-module(abs).
%% OTP-12948. erlang:abs/1 bug fix.
-export([t/0]).
t() ->
Fs = [fun i1/0, fun i2/0, fun i3/0, fun i4/0, fun f1/0, fun erl_551/0],
_ = [catch F() || F <- Fs],
ok.
i1() ->
A = int(),
I1 = i1(A),
true = I1 < 2,
true = I1 < 1. % can never match
-spec i1(neg_integer()) -> non_neg_integer().
i1(A) when is_integer(A), A < 0 ->
abs(A).
i2() ->
A = int(),
I2 = i2(A),
true = I2 < 1,
true = I2 < 0. % can never match
-spec i2(non_neg_integer()) -> non_neg_integer().
i2(A) when is_integer(A), A >= 0 ->
abs(A).
i3() ->
A = int(),
I3 = i3(A),
true = I3 < -1,
true = I3 < 0. % can never match
-spec i3(integer()) -> non_neg_integer().
i3(A) when is_integer(A) ->
abs(A).
i4() ->
A = int(),
I4 = i4(A),
true = I4 =:= 0 orelse I4 =:= 1,
true = I4 < 0 orelse I4 > 1. % can never match
-spec i4(integer()) -> number().
i4(A) when A =:= -1; A =:= 0; A =:= 1 ->
abs(A).
f1() ->
F1 = f1(float()),
math:sqrt(F1).
f1(A) ->
abs(A).
erl_551() ->
accept(9),
accept(-3).
accept(Number) when abs(Number) >= 8 -> first;
accept(_Number) -> second.
-spec int() -> integer().
int() ->
foo:bar().
-spec float() -> float().
float() ->
math:sqrt(1.0).
