Re: "ocaml_beginners"::[] reverse a list. is this a good solution

Le 2014-10-20 12:56, Roelof Wobben [email protected] [ocaml_beginners] a 
écrit :
> Hello,
> 
>  I try the 99 ocaml problems and have solved the reverse a list
> problem.
> 
>  My solution looks like this :
> 
>  let rec test l1 l2 =
>  match l1 with
>  | [] -> l2
>  | h :: t -> test t (h::l2)
>  ;;
> 
>  Is this a good way to solve it or are there things that can be better
> ?
> 

This is a good way :) You've written a tail recursive function[1] !

[1] https://en.wikipedia.org/wiki/Tail_call

But this is not yet finished : your function takes 2 arguments, and you 
expect the second to be an empty list.

What will happen if someone call your function like this ?

> test [ "a" ; "b" ; "c"] [ "1" ; "2" ; "3"];;

Is there a way to « hide » your algorithm, and get a function which 
takes only one list ? (Hint : you can wrap a function inside another 
one…)

-- 
Sébastien