Is this a good implementation of a loop in Prolog?
- by Carles Araguz
First of all, let me tell you that this happens to be the first time I ask something here, so if it's not the right place to do so, please forgive me.
I'm developing a rather complex software that has a Prolog core implementing a FSM. Since I don't want it to stop (ever), I'm trying to write a good loop-like predicate that would work using Prolog's recursion. After a few unsuccessful tries (mainly because of stack problems) I ended up having something similar to this:
/* Finite State Transition Network */
transition(st0,evnt0,st1).
transition(st1,evnt1,st2).
transition(st2,evnt2,st0).
fsm_state(state(st0),system(Energy,ActivePayloads),[]) :-
/* ... */
transition(st0,evnt0,NextState),
!,
fsm_state(state(NextState),system(Energy,ActivePayloads),[]).
fsm_state(state(st1),system(Energy,ActivePayloads),[]) :-
/* ... */
transition(st1,evnt1,NextState),
!,
fsm_state(state(NextState),system(Energy,ActivePayloads),[0,1,2]).
fsm_state(state(st2),system(Energy,ActivePayloads),[P|Params]) :-
/* ... */
transition(st2,evnt2,NextState),
!,
fsm_state(state(NextState),system(Energy,ActivePayloads),[]).
start :-
Sys = system(10,[]),
fsm_state(state(s0),Sys,[]).
Is this a good approach?
