%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 2006-2009. All Rights Reserved.
%%
%% The contents of this file are subject to the Erlang Public License,
%% Version 1.1, (the "License"); you may not use this file except in
%% compliance with the License. You should have received a copy of the
%% Erlang Public License along with this software. If not, it can be
%% retrieved online at http://www.erlang.org/.
%%
%% Software distributed under the License is distributed on an "AS IS"
%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
%% the License for the specific language governing rights and limitations
%% under the License.
%%
%% %CopyrightEnd%
%%
-module(record_access_in_guards).
-export([t/0]).
-record(r, {a = 4,b}).
-record(r1, {a,b}).
-record(r2, {a = #r1{},b,c=length([1,2,3])}).
-record(r3, {a = fun(_) -> #r1{} end(1), b}).
t() ->
foo = fun(A) when A#r1.a > A#r1.b -> foo end(#r1{b = 2}),
0 = fun(A) when A#r2.a -> 0 end(#r2{a = true}),
1 = fun(A) when (#r1{a = A})#r1.a > 2 -> 1 end(3),
2 = fun(N) when ((#r2{a = #r{a = 4}, b = length([a,b,c])})#r2.a)#r.a > N ->
2 end(2),
3 = fun(A) when (A#r2.a)#r1.a =:= 3 -> 3 end(#r2{a = #r1{a = 3}}),
ok = fun() ->
F = fun(A) when record(A#r.a, r1) -> 4;
(A) when record(A#r1.a, r1) -> 5
end,
5 = F(#r1{a = #r1{}}),
4 = F(#r{a = #r1{}}),
ok
end(),
3 = fun(A) when record(A#r1.a, r),
(A#r1.a)#r.a > 3 -> 3
end(#r1{a = #r{a = 4}}),
7 = fun(A) when record(A#r3.a, r1) -> 7 end(#r3{}),
[#r1{a = 2,b = 1}] =
fun() ->
[A || A <- [#r1{a = 1, b = 3},
#r2{a = 2,b = 1},
#r1{a = 2, b = 1}],
A#r1.a >
A#r1.b]
end(),
{[_],b} =
fun(L) ->
%% A is checked only once:
R1 = [{A,B} || A <- L, A#r1.a, B <- L, A#r1.b],
A = #r2{a = true},
%% A is checked again:
B = if A#r1.a -> a; true -> b end,
{R1,B}
end([#r1{a = true, b = true}]),
p = fun(A) when (A#r1.a =:= 2) or (A#r2.a =:= 1) -> o;
(_) -> p
end(#r1{a = 2}),
o = fun(A) when (A#r1.a =:= 2) orelse (A#r2.a =:= 1) -> o;
(_) -> p
end(#r1{a = 2}),
3 = fun(A) when A#r1.a > 3,
record(A, r1) -> 3
end(#r1{a = 5}),
ok = fun() ->
F = fun(A) when (A#r2.a =:= 1) orelse (A#r2.a) -> 2;
(A) when (A#r1.a =:= 1) orelse (A#r1.a) -> 1;
(A) when (A#r2.a =:= 2) andalso (A#r2.b) -> 3
end,
1 = F(#r1{a = 1}),
2 = F(#r2{a = true}),
3 = F(#r2{a = 2, b = true}),
ok
end(),
b = fun(A) when false or not (A#r.a =:= 1) -> a;
(_) -> b
end(#r1{a = 1}),
b = fun(A) when not (A#r.a =:= 1) or false -> a;
(_) -> b
end(#r1{a = 1}),
ok = fun() ->
F = fun(A) when not (A#r.a =:= 1) -> yes;
(_) -> no
end,
no = F(#r1{a = 2}),
yes = F(#r{a = 2}),
no = F(#r{a = 1}),
ok
end(),
a = fun(A) when record(A, r),
A#r.a =:= 1,
A#r.b =:= 2 ->a
end(#r{a = 1, b = 2}),
a = fun(A) when erlang:is_record(A, r),
A#r.a =:= 1,
A#r.b =:= 2 -> a
end(#r{a = 1, b = 2}),
a = fun(A) when is_record(A, r),
A#r.a =:= 1,
A#r.b =:= 2 -> a
end(#r{a = 1, b = 2}),
nop = fun(A) when (is_record(A, r1) and (A#r1.a > 3)) or (A#r2.a < 1) ->
japp;
(_) ->
nop
end(#r2{a = 0}),
nop = fun(A) when (A#r1.a > 3) or (A#r2.a < 1) -> japp;
(_) ->
nop
end(#r2{a = 0}),
ok = fun() ->
F = fun(A) when (A#r1.a =:= 2) or (A#r2.a =:= 1) -> o;
(_) -> p
end,
p = F(#r2{a = 1}),
p = F(#r1{a = 2}),
ok
end(),
ok = fun() ->
F = fun(A) when fail, A#r1.a; A#r1.a -> ab;
(_) -> bu
end,
ab = F(#r1{a = true}),
bu = F(#r2{a = true}),
ok
end(),
both = fun(A) when A#r.a, A#r.b -> both
end(#r{a = true, b = true}),
ok = fun() ->
F = fun(A, B) when ((A#r1.a) orelse (B#r2.a))
or (B#r2.b) or (A#r1.b) -> true;
(_, _) -> false
end,
true = F(#r1{a = false, b = false}, #r2{a = false, b = true}),
false = F(#r1{a = true, b = true}, #r1{a = false, b = true}),
ok
end(),
ok = fun(R) ->
F = fun(Head, Version, Tab) ->
VersionOK = (Head#r.a =:= Version),
if
Tab =:= Head#r.b, VersionOK ->
ok;
true ->
error
end
end,
ok = F(R, 42, tab),
error = F(R, 42, a),
error = F(R, 0, tab),
{'EXIT',{{badrecord,r},_}} = (catch F({x,y,z}, 4, 5)),
ok
end(#r{a=42,b=tab}),
ok.
