v/vlib/statemachine/statemachine.v

67 lines
1.4 KiB
V

module statemachine
pub type EventHandlerFn = fn (receiver voidptr)
pub type ConditionFn = fn (receiver voidptr) bool
struct State {
mut:
entry_handler EventHandlerFn
run_handler EventHandlerFn
exit_handler EventHandlerFn
}
struct Transition {
mut:
to string
condition ConditionFn
}
struct StateMachine {
mut:
states map[string]State
transitions map[string]Transition
current_state string
}
pub fn new() &StateMachine {
return &StateMachine{}
}
pub fn (mut s StateMachine) add_state(name string, entry EventHandlerFn, run EventHandlerFn, exit EventHandlerFn) {
s.states[name] = State{
entry_handler: entry
run_handler: run
exit_handler: exit
}
if s.states.len == 1 {
s.current_state = name
}
}
pub fn (mut s StateMachine) add_transition(from string, to string, condition ConditionFn) {
s.transitions[from] = Transition{
to: to
condition: condition
}
}
pub fn (mut s StateMachine) run(receiver voidptr) {
for from_state, transition in s.transitions {
if from_state == s.current_state {
if transition.condition(receiver) {
s.change_state(receiver, s.transitions[from_state].to)
}
s.states[s.current_state].run_handler(receiver)
}
}
}
pub fn (mut s StateMachine) change_state(receiver voidptr, newstate string) {
mut current_state := s.current_state
s.states[current_state].exit_handler(receiver)
current_state = newstate
s.states[current_state].entry_handler(receiver)
s.current_state = current_state
}