########################################################################
##
## Copyright (C) 2007-2022 The Octave Project Developers
##
## See the file COPYRIGHT.md in the top-level directory of this
## distribution or <https://octave.org/copyright/>.
##
## This file is part of Octave.
##
## Octave is free software: you can redistribute it and/or modify it
## under the terms of the GNU General Public License as published by
## the Free Software Foundation, either version 3 of the License, or
## (at your option) any later version.
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## WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
## GNU General Public License for more details.
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## You should have received a copy of the GNU General Public License
## along with Octave; see the file COPYING.  If not, see
## <https://www.gnu.org/licenses/>.
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########################################################################

## -*- texinfo -*-
## @deftypefn  {} {@var{str} =} strjoin (@var{cstr})
## @deftypefnx {} {@var{str} =} strjoin (@var{cstr}, @var{delimiter})
## Join the elements of the cell string array, @var{cstr}, into a single
## string.
##
## If no @var{delimiter} is specified, the elements of @var{cstr} are
## separated by a space.
##
## If @var{delimiter} is specified as a string, the cell string array is
## joined using the string.  Escape sequences are supported.
##
## If @var{delimiter} is a cell string array whose length is one less than
## @var{cstr}, then the elements of @var{cstr} are joined by interleaving the
## cell string elements of @var{delimiter}.  Escape sequences are not
## supported.
##
## @example
## @group
## strjoin (@{'Octave','Scilab','Lush','Yorick'@}, '*')
##       @result{} 'Octave*Scilab*Lush*Yorick'
## @end group
## @end example
## @seealso{strsplit}
## @end deftypefn

function rval = strjoin (cstr, delimiter = " ")

  if (nargin < 1)
    print_usage ();
  elseif (! (iscellstr (cstr) && (ischar (delimiter) || iscellstr (delimiter))))
    print_usage ();
  endif

  if (numel (cstr) == 1)
    rval = cstr{1};
    return;
  endif

  if (ischar (delimiter))
    delimiter = do_string_escapes (delimiter);
    delimiter = {delimiter};
  endif

  num = numel (cstr);
  if (numel (delimiter) == 1 && num > 1)
    delimiter = repmat (delimiter, 1, num);
    delimiter(end) = {""};
  elseif (num > 0 && numel (delimiter) != num - 1)
    error ("Octave:strjoin:cellstring_delimiter_mismatch",
      "strjoin: the number of delimiters does not match the number of strings");
  else
    delimiter(end+1) = {""};
  endif

  if (num == 0)
    rval = "";
  else
    rval = [[cstr(:).'; delimiter(:).']{:}];
  endif

endfunction


%!assert (strjoin ({"hello"}, "-"), "hello")
%!assert (strjoin ({"hello", "world"}), "hello world")
%!assert (strjoin ({"Octave", "Scilab", "Lush", "Yorick"}, "*"),
%!  "Octave*Scilab*Lush*Yorick")
%!assert (strjoin ({"space", "comma", "dash", "semicolon", "done"},
%!  {" ", ",", "-", ";"}), "space comma,dash-semicolon;done")
%!assert (strjoin ({'Octave','Scilab'},'\n'), "Octave\nScilab")
%!assert (strjoin ({'Octave','Scilab'},{'\n'}), "Octave\\nScilab")
%!assert (strjoin ({},'foo'), "")