/*

Copyright (C) 2005-2012 David Bateman
Copyright (C) 2002-2005 Paul Kienzle

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/>.

*/

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <list>
#include <sstream>

#include <pcre.h>

#include "base-list.h"
#include "oct-locbuf.h"
#include "quit.h"
#include "regexp.h"
#include "str-vec.h"

#include "defun-dld.h"
#include "Cell.h"
#include "error.h"
#include "gripes.h"
#include "oct-map.h"
#include "oct-obj.h"
#include "utils.h"

static void
parse_options (regexp::opts& options, const octave_value_list& args,
               const std::string& who, int skip, bool& extra_args)
{
  int nargin = args.length ();

  extra_args = false;

  for (int i = skip; i < nargin; i++)
    {
      std::string str = args(i).string_value ();

      if (error_state)
        {
          error ("%s: optional arguments must be character strings",
                 who.c_str ());
          break;
        }

      std::transform (str.begin (), str.end (), str.begin (), tolower);

      if (str.find ("once", 0) == 0)
        options.once (true);
      else if (str.find ("matchcase", 0) == 0)
        options.case_insensitive (false);
      else if (str.find ("ignorecase", 0) == 0)
        options.case_insensitive (true);
      else if (str.find ("dotall", 0) == 0)
        options.dotexceptnewline (false);
      else if (str.find ("stringanchors", 0) == 0)
        options.lineanchors (false);
      else if (str.find ("literalspacing", 0) == 0)
        options.freespacing (false);
      else if (str.find ("dotexceptnewline", 0) == 0)
        options.dotexceptnewline (true);
      else if (str.find ("lineanchors", 0) == 0)
        options.lineanchors (true);
      else if (str.find ("freespacing", 0) == 0)
        options.freespacing (true);
      else if (str.find ("start", 0) == 0
               || str.find ("end", 0) == 0
               || str.find ("tokenextents", 0) == 0
               || str.find ("match", 0) == 0
               || str.find ("tokens", 0) == 0
               || str.find ("names", 0) == 0
               || str.find ("split", 0) == 0)
        extra_args = true;
      else
        error ("%s: unrecognized option", who.c_str ());
    }
}

static octave_value_list
octregexp (const octave_value_list &args, int nargout,
           const std::string &who, bool case_insensitive = false)
{
  octave_value_list retval;

  int nargin = args.length ();

  // Make sure we have string, pattern
  const std::string buffer = args(0).string_value ();
  if (error_state)
    return retval;

  const std::string pattern = args(1).string_value ();
  if (error_state)
    return retval;

  regexp::opts options;
  options.case_insensitive (case_insensitive);
  bool extra_options = false;
  parse_options (options, args, who, 2, extra_options);
  if (error_state)
    return retval;

  regexp::match_data rx_lst = regexp_match (pattern, buffer, options, who);

  string_vector named_pats = rx_lst.named_patterns ();

  size_t sz = rx_lst.size ();

  if (! error_state)
    {
      // Converted the linked list in the correct form for the return values

      octave_idx_type i = 0;
      octave_scalar_map nmap;

      retval.resize (7);

      if (sz == 1)
        {
          string_vector named_tokens = rx_lst.begin()->named_tokens ();

          for (int j = 0; j < named_pats.length (); j++)
            nmap.assign (named_pats(j), named_tokens(j));

          retval(5) = nmap;
        }
      else
        {
          for (int j = 0; j < named_pats.length (); j++)
            {
              Cell tmp (dim_vector (1, sz));

              i = 0;
              for (regexp::match_data::const_iterator p = rx_lst.begin ();
                   p != rx_lst.end (); p++)
                {
                  string_vector named_tokens = p->named_tokens ();

                  tmp(i++) = named_tokens(j);
                }

              nmap.assign (named_pats(j), octave_value (tmp));
            }

          retval(5) = nmap;
        }

      if (options.once ())
        {
          regexp::match_data::const_iterator p = rx_lst.begin ();

          retval(4) = sz ? p->tokens () : Cell ();
          retval(3) = sz ? p->match_string () : std::string ();
          retval(2) = sz ? p->token_extents () : Matrix ();

          if (sz)
            {
              double start = p->start ();
              double end = p->end ();

