%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 1997-2018. 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(num_bif_SUITE).
-include_lib("common_test/include/ct.hrl").
%% Tests the BIFs:
%% abs/1
%% float/1
%% float_to_list/1
%% float_to_list/2
%% integer_to_list/1
%% list_to_float/1
%% list_to_integer/1
%% round/1
%% trunc/1
%% floor/1
%% ceil/1
%% integer_to_binary/1
%% integer_to_binary/2
%% binary_to_integer/1
-export([all/0, suite/0, groups/0, init_per_suite/1, end_per_suite/1,
init_per_group/2, end_per_group/2, t_abs/1, t_float/1,
t_float_to_string/1, t_integer_to_string/1,
t_string_to_integer/1, t_list_to_integer_edge_cases/1,
t_string_to_float_safe/1, t_string_to_float_risky/1,
t_round/1, t_trunc_and_friends/1
]).
suite() -> [{ct_hooks,[ts_install_cth]}].
all() ->
[t_abs, t_float, t_float_to_string, t_integer_to_string,
{group, t_string_to_float}, t_string_to_integer, t_round,
t_trunc_and_friends, t_list_to_integer_edge_cases].
groups() ->
[{t_string_to_float, [],
[t_string_to_float_safe, t_string_to_float_risky]}].
init_per_suite(Config) ->
Config.
end_per_suite(_Config) ->
ok.
init_per_group(_GroupName, Config) ->
Config.
end_per_group(_GroupName, Config) ->
Config.
t_abs(Config) when is_list(Config) ->
%% Floats.
5.5 = abs(id(5.5)),
0.0 = abs(id(0.0)),
100.0 = abs(id(-100.0)),
%% Integers.
5 = abs(id(5)),
0 = abs(id(0)),
100 = abs(id(-100)),
%% The largest smallnum. OTP-3190.
X = id((1 bsl 27) - 1),
X = abs(X),
X = abs(X-1)+1,
X = abs(X+1)-1,
X = abs(-X),
X = abs(-X-1)-1,
X = abs(-X+1)+1,
%% Bignums.
BigNum = id(13984792374983749),
BigNum = abs(BigNum),
BigNum = abs(-BigNum),
ok.
t_float(Config) when is_list(Config) ->
0.0 = float(id(0)),
2.5 = float(id(2.5)),
0.0 = float(id(0.0)),
-100.55 = float(id(-100.55)),
42.0 = float(id(42)),
-100.0 = float(id(-100)),
%% Bignums.
4294967305.0 = float(id(4294967305)),
-4294967305.0 = float(id(-4294967305)),
%% Extremely big bignums.
Big = id(list_to_integer(id(lists:duplicate(2000, $1)))),
{'EXIT', {badarg, _}} = (catch float(Big)),
ok.
%% Tests float_to_list/1, float_to_list/2, float_to_binary/1, float_to_binary/2
t_float_to_string(Config) when is_list(Config) ->
rand_seed(),
test_fts("0.00000000000000000000e+00", 0.0),
test_fts("2.50000000000000000000e+01", 25.0),
test_fts("2.50000000000000000000e+00", 2.5),
test_fts("2.50000000000000000000e-01", 0.25),
test_fts("-3.50000000000000000000e+17", -350.0e15),
test_fts("1.00000000000000000000e+00",1.0),
test_fts("1.00000000000000000000e+00",1.0, []),
test_fts("-1.00000000000000000000e+00",-1.0, []),
test_fts("-1.00000000000000000000",-1.0, [{decimals, 20}]),
{'EXIT', {badarg, _}} = (catch float_to_list(1.0, [{decimals, -1}])),
{'EXIT', {badarg, _}} = (catch float_to_list(1.0, [{decimals, 254}])),
{'EXIT', {badarg, _}} = (catch float_to_list(1.0, [{scientific, 250}])),
{'EXIT', {badarg, _}} = (catch float_to_list(1.0e+300, [{decimals, 1}])),
