transform.go

package msm

import (
	"fmt"
	"reflect"
)

func eventType(event Event) reflect.Type {
	t := reflect.TypeOf(event)
	if t.Kind() == reflect.Ptr {
		return t
	} else {
		return reflect.PointerTo(t)
	}
}

func (f *FSM) newTransition(state State, event Event, newState State, action Action, guard Guard) Transition {
	eventType := eventType(event)

	rule := Transition{
		TransitionKey: TransitionKey{
			State: state,
			Event: eventType,
		},
		TransitionValue: TransitionValue{
			NewState: newState,
			Action:   action,
			Guard:    guard,
		},
	}

	// Validate Action
	aType := reflect.FuncOf([]reflect.Type{
		reflect.TypeOf(new(FSMInstance)),
		f.storageType,
		reflect.TypeOf(*new(State)),
		reflect.TypeOf(*new(string)),
		eventType,
	}, []reflect.Type{},
		false,
	)
	if reflect.ValueOf(action).Pointer() != reflect.ValueOf(NoAction).Pointer() && aType != reflect.TypeOf(action) {
		panic(fmt.Sprintf("Rule: %+v\nExpected action:\n'%v', Got:\n'%v'\n", rule, aType, reflect.TypeOf(action)))
	}

	// Validate Guard
	gType := reflect.FuncOf([]reflect.Type{
		reflect.TypeOf(new(FSMInstance)),
		f.storageType,
		reflect.TypeOf(*new(State)),
		reflect.TypeOf(*new(string)),
		eventType,
	}, []reflect.Type{
		reflect.TypeOf(*new(bool)),
	},
		false,
	)
	if reflect.ValueOf(guard).Pointer() != reflect.ValueOf(NoGuard).Pointer() && gType != reflect.TypeOf(guard) {
		panic(fmt.Sprintf("Rule: %+v\nExpected guard:\n'%v', Got:\n'%v'\n", rule, gType, reflect.TypeOf(guard)))
	}

	return rule
}

func (f *FSM) RowAG(state State, event Event, newState State, action Action, guard Guard) Transition {
	return f.newTransition(state, event, newState, action, guard)
}

func (f *FSM) RowA(state State, event Event, newState State, action Action) Transition {
	return f.newTransition(state, event, newState, action, NoGuard)
}

func (f *FSM) RowG(state State, event Event, newState State, guard Guard) Transition {
	return f.newTransition(state, event, newState, NoAction, guard)
}

func (f *FSM) Row(state State, event Event, newState State) Transition {
	return f.newTransition(state, event, newState, NoAction, NoGuard)
}