%%% -*- erlang-indent-level: 2 -*-
%%%-------------------------------------------------------------------
%%% File : bs_match.erl
%%% Author : Per Gustafsson <[email protected]>
%%% Purpose : Performs simple matching and construction of binaries
%%% TODO : Add binary and float tests
%%% Created : 20 Feb 2004
%%%-------------------------------------------------------------------
-module(bs_match).
-export([test/0]).
test() ->
Funs = [fun test_aligned/0, fun test_unaligned/0,
fun test_zero_tail/0, fun test_integer_matching/0,
fun test_writable_bin/0],
lists:foreach(fun (F) -> ok = F() end, Funs).
%%-------------------------------------------------------------------
%% Test aligned accesses
test_aligned() ->
10 = aligned_skip_bits_all(1, <<10,11,12>>),
ok = aligned().
aligned_skip_bits_all(N, Bin) ->
<<X:N/integer-unit:8, _/binary>> = Bin,
X.
aligned() ->
Tail1 = mkbin([]),
{258, Tail1} = al_get_tail_used(mkbin([1,2])),
Tail2 = mkbin(lists:seq(1, 127)),
{35091, Tail2} = al_get_tail_used(mkbin([137,19|Tail2])),
64896 = al_get_tail_unused(mkbin([253,128])),
64895 = al_get_tail_unused(mkbin([253,127|lists:seq(42, 255)])),
Tail3 = mkbin(lists:seq(0, 19)),
{0, Tail1} = get_dyn_tail_used(Tail1, 0),
{0, Tail3} = get_dyn_tail_used(mkbin([Tail3]), 0),
{73, Tail3} = get_dyn_tail_used(mkbin([73|Tail3]), 8),
0 = get_dyn_tail_unused(mkbin([]), 0),
233 = get_dyn_tail_unused(mkbin([233]), 8),
23 = get_dyn_tail_unused(mkbin([23,22,2]), 8),
ok.
mkbin(L) when is_list(L) -> list_to_binary(L).
al_get_tail_used(<<A:16,T/binary>>) -> {A, T}.
al_get_tail_unused(<<A:16,_/binary>>) -> A.
%%-------------------------------------------------------------------
%% Test unaligned accesses
test_unaligned() ->
10 = unaligned_skip_bits_all(8, <<10,11,12>>),
ok = unaligned().
unaligned_skip_bits_all(N, Bin) ->
<<X:N, _/binary>> = Bin,
X.
unaligned() ->
{'EXIT', {function_clause,_}} = (catch get_tail_used(mkbin([42]))),
{'EXIT', {{badmatch,_},_}} = (catch get_dyn_tail_used(mkbin([137]), 3)),
{'EXIT', {function_clause,_}} = (catch get_tail_unused(mkbin([42,33]))),
{'EXIT', {{badmatch,_},_}} = (catch get_dyn_tail_unused(mkbin([44]), 7)),
ok.
get_tail_used(<<A:1, T/binary>>) -> {A, T}.
get_tail_unused(<<A:15, _/binary>>) -> A.
get_dyn_tail_used(Bin, Sz) ->
<<A:Sz, T/binary>> = Bin,
{A,T}.
get_dyn_tail_unused(Bin, Sz) ->
<<A:Sz, _T/binary>> = Bin,
A.
%%-------------------------------------------------------------------
%% Test zero tail
test_zero_tail() ->
42 = zt8(mkbin([42])),
{'EXIT', {function_clause, _}} = (catch zt8(mkbin([1,2]))),
{'EXIT', {function_clause, _}} = (catch zt44(mkbin([1,2]))),
ok.
zt8(<<A:8>>) -> A.
zt44(<<_:4,_:4>>) -> ok.
%%-------------------------------------------------------------------
%% Test integer matching
test_integer_matching() ->
ok = test_static_integer_matching_1(),
ok = test_static_integer_matching_2(),
ok = test_static_integer_matching_3(),
ok = test_static_integer_matching_4(),
DynFun = fun (N) -> ok = test_dynamic_integer_matching(N) end,
lists:foreach(DynFun, [28, 27, 9, 17, 25, 8, 16, 24, 32]).
test_static_integer_matching_1() ->
<<0:6, -25:28/integer-signed, 0:6>> = s11(),
<<0:6, -25:28/integer-little-signed, 0:6>> = s12(),
<<0:6, 25:28/integer-little, 0:6>> = s13(),
<<0:6, 25:28, 0:6>> = s14(),
ok.
s11() ->
<<0:6, -25:28/integer-signed, 0:6>>.
s12() ->
<<0:6, -25:28/integer-little-signed, 0:6>>.
s13() ->
<<0:6, 25:28/integer-little, 0:6>>.
s14() ->
<<0:6, 25:28, 0:6>>.
test_static_integer_matching_2() ->
<<0:6, -25:20/integer-signed, 0:6>> = s21(),
<<0:6, -25:20/integer-little-signed, 0:6>> = s22(),
<<0:6, 25:20/integer-little, 0:6>> = s23(),
<<0:6, 25:20, 0:6>> = s24(),
ok.
s21() ->
<<0:6, -25:20/integer-signed, 0:6>>.
s22() ->
<<0:6, -25:20/integer-little-signed, 0:6>>.
s23() ->
<<0:6, 25:20/integer-little, 0:6>>.
s24() ->
<<0:6, 25:20, 0:6>>.
test_static_integer_matching_3() ->
<<0:6, -25:12/integer-signed, 0:6>> = s31(),
<<0:6, -25:12/integer-little-signed, 0:6>> = s32(),
<<0:6, 25:12/integer-little, 0:6>> = s33(),
<<0:6, 25:12, 0:6>> = s34(),
ok.
s31() ->
<<0:6, -25:12/integer-signed, 0:6>>.
s32() ->
<<0:6, -25:12/integer-little-signed, 0:6>>.
s33() ->
<<0:6, 25:12/integer-little, 0:6>>.
s34() ->
<<0:6, 25:12, 0:6>>.
test_static_integer_matching_4() ->
<<0:6, -3:4/integer-signed, 0:6>> = s41(),
<<0:6, -3:4/integer-little-signed, 0:6>> = s42(),
<<0:6, 7:4/integer-little, 0:6>> = s43(),
<<0:6, 7:4, 0:6>> = s44(),
ok.
s41() ->
<<0:6, -3:4/integer-signed, 0:6>>.
s42() ->
<<0:6, -3:4/integer-little-signed, 0:6>>.
s43() ->
<<0:6, 7:4/integer-little, 0:6>>.
s44() ->
<<0:6, 7:4, 0:6>>.
test_dynamic_integer_matching(N) ->
S = 32 - N,
<<-12:N/integer-signed, 0:S>> = <<-12:N/integer-signed, 0:S>>,
<<-12:N/integer-little-signed, 0:S>> = <<-12:N/integer-little-signed, 0:S>>,
<<12:N/integer, 0:S>> = <<12:N/integer, 0:S>>,
<<12:N/integer-little, 0:S>> = <<12:N/integer-little, 0:S>>,
ok.
test_writable_bin() ->
test_writable_bin(<<>>, 0),
ok.
test_writable_bin(Bin, 128) ->
Bin;
test_writable_bin(Bin0, N) when N < 128 ->
Bin1 = <<Bin0/binary, N>>,
<<_/utf8, _/binary>> = Bin1,
test_writable_bin(Bin1, N+1).
