# README
go-fsm
It is a lightweight finite state machine (FSM) implementation in Golang. It has been inspired by the FSM used in Apache Hadoop YARN:
- Thread safe
- Multiple destination states
- Dynamic destination state determination
Installation
go get github.com/zjshen14/go-fsm
Usage
package main
import (
"fmt"
"github.com/zjshen14/go-fsm"
)
type evt struct {
t fsm.EventType
}
func (e *evt) Type() fsm.EventType { return e.t }
func main() {
fsm, _ := fsm.NewBuilder().
AddInitialState("s1").
AddStates("s2", "s3").
AddTransition("s1", "e1", func(event fsm.Event) (fsm.State, error) { return "s2", nil }, []fsm.State{"s2"}).
AddTransition("s2", "e2", func(event fsm.Event) (fsm.State, error) { return "s3", nil }, []fsm.State{"s3"}).
AddTransition("s3", "e3", func(event fsm.Event) (fsm.State, error) { return "s1", nil }, []fsm.State{"s1"}).
Build()
fmt.Println(fsm.CurrentState())
fsm.Handle(&evt{t: "e1"})
fmt.Println(fsm.CurrentState())
fsm.Handle(&evt{t: "e2"})
fmt.Println(fsm.CurrentState())
fsm.Handle(&evt{t: "e3"})
fmt.Println(fsm.CurrentState())
}
License
go-fsm is under the Apache 2.0 license. See the LICENSE file for details.
# Packages
No description provided by the author
# Functions
NewBuilder creates an FSM builder instance with empty setup.
# Variables
ErrBuild represents the error of building an FSM.
ErrInvalidTransition indicates that the actual destination state after transition is not defined.
ErrTransitionNotFound indicates that there doesn't exist a transition defined on the source state and the event.
# Type aliases
EventType represents a event type and it is a string.
State represents the state and it is a string.
Transition is the interface of the transition that would happen on a certain state when receiving a certain event.