Split list

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That would be a concatenation in reverse order, though. A difference list can be used to “append” in the intended order.

Here is the same split implemented as a DCG, with basically the same performance as split_list_into_lens/3 (the cut increases performance):

% For string//1 at https://www.swi-prolog.org/pldoc/man?section=basics
:- use_module(library(dcg/basics)).

split_list(Len, Lst, LstSplit) :-
    must_be(positive_integer, Len),
    phrase(split(LstSplit, Len), Lst).

split([H|T], Len) --> split1(H, Len), !, split(T, Len).
% Terminate at end of list
split([], _) --> [].

% Grab list of intended length
split1(L, Len) --> { length(L, Len) }, string(L).
% ... or what remains at the end
split1(L, _Len) --> [L].

?- split_list(3, [a, b, c, d, e, f, g, h, i, j, k], Lsts).
Lsts = [[a,b,c],[d,e,f],[g,h,i],j,k].
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