{'EXIT', {badarg, _}} = (catch float_to_binary(1.0, [{decimals, -1}])),
{'EXIT', {badarg, _}} = (catch float_to_binary(1.0, [{decimals, 254}])),
{'EXIT', {badarg, _}} = (catch float_to_binary(1.0, [{scientific, 250}])),
{'EXIT', {badarg, _}} = (catch float_to_binary(1.0e+300, [{decimals, 1}])),
test_fts("1.0e+300",1.0e+300, [{scientific, 1}]),
test_fts("1.0",1.0, [{decimals, 249}, compact]),
test_fts("1",1.0,[{decimals,0}]),
test_fts("2",1.9,[{decimals,0}]),
test_fts("123456789012345680.0",123456789012345678.0,
[{decimals, 236}, compact]),
{'EXIT', {badarg, _}} = (catch float_to_list(
123456789012345678.0, [{decimals, 237}])),
{'EXIT', {badarg, _}} = (catch float_to_binary(
123456789012345678.0, [{decimals, 237}])),
test_fts("1." ++ lists:duplicate(249, $0) ++ "e+00",
1.0, [{scientific, 249}, compact]),
X1 = float_to_list(1.0),
X2 = float_to_list(1.0, [{scientific, 20}]),
X1 = X2,
Y1 = float_to_binary(1.0),
Y2 = float_to_binary(1.0, [{scientific, 20}]),
Y1 = Y2,
test_fts("1.000e+00",1.0, [{scientific, 3}]),
test_fts("1.000",1.0, [{decimals, 3}]),
test_fts("1.0",1.0, [{decimals, 1}]),
test_fts("1.0",1.0, [{decimals, 3}, compact]),
test_fts("1.12",1.123, [{decimals, 2}]),
test_fts("1.123",1.123, [{decimals, 3}]),
test_fts("1.123",1.123, [{decimals, 3}, compact]),
test_fts("1.1230",1.123, [{decimals, 4}]),
test_fts("1.12300",1.123, [{decimals, 5}]),
test_fts("1.123",1.123, [{decimals, 5}, compact]),
test_fts("1.1234",1.1234,[{decimals, 6}, compact]),
test_fts("1.00",1.005, [{decimals, 2}]), %% 1.005 is really 1.0049999999...
test_fts("-1.00",-1.005,[{decimals, 2}]),
test_fts("0.999",0.999, [{decimals, 3}]),
test_fts("-0.999",-0.999,[{decimals, 3}]),
test_fts("1.0",0.999, [{decimals, 2}, compact]),
test_fts("-1.0",-0.999,[{decimals, 2}, compact]),
test_fts("0.5",0.5, [{decimals, 1}]),
test_fts("-0.5",-0.5, [{decimals, 1}]),
"2.333333" = erlang:float_to_list(7/3, [{decimals, 6}, compact]),
"2.333333" = erlang:float_to_list(7/3, [{decimals, 6}]),
<<"2.333333">> = erlang:float_to_binary(7/3, [{decimals, 6}, compact]),
<<"2.333333">> = erlang:float_to_binary(7/3, [{decimals, 6}]),
test_fts("0.00000000000000000000e+00",0.0, [compact]),
test_fts("0.0",0.0, [{decimals, 10}, compact]),
test_fts("123000000000000000000.0",1.23e20, [{decimals, 10}, compact]),
test_fts("1.2300000000e+20",1.23e20, [{scientific, 10}, compact]),
test_fts("1.23000000000000000000e+20",1.23e20, []),
fts_rand_float_decimals(1000),
ok.
test_fts(Expect, Float) ->
Expect = float_to_list(Float),
BinExpect = list_to_binary(Expect),
BinExpect = float_to_binary(Float).
test_fts(Expect, Float, Args) ->
Expect = float_to_list(Float,Args),
BinExpect = list_to_binary(Expect),
BinExpect = float_to_binary(Float,Args).
rand_float_reasonable() ->
F = rand_float(),
case abs(F) > 1.0e238 of
true -> rand_float_reasonable();
false -> F
end.
