## Copyright (C) 2000  Etienne Grossmann
##
## 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 2, or (at your option)
## any later version.
##
## Octave is distributed in the hope that it will be useful, but
## 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.
##
## You should have received a copy of the GNU General Public License
## along with Octave; see the file COPYING.  If not, write to the Free
## Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
## 02110-1301, USA.

## -*- texinfo -*-
## @deftypefn {Function File} {[@var{v1}, @dots{}] =} getfield (@var{s}, @var{key}, @dots{}) 
## Extract fields from a structure. For example
##
## @example
## @group
## ss(1,2).fd(3).b=5;
## getfield (ss, @{1,2@}, "fd", @{3@}, "b")
## @result{} ans = 5
## @end group
## @end example
##
## Note that the function call in the previous example is equivalent to
## the expression
##
## @example
##          i1= @{1,2@}; i2= "fd"; i3= @{3@}; i4= "b";
##          ss(i1@{:@}).(i2)(i3@{:@}).(i4)
## @end example
## @seealso{setfield, rmfield, isfield, isstruct, fieldnames, struct}
## @end deftypefn

## Author: Etienne Grossmann <etienne@cs.uky.edu>

function s = getfield (s, varargin)

  for idx = 1:nargin-1
    i = varargin{idx};
    if (iscell (i))
      s = s(i{:});
    else
      s = s.(i);
    endif
  endfor

endfunction

%!test
%! x.a = "hello";
%! assert(getfield(x,"a"),"hello");
%!test
%! ss(1,2).fd(3).b = 5;
%! assert(getfield(ss,{1,2},'fd',{3},'b'),5)