1%%
2%% %CopyrightBegin%
3%%
4%% Copyright Ericsson AB 2001-2018. All Rights Reserved.
5%%
6%% Licensed under the Apache License, Version 2.0 (the "License");
7%% you may not use this file except in compliance with the License.
8%% You may obtain a copy of the License at
9%%
10%%     http://www.apache.org/licenses/LICENSE-2.0
11%%
12%% Unless required by applicable law or agreed to in writing, software
13%% distributed under the License is distributed on an "AS IS" BASIS,
14%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15%% See the License for the specific language governing permissions and
16%% limitations under the License.
17%%
18%% %CopyrightEnd%
19%%
20-module(lc_SUITE).
21
22-export([all/0, suite/0, groups/0, init_per_suite/1, end_per_suite/1,
23	 init_per_group/2,end_per_group/2,
24	 init_per_testcase/2,end_per_testcase/2,
25	 basic/1,deeply_nested/1,no_generator/1,
26	 empty_generator/1,no_export/1,shadow/1,
27	 effect/1]).
28
29-include_lib("common_test/include/ct.hrl").
30
31suite() ->
32    [{ct_hooks,[ts_install_cth]},
33     {timetrap,{minutes,1}}].
34
35all() ->
36    [{group,p}].
37
38groups() ->
39    [{p,test_lib:parallel(),
40      [basic,
41       deeply_nested,
42       no_generator,
43       empty_generator,
44       no_export,
45       shadow,
46       effect
47      ]}].
48
49init_per_suite(Config) ->
50    test_lib:recompile(?MODULE),
51    Config.
52
53end_per_suite(_Config) ->
54    ok.
55
56init_per_group(_GroupName, Config) ->
57    Config.
58
59end_per_group(_GroupName, Config) ->
60    Config.
61
62
63init_per_testcase(Case, Config) when is_atom(Case), is_list(Config) ->
64    Config.
65
66end_per_testcase(Case, Config) when is_atom(Case), is_list(Config) ->
67    ok.
68
69basic(Config) when is_list(Config) ->
70    L0 = lists:seq(1, 10),
71    L1 = my_map(fun(X) -> {x,X} end, L0),
72    L1 = [{x,X} || X <- L0],
73    L0 = my_map(fun({x,X}) -> X end, L1),
74    [1,2,3,4,5] = [X || X <- L0, X < 6],
75    [4,5,6] = [X || X <- L0, X > 3, X < 7],
76    [] = [X || X <- L0, X > 32, X < 7],
77    [1,3,5,7,9] = [X || X <- L0, odd(X)],
78    [2,4,6,8,10] = [X || X <- L0, not odd(X)],
79    [1,3,5,9] = [X || X <- L0, odd(X), X =/= 7],
80    [2,4,8,10] = [X || X <- L0, not odd(X), X =/= 6],
81
82    %% Append is specially handled.
83    [1,3,5,9,2,4,8,10] = [X || X <- L0, odd(X), X =/= 7] ++
84	[X || X <- L0, not odd(X), X =/= 6],
85
86    %% Guards BIFs are evaluated in guard context. Weird, but true.
87    [{a,b,true},{x,y,true,true}] = [X || X <- tuple_list(), element(3, X)],
88
89    %% Filter expressions with andalso/orelse.
90    "abc123" = alphanum("?abc123.;"),
91
92    %% Aliased patterns.
93    [] = [t || {C=D}={_,_} <- []],
94    [] = [X || {X,{Y}={X,X}} <- []],
95    [t] = [t || "a"++"b" = "ab" <- ["ab"]],
96
97    %% Strange filter block.
98    [] = [{X,Y} || {X} <- [], begin Y = X, Y =:= X end],
99    [{a,a}] = [{X,Y} || {X} <- [{a}], begin Y = X, Y =:= X end],
100
101    %% Not matching.
102    [] = [3 || {3=4} <- []],
103
104    %% Error cases.
