[erlang-questions] join/2 function
Sun Dec 17 09:39:36 CET 2006
Hoan Ton-That writes:
> I think that the following function join should
> be included in the lists module.
> join(Sep, List) ->
> lists:foldl(fun(A, "") -> A; (A, Acc) -> Acc ++ Sep ++ A end, "", List).
Your implementation of join is quadratic in the length of the list.
Here's one O(N) way to do it:
lcjoin(Sep, [H|T]) ->
Joined = [ [Sep|X] || X <- T ],
In many cases the lists:flatten/1 call is unnecessary.
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