Search code examples
parsingprologvisual-prolog

separate number into digit into prolog

I want to separate number into list digits using prolog

like :
     if number is "345"
separate to [3, 4, 5]

How can i do that ?

stringTokenizer("", []) :- !.
stringTokenizer(Sen, [H|T]) :-
   frontToken(Sen, Token, Remd), H = Token, stringTokenizer(Remd, T).

I am using this predicate to convert string into list of strings

Solution

  • Since there's no explicit answer, you can use the fact that strings are lists of ascii integers to simplify this, as was suggested by @RayToal. Just ensure that all the characters in the string are actually integers.

    stringTokenizer([], []).
stringTokenizer([N|Ns], [Digit|Rest]):-
    48 =< N, N =< 57,
    Digit is N - 48,
    stringTokenizer(Ns, Rest).

    Your example:

    ?- stringTokenizer("345", List).
List = [3, 4, 5].