105    [] = [{xx,X} || X <- L0, element(2, X) == no_no_no],
106    {'EXIT',_} = (catch [X || X <- L1, list_to_atom(X) == dum]),
107    [] = [X || X <- L1, X+1 < 2],
108    {'EXIT',_} = (catch [X || X <- L1, odd(X)]),
109    fc([x], catch [E || E <- id(x)]),
110
111    %% Make sure that line numbers point out the generator.
112    case ?MODULE of
113        lc_inline_SUITE ->
114            ok;
115        _ ->
116            {'EXIT',{function_clause,
117                     [{?MODULE,_,_,
118                       [{file,"bad_lc.erl"},{line,4}]}|_]}} =
119                (catch bad_generator(a)),
120            {'EXIT',{function_clause,
121                     [{?MODULE,_,_,
122                       [{file,"bad_lc.erl"},{line,4}]}|_]}} =
123                (catch bad_generator([a|b])),
124            {'EXIT',{badarg,
125                     [{erlang,length,_,_},
126                      {?MODULE,bad_generator_bc,1,
127                       [{file,"bad_lc.erl"},{line,7}]}|_]}} =
128                (catch bad_generator_bc(a)),
129            {'EXIT',{badarg,
130                     [{erlang,length,_,_},
131                      {?MODULE,bad_generator_bc,1,
132                       [{file,"bad_lc.erl"},{line,7}]}|_]}} =
133                (catch bad_generator_bc([a|b]))
134    end,
135    ok.
136
137tuple_list() ->
138    [{a,b,true},[a,b,c],glurf,{a,b,false,xx},{a,b},{x,y,true,true},{a,b,d,ddd}].
139
140my_map(F, L) ->
141    [F(X) || X <- L].
142
143odd(X) ->
144    X rem 2 == 1.
145
146alphanum(Str) ->
147    [C || C <- Str, ((C >= $0) andalso (C =< $9))
148	      orelse ((C >= $a) andalso (C =< $z))
149	      orelse ((C >= $A) andalso (C =< $Z))].
150
151deeply_nested(Config) when is_list(Config) ->
152    [[99,98,97,96,42,17,1764,12,11,10,9,8,7,6,5,4,3,7,2,1]] =  deeply_nested_1(),
153    ok.
154
155deeply_nested_1() ->
156    %% This used to compile really, really SLOW before R11B-1...
157    [[X1,X2,X3,X4,X5,X6,X7(),X8,X9,X10,X11,X12,X13,X14,X15,X16,X17,X18(),X19,X20] ||
158        X1 <- [99],X2 <- [98],X3 <- [97],X4 <- [96],X5 <- [42],X6 <- [17],
159	X7 <- [fun() -> X5*X5 end],X8 <- [12],X9 <- [11],X10 <- [10],
160        X11 <- [9],X12 <- [8],X13 <- [7],X14 <- [6],X15 <- [5],
161	X16 <- [4],X17 <- [3],X18 <- [fun() -> X16+X17 end],X19 <- [2],X20 <- [1]].
162
163no_generator(Config) when is_list(Config) ->
164    Seq = lists:seq(-10, 17),
165    [no_gen_verify(no_gen(A, B), A, B) || A <- Seq, B <- Seq],
166
167    %% Literal expression, for coverage.
168    [a] = [a || true],
169    [a,b,c] = [a || true] ++ [b,c],
170    ok.
171
172no_gen(A, B) ->
173    [{A,B} || A+B =:= 0] ++
174	[{A,B} || A*B =:= 0] ++
175	[{A,B} || A rem B =:= 3] ++
176	[{A,B} || A =:= B] ++
177	[{one_more,A,B} || no_gen_one_more(A, B)] ++
178	[A || A =:= 1] ++
179	[A || A =:= 2] ++
180	[A || A =:= 3] ++
181	[A || A =:= 4] ++
182	[A || A =:= 5] ++
183	[A || A =:= 6] ++
184	[A || A =:= 7] ++
185	[A || A =:= 8] ++
186	[A || A =:= 9] ++
187	[B || B =:= 1] ++
188	[B || B =:= 2] ++
189	[B || B =:= 3] ++
190	[B || B =:= 4] ++
191	[B || B =:= 5] ++
192	[B || B =:= 6] ++
193	[B || B =:= 7] ++
194	[B || B =:= 8] ++
195	[B || B =:= 9].
