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%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 2001-2021. All Rights Reserved.
%%
%% Licensed under the Apache License, Version 2.0 (the "License");
%% you may not use this file except in compliance with the License.
%% You may obtain a copy of the License at
%%
%% http://www.apache.org/licenses/LICENSE-2.0
%%
%% Unless required by applicable law or agreed to in writing, software
%% distributed under the License is distributed on an "AS IS" BASIS,
%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
%% See the License for the specific language governing permissions and
%% limitations under the License.
%%
%% %CopyrightEnd%
%%
-module(lc_SUITE).
-export([all/0, suite/0, groups/0, init_per_suite/1, end_per_suite/1,
init_per_group/2,end_per_group/2,
init_per_testcase/2,end_per_testcase/2,
basic/1,deeply_nested/1,no_generator/1,
empty_generator/1,no_export/1,shadow/1,
effect/1]).
-include_lib("common_test/include/ct.hrl").
suite() ->
[{ct_hooks,[ts_install_cth]},
{timetrap,{minutes,1}}].
all() ->
[{group,p}].
groups() ->
[{p,test_lib:parallel(),
[basic,
deeply_nested,
no_generator,
empty_generator,
no_export,
shadow,
effect
]}].
init_per_suite(Config) ->
test_lib:recompile(?MODULE),
Config.
end_per_suite(_Config) ->
ok.
init_per_group(_GroupName, Config) ->
Config.
end_per_group(_GroupName, Config) ->
Config.
init_per_testcase(Case, Config) when is_atom(Case), is_list(Config) ->
Config.
end_per_testcase(Case, Config) when is_atom(Case), is_list(Config) ->
ok.
basic(Config) when is_list(Config) ->
L0 = lists:seq(1, 10),
L1 = my_map(fun(X) -> {x,X} end, L0),
L1 = [{x,X} || X <- L0],
L0 = my_map(fun({x,X}) -> X end, L1),
[1,2,3,4,5] = [X || X <- L0, X < 6],
[4,5,6] = [X || X <- L0, X > 3, X < 7],
[] = [X || X <- L0, X > 32, X < 7],
[1,3,5,7,9] = [X || X <- L0, odd(X)],
[2,4,6,8,10] = [X || X <- L0, not odd(X)],
[1,3,5,9] = [X || X <- L0, odd(X), X =/= 7],
[2,4,8,10] = [X || X <- L0, not odd(X), X =/= 6],
%% Append is specially handled.
[1,3,5,9,2,4,8,10] = [X || X <- L0, odd(X), X =/= 7] ++
[X || X <- L0, not odd(X), X =/= 6],
%% Guards BIFs are evaluated in guard context. Weird, but true.
[{a,b,true},{x,y,true,true}] = [X || X <- tuple_list(), element(3, X)],
%% Filter expressions with andalso/orelse.
"abc123" = alphanum("?abc123.;"),
%% Aliased patterns.
[] = [t || {C=D}={_,_} <- []],
[] = [X || {X,{Y}={X,X}} <- []],
[t] = [t || "a"++"b" = "ab" <- ["ab"]],
%% Strange filter block.
[] = [{X,Y} || {X} <- [], begin Y = X, Y =:= X end],
[{a,a}] = [{X,Y} || {X} <- [{a}], begin Y = X, Y =:= X end],
%% Not matching.
[] = [3 || {3=4} <- []],
%% Error cases.
[] = [{xx,X} || X <- L0, element(2, X) == no_no_no],
{'EXIT',_} = (catch [X || X <- L1, list_to_atom(X) == dum]),
[] = [X || X <- L1, X+1 < 2],
{'EXIT',_} = (catch [X || X <- L1, odd(X)]),
{'EXIT',{{bad_generator,x},_}} = (catch [E || E <- id(x)]),
{'EXIT',{{bad_filter,not_bool},_}} = (catch [E || E <- [1,2], id(not_bool)]),
%% Make sure that line numbers point out the generator.
case ?MODULE of
lc_inline_SUITE ->
ok;
_ ->
{'EXIT',{{bad_generator,a},
[{?MODULE,_,_,
[{file,"bad_lc.erl"},{line,4}]}|_]}} =
(catch id(bad_generator(a))),
{'EXIT',{{bad_generator,a},
[{?MODULE,_,_,
[{file,"bad_lc.erl"},{line,7}]}|_]}} =
(catch id(bad_generator_bc(a))),
%% List comprehensions with improper lists.
{'EXIT',{{bad_generator,d},
[{?MODULE,_,_,
[{file,"bad_lc.erl"},{line,4}]}|_]}} =
(catch bad_generator(id([a,b,c|d])))
end,
ok.
tuple_list() ->
[{a,b,true},[a,b,c],glurf,{a,b,false,xx},{a,b},{x,y,true,true},{a,b,d,ddd}].
my_map(F, L) ->
[F(X) || X <- L].
odd(X) ->
X rem 2 == 1.
alphanum(Str) ->
[C || C <- Str, ((C >= $0) andalso (C =< $9))
orelse ((C >= $a) andalso (C =< $z))
orelse ((C >= $A) andalso (C =< $Z))].
deeply_nested(Config) when is_list(Config) ->
[[99,98,97,96,42,17,1764,12,11,10,9,8,7,6,5,4,3,7,2,1]] = deeply_nested_1(),
ok.
deeply_nested_1() ->
%% This used to compile really, really SLOW before R11B-1...