fts_rand_float_decimals(0) -> ok;
fts_rand_float_decimals(N) ->
[begin
F0 = rand_float_reasonable(),
L0 = float_to_list(F0, [{decimals, D}]),
case conform_with_io_lib_format_os(F0,D) of
false -> ok;
true ->
IOL = lists:flatten(io_lib:format("~.*f", [D, F0])),
true = case L0 =:= IOL of
true -> true;
false ->
io:format("F0 = ~w ~w\n", [F0, <<F0/float>>]),
io:format("decimals = ~w\n", [D]),
io:format("float_to_list = ~s\n", [L0]),
io:format("io_lib:format = ~s\n", [IOL]),
false
end
end,
L1 = case D of
0 -> L0 ++ ".0";
_ -> L0
end,
F1 = list_to_float(L1),
Diff = abs(F0-F1),
MaxDiff = max_diff_decimals(F0, D),
ok = case Diff =< MaxDiff of
true -> ok;
false ->
io:format("F0 = ~w ~w\n", [F0, <<F0/float>>]),
io:format("L1 = ~s\n", [L1]),
io:format("F1 = ~w ~w\n", [F1, <<F1/float>>]),
io:format("Diff = ~w, MaxDiff = ~w\n", [Diff, MaxDiff]),
error
end
end
|| D <- lists:seq(0,15)],
fts_rand_float_decimals(N-1).
conform_with_io_lib_format_os(F, D) ->
case os:type() of
{win32,_} ->
%% io_lib:format("~.*f") buggy on windows? OTP-15010
false;
_ ->
conform_with_io_lib_format(F, D)
end.
conform_with_io_lib_format(_, 0) ->
%% io_lib:format("~.*f") does not support zero decimals
false;
conform_with_io_lib_format(_, D) when D > 10 ->
%% Seems float_to_list gets it slightly wrong sometimes for many decimals
false;
conform_with_io_lib_format(F, D) ->
%% io_lib:format prints '0' for input bits beyond mantissa precision
%% float_to_list treats those unknown input bits as if they were zeros.
math:log2(abs(F) * math:pow(10,D)) < 54.
max_diff_decimals(F, D) ->
IntBits = floor(math:log2(abs(F))) + 1,
FracBits = (52 - IntBits),
Log10_2 = 0.3010299956639812, % math:log10(2)
MaxDec = floor(FracBits * Log10_2),
Resolution = math:pow(2, IntBits - 53),
(math:pow(10, -min(D,MaxDec)) / 2) + Resolution.
%% Tests list_to_float/1.
t_string_to_float_safe(Config) when is_list(Config) ->
test_stf(0.0,"0.0"),
test_stf(0.0,"-0.0"),
test_stf(0.5,"0.5"),
test_stf(-0.5,"-0.5"),
test_stf(100.0,"1.0e2"),
test_stf(127.5,"127.5"),
test_stf(-199.5,"-199.5"),
{'EXIT',{badarg,_}} = (catch list_to_float(id("0"))),
{'EXIT',{badarg,_}} = (catch list_to_float(id("0..0"))),
{'EXIT',{badarg,_}} = (catch list_to_float(id("0e12"))),
{'EXIT',{badarg,_}} = (catch list_to_float(id("--0.0"))),
{'EXIT',{badarg,_}} = (catch binary_to_float(id(<<"0">>))),
{'EXIT',{badarg,_}} = (catch binary_to_float(id(<<"0..0">>))),
{'EXIT',{badarg,_}} = (catch binary_to_float(id(<<"0e12">>))),
{'EXIT',{badarg,_}} = (catch binary_to_float(id(<<"--0.0">>))),
UBin = <<0:3,(id(<<"0.0">>))/binary,0:5>>,
<<_:3,UnAlignedBin:3/binary,0:5>> = id(UBin),
0.0 = binary_to_float(UnAlignedBin),
ABin = <<0:8,(id(<<"1.0">>))/binary,0:8>>,
<<_:8,AlignedBin:3/binary,0:8>> = id(ABin),
1.0 = binary_to_float(AlignedBin),
ok.
%% This might crash the emulator...
%% (Known to crash the Unix version of Erlang 4.4.1)
t_string_to_float_risky(Config) when is_list(Config) ->
Many_Ones = lists:duplicate(25000, id($1)),
id(list_to_float("2."++Many_Ones)),
{'EXIT', {badarg, _}} = (catch list_to_float("2"++Many_Ones)),
id(binary_to_float(list_to_binary("2."++Many_Ones))),
{'EXIT', {badarg, _}} = (catch binary_to_float(
list_to_binary("2"++Many_Ones))),
ok.
test_stf(Expect,List) ->
Expect = list_to_float(List),
Bin = list_to_binary(List),
Expect = binary_to_float(Bin).
