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##
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## distribution or <https://octave.org/copyright/>.
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## -*- texinfo -*-
## @deftypefn {} {[@var{style}, @var{color}, @var{marker}, @var{msg}] =} colstyle (@var{style})
## Parse the line specification @var{style} and return the line style, color,
## and markers given.
##
## In the case of an error, the string @var{msg} will return the text of the
## error.
## @end deftypefn

function [l, c, m, msg] = colstyle (style)

  if (nargin < 1)
    print_usage ();
  endif

  if (! ischar (style))
    error ("colstyle: STYLE must be a string");
  endif

  try
    opt = __pltopt__ ("colstyle", style);
    l = opt.linestyle;
    switch (opt.color)
      case [0 0 0]
        c = "k";
      case [1 0 0]
        c = "r";
      case [0 1 0]
        c = "g";
      case [0 0 1]
        c = "b";
      case [1 1 0]
        c = "y";
      case [1 0 1]
        c = "m";
      case [0 1 1]
        c = "c";
      case [0 1 1]
        c = "w";
      otherwise
        c = opt.color;
    endswitch
    m = opt.marker;
    msg = [];
  catch
    l = c = m = [];
    msg = lasterr ();
  end_try_catch

endfunction


%!test
%! [l, c, m, msg] = colstyle ("r:x");
%! assert (isempty (msg));
%! assert (l, ":");
%! assert (c, "r");
%! assert (m, "x");

%!test
%! [l, c, m, msg] = colstyle (".");
%! assert (isempty (msg));
%! assert (l, "none");
%! assert (c, []);
%! assert (m, ".");

%!test
%! [l, c, m, msg] = colstyle ("~");
%! assert (msg, "colstyle: unrecognized format character: '~'");

## Test input validation
%!error <Invalid call> colstyle ()
%!error colstyle (1, 2)
%!error <STYLE must be a string> colstyle (1.5)
