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%% -*- erlang-indent-level: 2 -*-
%%--------------------------------------------------------------------
%% Tests that basic cases of binary construction work
%%--------------------------------------------------------------------
-module(bs_construct).
-export([test/0]).
test() ->
<<42>> = sz(8),
<<42:8/little>> = sz_little(8),
<<55>> = take_five(1, 3, 1, 7, 4),
ok = bs5(),
16#10000008 = bit_size(large_bin(1, 2, 3, 4)),
ok = bad_ones(),
ok.
%%--------------------------------------------------------------------
%% Taken from a bug report submitted by Dan Wallin (24 Oct 2003), the
%% following cases test construction of binaries whose segments have
%% sizes that are statically unknown.
sz(S) ->
<<42:S>>.
sz_little(S) ->
<<42:S/little>>.
take_five(A, Head, FB, C, Tail) ->
<<A:Head, FB:1, C:Tail>>.
%%--------------------------------------------------------------------
bs5() ->
Const = mk_constant(),
Pairs = mk_pairs(),
true = are_same(Const, Pairs),
true = lists:all(fun ({B, L}) -> binary_to_list(B) =:= L end, Pairs),
ok.
are_same(C, L) ->
C =:= L.
mk_constant() ->
[{<<213>>,[213]},
{<<56>>,[56]},
{<<1,2>>,[1,2]},
{<<71>>,[71]},
{<<8,1>>,[8,1]},
{<<3,9>>,[3,9]},
{<<9,3>>,[9,3]},
{<<0,0,0,0>>,[0,0,0,0]},
{<<62,0,0,0>>,[62,0,0,0]},
{<<0,0,0,62>>,[0,0,0,62]},
{<<138,99,0,147>>,[138,99,0,147]},
{<<138,99,0,148>>,[138,99,0,148]},
{<<147,0,99,138>>,[147,0,99,138]},
{<<255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255>>,
[255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255]},
{<<13>>,[13]},
{<<0,4,0,5>>,[0,4,0,5]},
{<<129>>,[129]},
{<<129>>,[129]},
{<<1,2>>,[1,2]},
{<<1>>,[1]},
{<<4,3,1>>,[4,3,1]},
{<<47>>,[47]},
{<<>>,[]},
{<<97,112,97>>,[97,112,97]},
{<<46,110,142,77,45,204,233>>,[46,110,142,77,45,204,233]},
{<<>>,[]}].
mk_pairs() ->
L4 = [138,99,0,147],
[{<<-43>>,[256-43]},
{<<56>>,[56]},
{<<1,2>>,[1,2]},
{<<4:4,7:4>>,[4*16+7]},
{<<1:5,1:11>>,[1*8,1]},
{<<777:16/big>>,[3,9]},
{<<777:16/little>>,[9,3]},
{<<0.0:32/float>>,[0,0,0,0]},
{<<0.125:32/float>>,[62,0,0,0]},
{<<0.125:32/little-float>>,[0,0,0,62]},
{<<57285702734876389752897683:32>>,L4},
{<<57285702734876389752897684:32>>,[138,99,0,148]},
{<<57285702734876389752897683:32/little>>,lists:reverse(L4)},
{<<-1:17/unit:8>>,lists:duplicate(17,255)},
{<<13>>,[13]},
{<<4:8/unit:2,5:2/unit:8>>,[0,4,0,5]},
{<<1:1,0:6,1:1>>,[129]},
{<<1:1/little,0:6/little,1:1/little>>,[129]},
{<<<<1,2>>/binary>>,[1,2]},
{<<<<1,2>>:1/binary>>,[1]},
{<<4,3,<<1,2>>:1/binary>>,[4,3,1]},
{<<(256*45+47)>>,[47]},
{<<57:0>>,[]},
{<<"apa">>,"apa"},
{<<1:3,"string",9:5>>,[46,110,142,77,45,204,233]},
{<<>>,[]}].
%%--------------------------------------------------------------------
%% Constructs a big enough binary to have a bit size that needs a
%% bignum on 32-bit architectures
large_bin(X1, X2, X3, X4) ->
Sz = 16#4000000,
<<1, <<X1:Sz, X2:Sz, X3:Sz, X4:Sz>>/bits>>.
%%--------------------------------------------------------------------
%% Test construction of "bad" binaries
-define(FAIL(Expr), {'EXIT', {badarg, _}} = (catch Expr)).
bad_ones() ->
PI = math:pi(),
?FAIL(<<PI>>),
Bin12 = <<1,2>>,
?FAIL(<<Bin12>>),
E = 2.71,
?FAIL(<<E/binary>>),
Int = 24334,
?FAIL(<<Int/binary>>),
BigInt = 24334344294788947129487129487219847,
?FAIL(<<BigInt/binary>>),
Bin123 = <<1,2,3>>,
?FAIL(<<Bin123/float>>),
ok.
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