%% Tests round/1.
t_round(Config) when is_list(Config) ->
0 = round(id(0.0)),
0 = round(id(0.4)),
1 = round(id(0.5)),
0 = round(id(-0.4)),
-1 = round(id(-0.5)),
255 = round(id(255.3)),
256 = round(id(255.6)),
-1033 = round(id(-1033.3)),
-1034 = round(id(-1033.6)),
% OTP-3722:
X = id((1 bsl 27) - 1),
MX = -X,
MXm1 = -X-1,
MXp1 = -X+1,
F = id(X + 0.0),
X = round(F),
X = round(F+1)-1,
X = round(F-1)+1,
MX = round(-F),
MXm1 = round(-F-1),
MXp1 = round(-F+1),
X = round(F+0.1),
X = round(F+1+0.1)-1,
X = round(F-1+0.1)+1,
MX = round(-F+0.1),
MXm1 = round(-F-1+0.1),
MXp1 = round(-F+1+0.1),
X = round(F-0.1),
X = round(F+1-0.1)-1,
X = round(F-1-0.1)+1,
MX = round(-F-0.1),
MXm1 = round(-F-1-0.1),
MXp1 = round(-F+1-0.1),
0.5 = abs(round(F+0.5)-(F+0.5)),
0.5 = abs(round(F-0.5)-(F-0.5)),
0.5 = abs(round(-F-0.5)-(-F-0.5)),
0.5 = abs(round(-F+0.5)-(-F+0.5)),
%% Bignums.
4294967296 = round(id(4294967296.1)),
4294967297 = round(id(4294967296.9)),
-4294967296 = -round(id(4294967296.1)),
-4294967297 = -round(id(4294967296.9)),
6209607916799025 = round(id(6209607916799025.0)),
-6209607916799025 = round(id(-6209607916799025.0)),
ok.
%% Test trunc/1, floor/1, ceil/1, and round/1.
t_trunc_and_friends(_Config) ->
MinusZero = 0.0 / (-1.0),
0 = trunc_and_friends(MinusZero),
0 = trunc_and_friends(0.0),
5 = trunc_and_friends(5.3333),
-10 = trunc_and_friends(-10.978987),
%% The largest smallnum, converted to float (OTP-3722):
X = id((1 bsl 27) - 1),
F = X + 0.0,
io:format("X = ~p/~w/~w, F = ~p/~w/~w, trunc(F) = ~p/~w/~w~n",
[X, X, binary_to_list(term_to_binary(X)),
F, F, binary_to_list(term_to_binary(F)),
trunc_and_friends(F),
trunc_and_friends(F),
binary_to_list(term_to_binary(trunc_and_friends(F)))]),
X = trunc_and_friends(F),
X = trunc_and_friends(F+1)-1,
X = trunc_and_friends(F-1)+1,
X = -trunc_and_friends(-F),
X = -trunc_and_friends(-F-1)-1,
X = -trunc_and_friends(-F+1)+1,
%% Bignums.
4294967305 = trunc_and_friends(4294967305.7),
-4294967305 = trunc_and_friends(-4294967305.7),
18446744073709551616 = trunc_and_friends(float(1 bsl 64)),
-18446744073709551616 = trunc_and_friends(-float(1 bsl 64)),
%% Random.
rand_seed(),
t_trunc_and_friends_rand(100),
ok.
rand_seed() ->
rand:seed(exrop),
io:format("\n*** rand:export_seed() = ~w\n\n", [rand:export_seed()]),
ok.
rand_float() ->
F0 = rand:uniform() * math:pow(10, 50*rand:normal()),
case rand:uniform() of
U when U < 0.5 -> -F0;
_ -> F0
end.
t_trunc_and_friends_rand(0) ->
ok;
t_trunc_and_friends_rand(N) ->
_ = trunc_and_friends(rand_float()),
t_trunc_and_friends_rand(N-1).
trunc_and_friends(F) ->
Trunc = trunc(F),
Floor = floor(F),
Ceil = ceil(F),
Round = round(F),
Trunc = trunc(Trunc),
Floor = floor(Floor),
Ceil = ceil(Ceil),
Round = round(Round),
Trunc = trunc(float(Trunc)),
Floor = floor(float(Floor)),
Ceil = ceil(float(Ceil)),
Round = round(float(Round)),
true = Floor =< Trunc andalso Trunc =< Ceil,
true = Ceil - Floor =< 1,
true = Round =:= Floor orelse Round =:= Ceil,
if
F < 0 ->
Trunc = Ceil;
true ->
Trunc = Floor
end,
Trunc.
