%%% -*- erlang-indent-level: 2 -*-
%%%-------------------------------------------------------------------
%%% Author: Kostis Sagonas
%%%
%%% Tests for correct handling of funs.
%%%-------------------------------------------------------------------
-module(basic_fun).
-export([test/0]).
-export([dummy_foo/4, add1/1, test_fun03/0]).
test() ->
ok = test_calls(),
ok = test_is_function(),
ok = test_is_function2(),
ok.
%%--------------------------------------------------------------------
%% Tests function and fun calls.
test_calls() ->
ok = test_apply_call(?MODULE, dummy_foo),
ok = test_fun_call(fun dummy_foo/4),
ok = test_fun_call(fun ?MODULE:dummy_foo/4),
ok.
test_apply_call(M, F) ->
M:F(bar, 42, foo, 17).
test_fun_call(Fun) ->
Fun(bar, 42, foo, 17).
dummy_foo(_, _, foo, _) -> ok.
%%--------------------------------------------------------------------
%% Tests handling of funs out of exported functions and 2-tuple funs.
test_fun03() ->
MFPair = add1_as_2tuple(),
4712 = do_call(add1_as_export(), 4711),
{badfun, MFPair} = try do_call(MFPair, 88) catch error:Err -> Err end,
true = do_guard(add1_as_export()),
false = do_guard(MFPair), % 2-tuples do not satisfy is_function/1
ok.
do_call(F, X) -> F(X).
do_guard(F) when is_function(F) -> true;
do_guard(_) -> false.
add1_as_export() -> fun ?MODULE:add1/1.
add1_as_2tuple() -> {?MODULE, add1}.
add1(X) -> X+1.
%%--------------------------------------------------------------------
%% Tests the is_function guard and BIF.
test_is_function() ->
Fun = fun (X, foo) -> dummy_foo(X, mnesia_lib, foo, [X]) end,
ok = test_when_guard(Fun),
ok = test_if_guard(Fun),
ok.
test_when_guard(X) when is_function(X) -> ok.
test_if_guard(X) ->
if is_function(X) -> ok;
true -> weird
end.
%%--------------------------------------------------------------------
%% Tests the is_function2 guard and BIF.
test_is_function2() ->
ok = test_guard(),
ok = test_guard2(),
ok = test_call(),
ok.
test_guard() ->
zero_fun = test_f2(fun () -> ok end),
unary_fun = test_f2(fun(X) -> X end),
binary_fun = test_f2(fun (X, Y) -> {X, Y} end),
no_fun = test_f2(gazonk),
ok.
test_f2(Fun) when is_function(Fun, 0) ->
zero_fun;
test_f2(Fun) when is_function(Fun, 1) ->
unary_fun;
test_f2(Fun) when is_function(Fun, 2) ->
binary_fun;
test_f2(_) ->
no_fun.
test_guard2() ->
zero_fun = test_f2_n(fun () -> ok end, 0),
unary_fun = test_f2_n(fun (X) -> X end, 1),
binary_fun = test_f2_n(fun (X, Y) -> {X, Y} end, 2),
no_fun = test_f2_n(gazonk, 0),
ok.
test_f2_n(F, N) when is_function(F, N) ->
case N of
0 -> zero_fun;
1 -> unary_fun;
2 -> binary_fun
end;
test_f2_n(_, _) ->
no_fun.
test_call() ->
true = test_fn2(fun (X, Y) -> {X,Y} end, 2),
false = test_fn2(fun (X, Y) -> {X,Y} end, 3),
false = test_fn2(gazonk, 2),
{'EXIT', {badarg, _TR1}} = (catch test_fn2(gazonk, gazonk)),
{'EXIT', {badarg, _TR2}} = (catch test_fn2(fun (X, Y) -> {X, Y} end, gazonk)),
ok.
test_fn2(F, N) ->
is_function(F, N).
