%%% -*- erlang-indent-level: 2 -*-
%%%-------------------------------------------------------------------
-module(bs_potpurri).
-export([test/0]).
test() ->
ok = integer(),
ok = signed_integer(),
ok = dynamic(),
ok = more_dynamic(),
ok = mml(),
ok.
%% compile(Opts0) ->
%% case proplists:get_bool(core, Opts0) of
%% true ->
%% test:note(?MODULE, "disabling compilation from core - BUG"),
%% Opts = [{core,false}|Opts0];
%% false ->
%% Opts = Opts0
%% end,
%% hipe:c(?MODULE, Opts).
integer() ->
0 = get_int(mkbin([])),
0 = get_int(mkbin([0])),
42 = get_int(mkbin([42])),
255 = get_int(mkbin([255])),
256 = get_int(mkbin([1,0])),
257 = get_int(mkbin([1,1])),
258 = get_int(mkbin([1,2])),
258 = get_int(mkbin([1,2])),
65534 = get_int(mkbin([255,254])),
16776455 = get_int(mkbin([255,253,7])),
4245492555 = get_int(mkbin([253,13,19,75])),
L = [200,1,19,128,222,42,97,111,200,1,19,128,222,42,97,111],
ok = cmp128(mkbin(L), uint(L)),
ok = fun_clause(catch get_int(mkbin(lists:seq(1,5)))),
ok.
get_int(<<I:0>>) -> I;
get_int(<<I:8>>) -> I;
get_int(<<I:16>>) -> I;
get_int(<<I:24>>) -> I;
get_int(<<I:32>>) -> I.
cmp128(<<I:128>>, I) -> ok;
cmp128(_Bin, _I) -> not_ok.
signed_integer() ->
{no_match,_} = sint(mkbin([])),
{no_match,_} = sint(mkbin([1,2,3])),
127 = sint(mkbin([127])),
-1 = sint(mkbin([255])),
-128 = sint(mkbin([128])),
42 = sint(mkbin([42,255])),
127 = sint(mkbin([127,255])),
ok.
sint(Bin) ->
case Bin of
<<I:8/signed>> -> I;
<<I:8/signed,_:3,_:5>> -> I;
Other -> {no_match,Other}
end.
uint(L) -> uint(L, 0).
uint([H|T], Acc) -> uint(T, Acc bsl 8 bor H);
uint([], Acc) -> Acc.
dynamic() ->
ok = dynamic(mkbin([255]), 8),
ok = dynamic(mkbin([255,255]), 16),
ok = dynamic(mkbin([255,255,255]), 24),
ok = dynamic(mkbin([255,255,255,255]), 32),
ok.
dynamic(Bin, S1) when S1 >= 0 ->
S2 = bit_size(Bin) - S1,
dynamic(Bin, S1, S2, (1 bsl S1) - 1, (1 bsl S2) - 1),
dynamic(Bin, S1-1);
dynamic(_Bin, _) -> ok.
dynamic(Bin, S1, S2, A, B) ->
%% io:format("~p ~p ~p ~p\n", [S1,S2,A,B]),
case Bin of
<<A:S1,B:S2>> ->
%% io:format("~p ~p ~p ~p\n", [S1,S2,A,B]),
ok;
<<A1:S1,B2:S2>> -> erlang:error(badmatch, [Bin,S1,S2,A,B,A1,B2])
end.
more_dynamic() ->
%% Unsigned big-endian numbers.
Unsigned = fun(Bin, List, SkipBef, N) ->
SkipAft = bit_size(Bin) - N - SkipBef,
<<_I1:SkipBef,Int:N,_I2:SkipAft>> = Bin,
Int = make_int(List, N, 0)
end,
ok = more_dynamic1(Unsigned, funny_binary(42)),
%% Signed big-endian numbers.
