state-machine, fsm, go
• Language: Go
• Size: 72.3 KB
• Stars: 2,827
• Watchers: 51
• Forks: 312
• Open Issues: 29
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

Awesome Lists containing this project

• awesome-repositories - looplab/fsm - Finite State Machine for Go (Go)
• awesome-go - FSM for Go - Finite State Machine (Data structures)
• go-awesome - FSM - finite state machine (Open source library / Algorithm)
• awesome-golang-repositories - fsm

README

        
[![PkgGoDev](https://pkg.go.dev/badge/github.com/looplab/fsm)](https://pkg.go.dev/github.com/looplab/fsm)

![Bulid Status](https://github.com/looplab/fsm/actions/workflows/main.yml/badge.svg)

[![Coverage Status](https://img.shields.io/coveralls/looplab/fsm.svg)](https://coveralls.io/r/looplab/fsm)

[![Go Report Card](https://goreportcard.com/badge/looplab/fsm)](https://goreportcard.com/report/looplab/fsm)

# FSM for Go

FSM is a finite state machine for Go.

It is heavily based on two FSM implementations:

- Javascript Finite State Machine, https://github.com/jakesgordon/javascript-state-machine

- Fysom for Python, https://github.com/oxplot/fysom (forked at https://github.com/mriehl/fysom)

For API docs and examples see http://godoc.org/github.com/looplab/fsm

# Basic Example

From examples/simple.go:

```go

package main

import (

    "context"

    "fmt"

    "github.com/looplab/fsm"

)

func main() {

    fsm := fsm.NewFSM(

        "closed",

        fsm.Events{

            {Name: "open", Src: []string{"closed"}, Dst: "open"},

            {Name: "close", Src: []string{"open"}, Dst: "closed"},

        },

        fsm.Callbacks{},

    )

    fmt.Println(fsm.Current())

    err := fsm.Event(context.Background(), "open")

    if err != nil {

        fmt.Println(err)

    }

    fmt.Println(fsm.Current())

    err = fsm.Event(context.Background(), "close")

    if err != nil {

        fmt.Println(err)

    }

    fmt.Println(fsm.Current())

}

```

# Usage as a struct field

From examples/struct.go:

```go

package main

import (

    "context"

    "fmt"

    "github.com/looplab/fsm"

)

type Door struct {

    To  string

    FSM *fsm.FSM

}

func NewDoor(to string) *Door {

    d := &Door{

        To: to,

    }

    d.FSM = fsm.NewFSM(

        "closed",

        fsm.Events{

            {Name: "open", Src: []string{"closed"}, Dst: "open"},

            {Name: "close", Src: []string{"open"}, Dst: "closed"},

        },

        fsm.Callbacks{

            "enter_state": func(_ context.Context, e *fsm.Event) { d.enterState(e) },

        },

    )

    return d

}

func (d *Door) enterState(e *fsm.Event) {

    fmt.Printf("The door to %s is %s\n", d.To, e.Dst)

}

func main() {

    door := NewDoor("heaven")

    err := door.FSM.Event(context.Background(), "open")

    if err != nil {

        fmt.Println(err)

    }

    err = door.FSM.Event(context.Background(), "close")

    if err != nil {

        fmt.Println(err)

    }

}

```

# License

FSM is licensed under Apache License 2.0

http://www.apache.org/licenses/LICENSE-2.0