Should I avoid tail recursion in Prolog and in general?

Question

I\'m working through \"Learn Prolog now\" online book for fun.

I\'m trying to write a predicate that goes through each member of a list and adds one to it, using acc

Answer 1

Your addOne procedure already is tail recursive.

There are no choice points between the head and the last recursive call, because is/2 is deterministic.

Accumulators are sometime added to allow tail recursion, the simpler example I can think of is reverse/2. Here is a naive reverse (nreverse/2), non tail recursive

nreverse([], []).
nreverse([X|Xs], R) :- nreverse(Xs, Rs), append(Rs, [X], R).

if we add an accumulator

reverse(L, R) :- reverse(L, [], R).
reverse([], R, R).
reverse([X|Xs], A, R) :- reverse(Xs, [X|A], R).

now reverse/3 is tail recursive: the recursive call is the last one, and no choice point is left.