196
197no_gen_verify(Res, A, B) ->
198    Pair = {A,B},
199    ShouldBe = no_gen_eval(fun() -> A+B =:= 0 end, Pair) ++
200	no_gen_eval(fun() -> A*B =:= 0 end, Pair) ++
201	no_gen_eval(fun() -> B =/= 0 andalso A rem B =:= 3 end, Pair) ++
202	no_gen_eval(fun() -> A =:= B end, Pair) ++
203	no_gen_eval(fun() -> A + 1 =:= B end, {one_more,A,B}) ++
204	no_gen_eval(fun() -> 1 =< A andalso A =< 9 end, A) ++
205	no_gen_eval(fun() -> 1 =< B andalso B =< 9 end, B),
206    case Res of
207	ShouldBe -> ok;
208	_ ->
209	    io:format("A = ~p; B = ~p; Expected = ~p, actual = ~p", [A,B,ShouldBe,Res]),
210	    ct:fail(failed)
211    end.
212
213no_gen_eval(Fun, Res) ->
214    case Fun() of
215	true -> [Res];
216	false -> []
217    end.
218
219no_gen_one_more(A, B) -> A + 1 =:= B.
220
221empty_generator(Config) when is_list(Config) ->
222    [] = [X || {X} <- [], (false or (X/0 > 3))],
223    ok.
224
225no_export(Config) when is_list(Config) ->
226    [] = [ _X = a || false ] ++ [ _X = a || false ],
227    ok.
228
229%% Test that variables in list comprehensions are
230%% correctly shadowed.
231
232shadow(Config) when is_list(Config) ->
233    Shadowed = nomatch,
234    _ = id(Shadowed),				%Eliminate warning.
235    L = [{Shadowed,Shadowed+1} || Shadowed <- lists:seq(7, 9)],
236    [{7,8},{8,9},{9,10}] = id(L),
237    [8,9] = id([Shadowed || {_,Shadowed} <- id(L),
238			    Shadowed < 10]),
239    ok.
240
241effect(Config) when is_list(Config) ->
242    ct:timetrap({minutes,10}),
243    [{42,{a,b,c}}] =
244	do_effect(fun(F, L) ->
245			  [F({V1,V2}) ||
246			      #{<<1:500>>:=V1,<<2:301>>:=V2} <- L],
247			  ok
248		  end, id([#{},x,#{<<1:500>>=>42,<<2:301>>=>{a,b,c}}])),
249
250    %% Will trigger the time-trap timeout if not tail-recursive.
251    case ?MODULE of
252	lc_SUITE ->
253	    _ = [{'EXIT',{badarg,_}} =
254		     (catch binary_to_atom(<<C/utf8>>, utf8)) ||
255		    C <- lists:seq(16#FF10000, 16#FFFFFFF)];
256	_ ->
257	    ok
258    end,
259
260    ok.
261
262do_effect(Lc, L) ->
263    put(?MODULE, []),
264    F = fun(V) -> put(?MODULE, [V|get(?MODULE)]) end,
265    ok = Lc(F, L),
266    lists:reverse(erase(?MODULE)).
267
268id(I) -> I.
269
270fc(Args, {'EXIT',{function_clause,[{?MODULE,_,Args,_}|_]}}) -> ok;
271fc(Args, {'EXIT',{function_clause,[{?MODULE,_,Arity,_}|_]}})
272  when length(Args) =:= Arity ->
273    true = test_server:is_native(?MODULE);
274fc(Args, {'EXIT',{{case_clause,ActualArgs},_}})
275  when ?MODULE =:= lc_inline_SUITE ->
276    Args = tuple_to_list(ActualArgs).
277
278-file("bad_lc.erl", 1).
279bad_generator(List) ->                          %Line 2
280    [I ||                                       %Line 3
281        I <- List].                             %Line 4
282bad_generator_bc(List) ->                       %Line 5
283    << <<I:4>> ||                               %Line 6
284        I <- List>>.                            %Line 7
285