-module(guards).
-compile([export_all]).
-record(r, {f}).
%% This is the reduced original test (no warnings)
-define(g1(A), ((A#r.f =:= a) orelse (A#r.f =:= b))).
t1(A) when ?g1(A) -> ok;
t1(A) when not ?g1(A) -> ko.
%% This should emit a warning
t1_s(A) when ?g1(A) -> ok.
t1_s_a() ->
t1_s(#r{f=c}).
%% Same as t1 with 'or' instead of 'orelse' (no warnings)
-define(g2(A), ((A#r.f =:= a) or (A#r.f =:= b))).
t2(A) when ?g2(A) -> ok;
t2(A) when not ?g2(A) -> ko.
%% This should emit a warning
t2_s(A) when ?g2(A) -> ok.
t2_s_a() ->
t2_s(#r{f=c}).
%% This could probably give a warning
-define(g3(A), (A#r.f =:= a orelse is_atom(A))).
t3(A) when ?g3(A) -> ok;
t3(A) when not ?g3(A) -> ko.
%% This could probably give a warning as well
-define(g4(A), ((A#r.f =:= a) or is_atom(A))).
t4(A) when ?g4(A) -> ok;
t4(A) when not ?g4(A) -> ko.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% Some shots in the dark on guard abuse %%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% Should give a warning
t5(A) when is_atom(A) and is_integer(A) -> never.
%% Should give the same warning as t5
t6(A) when is_atom(A) andalso is_integer(A) -> never.
%% Should give a warning
t7(A) when is_atom(A) or is_integer(A) -> ok.
at7(42) -> t7(42);
at7('a') -> t7('a');
at7({42}) -> t7({42}).
%% Should give a warning
t8(A) when is_atom(A) orelse is_integer(A) -> ok.
at8(42) -> t8(42);
at8('a') -> t8('a');
at8({42}) -> t8({42}).
%% Should give a warning
t9(A) when is_atom(A) orelse is_integer(A) -> ok;
t9(A) when is_atom(A) -> redundant.
%% Should give a warning
t10(A) when is_atom(A) or is_integer(A) -> ok;
t10(A) when is_atom(A) -> redundant.
%% Should give a warning
t11(A, B) when is_atom(A) and is_atom(B) ->
case {is_atom(A), is_atom(B)} of
{true, true} -> ok;
_ -> redundant
end.
%% Should give a warning
t12(A, B) when is_atom(A) andalso is_atom(B) ->
case {is_atom(A), is_atom(B)} of
{true, true} -> ok;
_ -> redundant
end.
%% Should give two warnings
t13(A, B) when is_atom(A) or is_atom(B) ->
case {is_atom(A), is_atom(B)} of
{true , true } -> ok;
{true , false} -> ok;
{false, true } -> ok;
{false, false} -> never;
{_ , _ } -> even_more_never
end.
%% Should give two warnings
t14(A, B) when is_atom(A) orelse is_atom(B) ->
case {is_atom(A), is_atom(B)} of
{true , true } -> ok;
{true , false} -> ok;
{false, true } -> ok;
{false, false} -> never;
{_ , _ } -> even_more_never
end.
%% Should give two warnings
t15(A) when ((A =:= a) or (A =:= b)) and ((A =:= b) or (A =:= c)) -> ok.
t15_a() -> t15(a), t15(b), t15(c).
%% Should give two warnings
t16(A) when ((A =:= a) orelse (A =:= b)) andalso
((A =:= b) orelse (A =:= c)) -> ok.
t16_a() -> t16(a), t16(b), t16(c).