%% Tests integer_to_binary/1.
t_integer_to_string(Config) when is_list(Config) ->
test_its("0",0),
test_its("42",42),
test_its("-42",-42),
test_its("32768",32768),
test_its("268435455",268435455),
test_its("-268435455",-268435455),
test_its("123456932798748738738",123456932798748738738),
%% 1 bsl 33, just beyond 32 bit
test_its("8589934592",8589934592),
test_its("-8589934592",-8589934592),
%% 1 bsl 65, just beyond 64 bit
test_its("36893488147419103232",36893488147419103232),
test_its("-36893488147419103232",-36893488147419103232),
%% Bignums.
BigBin = id(list_to_binary(lists:duplicate(2000, id($1)))),
Big = erlang:binary_to_integer(BigBin),
BigBin = erlang:integer_to_binary(Big),
%% Invalid types
lists:foreach(fun(Value) ->
{'EXIT', {badarg, _}} =
(catch erlang:integer_to_binary(Value)),
{'EXIT', {badarg, _}} =
(catch erlang:integer_to_list(Value))
end,[atom,1.2,0.0,[$1,[$2]]]),
%% Base-2 integers
test_its("0", 0, 2),
test_its("1", 1, 2),
test_its("110110", 54, 2),
test_its("-1000000", -64, 2),
%% Base-16 integers
test_its("0", 0, 16),
test_its("A", 10, 16),
test_its("D4BE", 54462, 16),
test_its("-D4BE", -54462, 16),
lists:foreach(fun(Value) ->
{'EXIT', {badarg, _}} =
(catch erlang:integer_to_binary(Value, 8)),
{'EXIT', {badarg, _}} =
(catch erlang:integer_to_list(Value, 8))
end,[atom,1.2,0.0,[$1,[$2]]]),
ok.
test_its(List,Int) ->
Int = list_to_integer(List),
Int = binary_to_integer(list_to_binary(List)).
test_its(List,Int,Base) ->
Int = list_to_integer(List, Base),
Int = binary_to_integer(list_to_binary(List), Base).
%% Tests binary_to_integer/1.
t_string_to_integer(Config) when is_list(Config) ->
0 = erlang:binary_to_integer(id(<<"00">>)),
0 = erlang:binary_to_integer(id(<<"-0">>)),
0 = erlang:binary_to_integer(id(<<"+0">>)),
test_sti(0),
test_sti(1),
test_sti(-1),
test_sti(42),
test_sti(-12),
test_sti(32768),
test_sti(268435455),
test_sti(-268435455),
% Interesting values around 2-pows, such as MIN_SMALL and MAX_SMALL.
lists:foreach(fun(Bits) ->
N = 1 bsl Bits,
test_sti(N - 1),
test_sti(N),
test_sti(N + 1)
end,
lists:seq(16, 130)),
%% Bignums.