Signed = fun(Bin, List, SkipBef, N) ->
SkipAft = bit_size(Bin) - N - SkipBef,
<<_I1:SkipBef,Int:N/signed,_I2:SkipAft>> = Bin,
case make_signed_int(List, N) of
Int -> ok;
Other ->
io:format("Bin = ~p,", [Bin]),
io:format("SkipBef = ~p, N = ~p", [SkipBef,N]),
io:format("Expected ~p, got ~p", [Int,Other]),
exit(Other)
end
end,
ok = more_dynamic1(Signed, funny_binary(43)),
%% Unsigned little-endian numbers.
UnsLittle = fun(Bin, List, SkipBef, N) ->
SkipAft = bit_size(Bin) - N - SkipBef,
<<_I1:SkipBef,Int:N/little,_I2:SkipAft>> = Bin,
Int = make_int(big_to_little(List, N), N, 0)
end,
more_dynamic1(UnsLittle, funny_binary(44)),
%% Signed little-endian numbers.
SignLittle = fun(Bin, List, SkipBef, N) ->
SkipAft = bit_size(Bin) - N - SkipBef,
<<_I1:SkipBef,Int:N/signed-little,_I2:SkipAft>> = Bin,
Little = big_to_little(List, N),
Int = make_signed_int(Little, N)
end,
ok = more_dynamic1(SignLittle, funny_binary(45)),
ok.
funny_binary(N) ->
B0 = erlang:md5([N]),
{B1,_B2} = split_binary(B0, byte_size(B0) div 2),
B1.
more_dynamic1(Action, Bin) ->
BitList = bits_to_list(binary_to_list(Bin), 16#80),
more_dynamic2(Action, Bin, BitList, 0).
more_dynamic2(Action, Bin, [_|T]=List, Bef) ->
more_dynamic3(Action, Bin, List, Bef, bit_size(Bin)),
more_dynamic2(Action, Bin, T, Bef+1);
more_dynamic2(_Action, _Bin, [], _Bef) -> ok.
more_dynamic3(Action, Bin, List, Bef, Aft) when Bef =< Aft ->
%% io:format("~p, ~p", [Bef,Aft-Bef]),
Action(Bin, List, Bef, Aft-Bef),
more_dynamic3(Action, Bin, List, Bef, Aft-1);
more_dynamic3(_, _, _, _, _) -> ok.
big_to_little(List, N) -> big_to_little(List, N, []).
big_to_little([B0,B1,B2,B3,B4,B5,B6,B7|T], N, Acc) when N >= 8 ->
big_to_little(T, N-8, [B0,B1,B2,B3,B4,B5,B6,B7|Acc]);
big_to_little(List, N, Acc) -> lists:sublist(List, 1, N) ++ Acc.
make_signed_int(_List, 0) -> 0;
make_signed_int([0|_]=List, N) -> make_int(List, N, 0);
make_signed_int([1|_]=List0, N) ->
List1 = reversed_sublist(List0, N, []),
List2 = two_complement_and_reverse(List1, 1, []),
-make_int(List2, length(List2), 0).
reversed_sublist(_List, 0, Acc) -> Acc;
reversed_sublist([H|T], N, Acc) -> reversed_sublist(T, N-1, [H|Acc]).
two_complement_and_reverse([H|T], Carry, Acc) ->
Sum = 1 - H + Carry,
two_complement_and_reverse(T, Sum div 2, [Sum rem 2|Acc]);
two_complement_and_reverse([], Carry, Acc) -> [Carry|Acc].
make_int(_List, 0, Acc) -> Acc;
make_int([H|T], N, Acc) -> make_int(T, N-1, Acc bsl 1 bor H).
bits_to_list([_|T], 0) -> bits_to_list(T, 16#80);
bits_to_list([H|_]=List, Mask) ->
[case H band Mask of
0 -> 0;
_ -> 1
end|bits_to_list(List, Mask bsr 1)];
bits_to_list([], _) -> [].
fun_clause({'EXIT',{function_clause,_}}) -> ok.
mkbin(L) when is_list(L) -> list_to_binary(L).
mml() ->
single_byte_binary = mml_choose(<<42>>),
multi_byte_binary = mml_choose(<<42,43>>),
ok.
mml_choose(<<_:8>>) -> single_byte_binary;
mml_choose(<<_:8, _T/binary>>) -> multi_byte_binary.
