lazy_list_test.m

%-----------------------------------------------------------------------------%
%
% lazy_list_test.m:
%    This is a trivial example of the use of lazy lists.
%
% This source file is hereby placed in the public domain.  -fjh (the author).

:- module lazy_list_test.
:- interface.
:- import_module io.

:- pred main(io::di, io::uo) is det.

%-----------------------------------------------------------------------------%

:- implementation.
:- import_module lazy, lazy_list, int.

:- func double(int) = int.
double(X) = 2 * X.

main -->
    { L = iterate(double, 1) },    % construct an infinite list...
    { L10 = take(10, L) },        % extract the first 10 elements
    print(to_list(L10)), nl.    % print them

%-----------------------------------------------------------------------------%