## Copyright (C) 2000, 2005, 2006, 2007, 2009 Paul Kienzle
## Copyright (C) 2003 Alois Schloegl
## Copyright (C) 2010 VZLU Prague
##
## 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.
##
## 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, see
## <http://www.gnu.org/licenses/>.

## -*- texinfo -*-
## @deftypefn {Function File} {} strmatch (@var{s}, @var{a}, "exact")
## Return indices of entries of @var{a} that match the string @var{s}.
## The second argument @var{a} may be a string matrix or a cell array of
## strings.  If the third argument @code{"exact"} is not given, then
## @var{s} only needs to match @var{a} up to the length of @var{s}.
## Trailing whitespace is ignored.
## Results are returned as a column vector. 
## For example:
##
## @example
## @group
## strmatch ("apple", "apple juice")
##      @result{} 1
##
## strmatch ("apple", ["apple pie"; "apple juice"; "an apple"])
##      @result{} [1; 2]
##
## strmatch ("apple", @{"apple pie"; "apple juice"; "tomato"@})
##      @result{} [1; 2]
## @end group
## @end example
## @seealso{strfind, findstr, strcmp, strncmp, strcmpi, strncmpi, find}
## @end deftypefn

## Author: Paul Kienzle, Alois Schloegl
## Adapted-by: jwe

function idx = strmatch (s, A, exact)

  if (nargin < 2 || nargin > 3)
    print_usage ();
  endif

  if (! ischar (s))
    error ("strmatch: first argument must be a string");
  endif
  
  ## Truncate trailing whitespace.
  s = strtrimr (s);

  len = length (s);

  exact = nargin == 3 && ischar (exact) && strcmp (exact, "exact");

  if (iscell (A))
    idx = find (strncmp (s, A, len));
    if (exact)
      ## We can't just use strcmp, because we need to ignore whitespace.
      B = cellfun (@strtrimr, A(idx), "uniformoutput", false);
      idx = idx (strcmp (s, B));
    endif
  elseif (ischar (A))
    [nr, nc] = size (A);
    if (len > nc)
      idx = [];
    else
      match = all (bsxfun (@eq, A(:,1:len), s), 2);
      if (exact)
        AA = A(:,len+1:nc);
        match &= all (AA == "\0" | AA == " ", 2);
      endif
      idx = find (match);
    endif
  else
    error ("strmatch: second argument must be a string or cell array of strings");
  endif
    
endfunction 

## Removes nuls and blanks from the end of the array
function s = strtrimr (s)
  blnks = s == "\0" | s == " ";
  i = find (blnks, 1, "last");
  if (i && all (blnks(i:end)))
    s = s(1:i-1);
  endif
endfunction

%!error <Invalid call to strmatch> strmatch();
%!error <Invalid call to strmatch> strmatch("a", "aaa", "exact", 1);
%!assert (strmatch("a", {"aaa", "bab", "bbb"}), 1);
%!assert (strmatch ("apple", "apple juice"), 1);
%!assert (strmatch ("apple", ["apple pie"; "apple juice"; "an apple"]),
%!        [1; 2]);
%!assert (strmatch ("apple", {"apple pie"; "apple juice"; "tomato"}),
%!        [1; 2]);
%!assert (strmatch ("apple pie", "apple"), []);
%!assert (strmatch ("a b", {"a b", "a c", "c d"}));