[[X1,X2,X3,X4,X5,X6,X7(),X8,X9,X10,X11,X12,X13,X14,X15,X16,X17,X18(),X19,X20] ||
X1 <- [99],X2 <- [98],X3 <- [97],X4 <- [96],X5 <- [42],X6 <- [17],
X7 <- [fun() -> X5*X5 end],X8 <- [12],X9 <- [11],X10 <- [10],
X11 <- [9],X12 <- [8],X13 <- [7],X14 <- [6],X15 <- [5],
X16 <- [4],X17 <- [3],X18 <- [fun() -> X16+X17 end],X19 <- [2],X20 <- [1]].
no_generator(Config) when is_list(Config) ->
Seq = lists:seq(-10, 17),
[no_gen_verify(no_gen(A, B), A, B) || A <- Seq, B <- Seq],
%% Literal expression, for coverage.
[a] = [a || true],
[a,b,c] = [a || true] ++ [b,c],
ok.
no_gen(A, B) ->
[{A,B} || A+B =:= 0] ++
[{A,B} || A*B =:= 0] ++
[{A,B} || A rem B =:= 3] ++
[{A,B} || A =:= B] ++
[{one_more,A,B} || no_gen_one_more(A, B)] ++
[A || A =:= 1] ++
[A || A =:= 2] ++
[A || A =:= 3] ++
[A || A =:= 4] ++
[A || A =:= 5] ++
[A || A =:= 6] ++
[A || A =:= 7] ++
[A || A =:= 8] ++
[A || A =:= 9] ++
[B || B =:= 1] ++
[B || B =:= 2] ++
[B || B =:= 3] ++
[B || B =:= 4] ++
[B || B =:= 5] ++
[B || B =:= 6] ++
[B || B =:= 7] ++
[B || B =:= 8] ++
[B || B =:= 9].
no_gen_verify(Res, A, B) ->
Pair = {A,B},
ShouldBe = no_gen_eval(fun() -> A+B =:= 0 end, Pair) ++
no_gen_eval(fun() -> A*B =:= 0 end, Pair) ++
no_gen_eval(fun() -> B =/= 0 andalso A rem B =:= 3 end, Pair) ++
no_gen_eval(fun() -> A =:= B end, Pair) ++
no_gen_eval(fun() -> A + 1 =:= B end, {one_more,A,B}) ++
no_gen_eval(fun() -> 1 =< A andalso A =< 9 end, A) ++
no_gen_eval(fun() -> 1 =< B andalso B =< 9 end, B),
case Res of
ShouldBe -> ok;
_ ->
io:format("A = ~p; B = ~p; Expected = ~p, actual = ~p", [A,B,ShouldBe,Res]),
ct:fail(failed)
end.
no_gen_eval(Fun, Res) ->
case Fun() of
true -> [Res];
false -> []
end.
no_gen_one_more(A, B) -> A + 1 =:= B.
empty_generator(Config) when is_list(Config) ->
[] = [X || {X} <- [], (false or (X/0 > 3))],
ok.
no_export(Config) when is_list(Config) ->
[] = [ _X = a || false ] ++ [ _X = a || false ],
ok.
%% Test that variables in list comprehensions are
%% correctly shadowed.
shadow(Config) when is_list(Config) ->
Shadowed = nomatch,
_ = id(Shadowed), %Eliminate warning.
L = [{Shadowed,Shadowed+1} || Shadowed <- lists:seq(7, 9)],
[{7,8},{8,9},{9,10}] = id(L),
[8,9] = id([Shadowed || {_,Shadowed} <- id(L),
Shadowed < 10]),
ok.
effect(Config) when is_list(Config) ->
ct:timetrap({minutes,10}),
[{42,{a,b,c}}] =
do_effect(fun(F, L) ->
[F({V1,V2}) ||
#{<<1:500>>:=V1,<<2:301>>:=V2} <- L],
ok
end, id([#{},x,#{<<1:500>>=>42,<<2:301>>=>{a,b,c}}])),
%% Will trigger the time-trap timeout if not tail-recursive.
case ?MODULE of
lc_SUITE ->
_ = [{'EXIT',{badarg,_}} =
(catch binary_to_atom(<<C/utf8>>, utf8)) ||
C <- lists:seq(16#FF10000, 16#FFFFFFF)];
_ ->
ok
end,
ok.
do_effect(Lc, L) ->
put(?MODULE, []),
F = fun(V) -> put(?MODULE, [V|get(?MODULE)]) end,
ok = Lc(F, L),
lists:reverse(erase(?MODULE)).
id(I) -> I.
-file("bad_lc.erl", 1).
bad_generator(List) -> %Line 2
[I || %Line 3
I <- List]. %Line 4
bad_generator_bc(List) -> %Line 5
<< <<I:4>> || %Line 6
I <- List>>. %Line 7
|
