%---------------------------------------------------------------------------%
% vim: ts=4 sw=4 et ft=mercury
%---------------------------------------------------------------------------%
%
% Regression test:
%
% This program uses a higher order function. Due to the way higher order
% types are represented as terms (which is quite different from any
% other type) manipulations of types that don't take this into account
% would make mistakes.
%
% The Mercury compiler of 20 December, 1996 failed to compile this,
% giving link errors.
%

:- module ho_func_reg.

:- interface.

:- import_module int.
:- import_module io.

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

:- type bar == (func(int) = int).
:- inst bar == (func(in) = out is det).

:- func foo(bar, int) = int.
:- mode foo(in(bar), in) = out is det.

:- func next(int) = int.

:- implementation.

main(!IO) :-
    io.write_string("I seem to have compiled ok.\n", !IO),
    Eight = foo(next, 7),
    io.write_int(Eight, !IO),
    io.write_string(" seems to be the answer\n", !IO).

next(I) = I + 1.

foo(F, I) = apply(F, I).