test_sti(123456932798748738738,16),
test_sti(list_to_integer(lists:duplicate(2000, $1))),
%% unalign string
Str = <<"10">>,
UnalignStr = <<0:3, (id(Str))/binary, 0:5>>,
<<_:3, SomeStr:2/binary, _:5>> = id(UnalignStr),
10 = erlang:binary_to_integer(SomeStr),
%% Invalid types
lists:foreach(fun(Value) ->
{'EXIT', {badarg, _}} =
(catch binary_to_integer(Value)),
{'EXIT', {badarg, _}} =
(catch erlang:list_to_integer(Value))
end,[atom,1.2,0.0,[$1,[$2]]]),
% Default base error cases
lists:foreach(fun(Value) ->
{'EXIT', {badarg, _}} =
(catch erlang:binary_to_integer(
list_to_binary(Value))),
{'EXIT', {badarg, _}} =
(catch erlang:list_to_integer(Value))
end,["1.0"," 1"," -1","","+"]),
% Custom base error cases
lists:foreach(fun({Value,Base}) ->
{'EXIT', {badarg, _}} =
(catch binary_to_integer(
list_to_binary(Value),Base)),
{'EXIT', {badarg, _}} =
(catch erlang:list_to_integer(Value,Base))
end,[{" 1",1},{" 1",37},{"2",2},{"B",11},{"b",11},{":", 16},
{"1111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111z",16},
{"1z111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111111",16},
{"111z11111111",16}]),
%% log2 calculation overflow bug in do_integer_to_list (OTP-12624)
%% Would crash with segv
0 = list_to_integer(lists:duplicate(10000000,$0)),
ok.
%% Tests edge cases for list_to_integer; compares with known good values
t_list_to_integer_edge_cases(Config) when is_list(Config) ->
%% Take integer literals and compare to their representation in ExtTerm
T = [
{16, "0", <<131,97,0>>},
{16, "-0", <<131,97,0>>},
{16, "f", <<131,97,15>>},
{16, "-f", <<131,98,255,255,255,241>>},
{16, "0000000000000000000000000000000000000000000000000f",
<<131,97,15>>},
{16, "-0000000000000000000000000000000000000000000000000f",
<<131,98,255,255,255,241>>},
{16, "ffffffff", <<131,110,4,0,255,255,255,255>>},
{16, "-ffffffff", <<131,110,4,1,255,255,255,255>>},
{16, "7fffffff", <<131,110,4,0,255,255,255,127>>},
{16, "-7fffffff", <<131,98,128,0,0,1>>},
{16, "ffffffffffffffff",
<<131,110,8,0,255,255,255,255,255,255,255,255>>},
{16, "-ffffffffffffffff",
<<131,110,8,1,255,255,255,255,255,255,255,255>>},
{16, "7fffffffffffffff",
<<131,110,8,0,255,255,255,255,255,255,255,127>>},
{16, "-7fffffffffffffff",
<<131,110,8,1,255,255,255,255,255,255,255,127>>},
%% Alleged 32-bit corner case (should not happen on 64-bit). At 32-4
%% bits we may corrupt sign bit and fall out of SMALL_INT range.
{2, "1000000000000000000000000000", <<131,98,8,0,0,0>>},
{2, "-1000000000000000000000000000", <<131,98,248,0,0,0>>},
%% 64-bit corner case (should not happen on 32-bit) at 64-4 bits we
%% corrupt sign bit and fall out of SMALL_INT range (bam! all dead)
{2, "100000000000000000000000000000000000000000000000000000000000",
<<131,110,8,0,0,0,0,0,0,0,0,8>>},
{2, "-100000000000000000000000000000000000000000000000000000000000",
<<131,110,8,1,0,0,0,0,0,0,0,8>>}
],
[begin
io:format("~s base ~p vs ~p~n", [Str, Base, Bin]),
FromStr = list_to_integer(Str, Base),
FromStr = binary_to_term(Bin)
end || {Base, Str, Bin} <- T],
ok.
test_sti(Num) ->
[begin
io:format("Testing ~p:~p",[Num,Base]),
test_sti(Num,Base)
end|| Base <- lists:seq(2,36)].
test_sti(Num,Base) ->
Neg = -Num,
Num = list_to_integer(int2list(Num,Base),Base),
Neg = list_to_integer(int2list(Num*-1,Base),Base),
Num = binary_to_integer(int2bin(Num,Base),Base),
Neg = binary_to_integer(int2bin(Num*-1,Base),Base).
% Calling this function (which is not supposed to be inlined) prevents
% the compiler from calculating the answer, so we don't test the compiler
% instead of the newest runtime system.
id(X) -> X.
%% Uses the printing library to to integer_to_binary conversions.
int2bin(Int,Base) when Base < 37 ->
iolist_to_binary(int2list(Int,Base)).
int2list(Int,Base) when Base < 37 ->
lists:flatten(io_lib:format("~."++integer_to_list(Base)++"B",[Int])).
