%% -*- erlang-indent-level: 2 -*-
%%--------------------------------------------------------------------
%%  Author  : Kostis Sagonas
%%  Purpose : These tests are intended to test the construction and
%%            matching of binaries using variable sizes
%%  Notes   :
%%   - Added test that crashed BEAM compiler
%%   - Added test that crashed when segments of size zero were used
%%     and one that did not convert integers to floats when constructing
%%     binaries.
%%   - Added a construction test which crashed from core because of
%%     problems with the effect flag (2004/11/15)
%%--------------------------------------------------------------------
-module(bs_var_segs).

-export([test/0]).

test() ->
  N1 = 18,
  A1 = 2,
  A1 = match1(N1, <<1:12, 2:N1, A1:2>>),
  A1 = match2(N1, <<1:12, 2:N1/integer-little, A1:2>>),
  N3 = 3,
  A3 = <<1,2,3>>,
  B3 = 2,
  {A3, B3} = match3(N3, <<1:12, A3:N3/binary, B3:4>>),
  N4 = 12,
  B4 = <<1,2,3>>,
  A4 = 2,
  {A4, B4} = match4(N4, <<1:N4, A4:4, B4/binary>>),
  Y = <<5>>,
  Y = match5(a, Y),
  <<73>> = gen1(8, 0, <<73>>),
  <<171>> = gen2(8, 7, 2#10101010101010101),
  <<0:64>> = construct(),
  <<0:32>> = construct2(0),
  ok = in_guard(<<16#BCD:14,3:2>>, 16#BCD),
  ok.

construct() ->
  <<0:64/float>>.

construct2(X) ->
  <<X:32/little>>.

match1(N, Bin) ->
  <<1:12, 2:N, A:2>>=Bin,
  A.

match2(N, Bin) ->
  <<1:12, 2:N/integer-little, A:2>>=Bin,
  A.

match3(N, Bin) ->
  <<1:12, A:N/binary, B:4>>=Bin,
  {A,B}.

match4(N, Bin) ->
  <<1:N, A:4, B/binary>>=Bin,
  {A,B}.

match5(X, Y) ->
  case X of
    a ->
      Y2 = 8
  end,
  <<5:Y2>> = Y.

gen1(N, S, A) ->
  <<A:S/binary-unit:1, A:(N-S)/binary-unit:1>>.

gen2(N, S, A) ->
  <<A:S/little, A:(N-S)/little>>.

in_guard(Bin, A) when <<A:14,3:2>> == Bin -> ok;
in_guard(_, _) -> no.