%%% -*- erlang-indent-level: 2 -*-
%%%---------------------------------------------------------------------
%%% Author: Kostis Sagonas
%%%
%%% Contains tests cases for compilation of arithmetic.
%%%---------------------------------------------------------------------
-module(basic_arith).
-export([test/0]).
test() ->
ok = test_rem(),
ok = test_bit_ops(),
ok = test_uplus(),
ok = test_bsl_errors(),
ok.
%%----------------------------------------------------------------------
%% Tests the remainder operator.
test_rem() ->
2 = ret_rem(42, 20),
-2 = ret_rem(-42, 20),
-2 = ret_rem(-42, -20),
{'EXIT', {badarith, _}} = ret_rem(3.14, 2),
{'EXIT', {badarith, _}} = ret_rem(42, 3.14),
ok.
ret_rem(X, Y) ->
catch X rem Y.
%%----------------------------------------------------------------------
%%
test_bit_ops() ->
2 = bbb(11, 2, 16#3ff),
ok.
bbb(X, Y, Z) ->
((1 bsl X) bor Y) band Z.
%%----------------------------------------------------------------------
%% Tests unary plus: it used to be the identity function but not anymore
test_uplus() ->
badarith = try uplus(gazonk) catch error:Err -> Err end,
42 = uplus(42),
ok.
uplus(X) -> +(X).
%%----------------------------------------------------------------------
%% The first part of this test triggered a bug in the emulator as one
%% of the arguments to bsl is not an integer.
%%
%% The second part triggered a compilation crash since an arithmetic
%% expression resulting in a 'system_limit' exception was statically
%% evaluated and an arithmetic result was expected.
test_bsl_errors() ->
{'EXIT', {'badarith', _}} = (catch (t1(0, pad, 0))),
badarith = try t2(0, pad, 0) catch error:Err1 -> Err1 end,
system_limit = try (id(1) bsl 100000000) catch error:Err2 -> Err2 end,
ok.
t1(_, X, _) ->
(1 bsl X) + 1.
t2(_, X, _) ->
(X bsl 1) + 1.
id(I) -> I.
