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## -*- texinfo -*-
## @deftypefn {} {@var{b} =} bitget (@var{A}, @var{n})
## Return the bit value at position(s) @var{n} of the unsigned integers in
## @var{A}.
##
## The least significant bit is @var{n} = 1.
##
## @example
## @group
## bitget (100, 8:-1:1)
## @xresult{} 0  1  1  0  0  1  0  0
## @end group
## @end example
## @seealso{bitand, bitor, bitxor, bitset, bitcmp, bitshift, intmax, flintmax}
## @end deftypefn

## Liberally based of the version by Kai Habel from Octave Forge

function b = bitget (A, n)

  if (nargin != 2)
    print_usage ();
  endif

  if (isa (A, "double"))
    Amax = ceil (log2 (flintmax));
    _conv = @double;
  elseif (isa (A, "single"))
    Amax = ceil (log2 (flintmax ("single")));
    _conv = @single;
  else
    if (isa (A, "uint8"))
      Amax = 8;
      _conv = @uint8;
    elseif (isa (A, "uint16"))
      Amax = 16;
      _conv = @uint16;
    elseif (isa (A, "uint32"))
      Amax = 32;
      _conv = @uint32;
    elseif (isa (A, "uint64"))
      Amax = 64;
      _conv = @uint64;
    ## Temporary fix for bug #67592 for Octave 11.
    ## Use unsigned integers in algorithm.
    elseif (isa (A, "int8"))
      Amax = 8;
      _conv = @uint8;
      A = typecast (A, 'uint8');
    elseif (isa (A, "int16"))
      Amax = 16;
      _conv = @uint16;
      A = typecast (A, 'uint16');
    elseif (isa (A, "int32"))
      Amax = 32;
      _conv = @uint32;
      A = typecast (A, 'uint32');
    elseif (isa (A, "int64"))
      Amax = 64;
      _conv = @uint64;
      A = typecast (A, 'uint64');
    else
      error ("bitget: invalid class %s", class (A));
    endif
  endif

  m = double (n(:));
  if (any (m < 1) || any (m > Amax))
    error ("bitget: N must be in the range [1,%d]", Amax);
  endif

  b = bitand (A, bitshift (_conv (1), uint8 (n) - uint8 (1))) != _conv (0);

endfunction


%!test
%! assert (bitget ([4, 14], [3, 3]), logical ([1, 1]));
%! assert (bitget (single ([4, 14]), [3, 3]), logical ([1, 1]));
%! pfx = {"", "u"};
%! for i = 1:2
%!   for prec = [8, 16, 32, 64]
%!     fcn = str2func (sprintf ("%sint%d", pfx{i}, prec));
%!     assert (bitget (fcn ([4, 14]), [3, 3]), logical ([1, 1]));
%!   endfor
%! endfor

%!test <*67592>
%! x = intmin ('int8');
%! b = bitget (x, 8:-1:1);
%! assert (b, logical ([1 0 0 0 0 0 0 0]));

## Test input validation
%!error <Invalid call> bitget ()
%!error <Invalid call> bitget (1)
%!error <invalid class> bitget ("char", 1)
%!error <N must be in the range \[1,53\]> bitget (0, 0)
%!error <N must be in the range \[1,53\]> bitget (0, 55)
%!error <N must be in the range \[1,24\]> bitget (single (0), 0)
%!error <N must be in the range \[1,24\]> bitget (single (0), 26)
%!error <N must be in the range \[1,8\]> bitget (int8 (0), 9)
%!error <N must be in the range \[1,8\]> bitget (uint8 (0), 9)
%!error <N must be in the range \[1,16\]> bitget (int16 (0), 17)
%!error <N must be in the range \[1,16\]> bitget (uint16 (0), 17)
%!error <N must be in the range \[1,32\]> bitget (int32 (0), 33)
%!error <N must be in the range \[1,32\]> bitget (uint32 (0), 33)
%!error <N must be in the range \[1,64\]> bitget (int64 (0), 65)
%!error <N must be in the range \[1,64\]> bitget (uint64 (0), 65)