              Cell split (dim_vector (1, 2));
              split(0) = buffer.substr (0, start-1);
              split(1) = buffer.substr (end);

              retval(6) = split;
              retval(1) = end;
              retval(0) = start;
            }
          else
            {
              retval(6) = buffer;
              retval(1) = Matrix ();
              retval(0) = Matrix ();
            }
        }
      else
        {
          Cell tokens (dim_vector (1, sz));
          Cell match_string (dim_vector (1, sz));
          Cell token_extents (dim_vector (1, sz));
          NDArray end (dim_vector (1, sz));
          NDArray start (dim_vector (1, sz));
          Cell split (dim_vector (1, sz+1));
          size_t sp_start = 0;

          i = 0;
          for (regexp::match_data::const_iterator p = rx_lst.begin ();
               p != rx_lst.end (); p++)
            {
              double s = p->start ();
              double e = p->end ();

              string_vector tmp = p->tokens ();
              tokens(i) = Cell (dim_vector (1, tmp.length ()), tmp);
              match_string(i) = p->match_string ();
              token_extents(i) = p->token_extents ();
              end(i) = e;
              start(i) = s;
              split(i) = buffer.substr (sp_start, s-sp_start-1);
              sp_start = e;
              i++;
            }

          split(i) = buffer.substr (sp_start);

          retval(6) = split;
          retval(4) = tokens;
          retval(3) = match_string;
          retval(2) = token_extents;
          retval(1) = end;
          retval(0) = start;
        }

      // Alter the order of the output arguments

      if (extra_options)
        {
          int n = 0;
          octave_value_list new_retval;
          new_retval.resize (nargout);

          OCTAVE_LOCAL_BUFFER (int, arg_used, 6);
          for (int j = 0; j < 6; j++)
            arg_used[j] = false;

          for (int j = 2; j < nargin; j++)
            {
              int k = 0;
              std::string str = args(j).string_value ();
              std::transform (str.begin (), str.end (), str.begin (), tolower);

              if (str.find ("once", 0) == 0
                  || str.find ("stringanchors", 0) == 0
                  || str.find ("lineanchors", 0) == 0
                  || str.find ("matchcase", 0) == 0
                  || str.find ("ignorecase", 0) == 0
                  || str.find ("dotall", 0) == 0
                  || str.find ("dotexceptnewline", 0) == 0
                  || str.find ("literalspacing", 0) == 0
                  || str.find ("freespacing", 0) == 0)
                continue;
              else if (str.find ("start", 0) == 0)
                k = 0;
              else if (str.find ("end", 0) == 0)
                k = 1;
              else if (str.find ("tokenextents", 0) == 0)
                k = 2;
              else if (str.find ("match", 0) == 0)
                k = 3;
              else if (str.find ("tokens", 0) == 0)
                k = 4;
              else if (str.find ("names", 0) == 0)
                k = 5;
              else if (str.find ("split", 0) == 0)
                k = 6;

              new_retval(n++) = retval(k);
              arg_used[k] = true;

              if (n == nargout)
                break;
            }

          // Fill in the rest of the arguments
          if (n < nargout)
            {
              for (int j = 0; j < 6; j++)
                {
                  if (! arg_used[j])
                    new_retval(n++) = retval(j);
                }
            }

          retval = new_retval;
        }
    }

  return retval;
}

static octave_value_list
octcellregexp (const octave_value_list &args, int nargout,
               const std::string &who, bool case_insensitive = false)
{
  octave_value_list retval;

  if (args(0).is_cell ())
    {
      OCTAVE_LOCAL_BUFFER (Cell, newretval, nargout);
      octave_value_list new_args = args;
      Cell cellstr = args(0).cell_value ();
      if (args(1).is_cell ())
        {
          Cell cellpat = args(1).cell_value ();

          if (cellpat.numel () == 1)
            {
              for (int j = 0; j < nargout; j++)
                newretval[j].resize (cellstr.dims ());

              new_args(1) = cellpat(0);

              for (octave_idx_type i = 0; i < cellstr.numel (); i++)
                {
                  new_args(0) = cellstr(i);
                  octave_value_list tmp = octregexp (new_args, nargout, who,
                                                     case_insensitive);

                  if (error_state)
                    break;

                  for (int j = 0; j < nargout; j++)
                    newretval[j](i) = tmp(j);
                }
            }
          else if (cellstr.numel () == 1)
            {
              for (int j = 0; j < nargout; j++)
                newretval[j].resize (cellpat.dims ());

              new_args(0) = cellstr(0);

              for (octave_idx_type i = 0; i < cellpat.numel (); i++)
                {
                  new_args(1) = cellpat(i);
                  octave_value_list tmp = octregexp (new_args, nargout, who,
                                                     case_insensitive);

                  if (error_state)
                    break;

                  for (int j = 0; j < nargout; j++)
                    newretval[j](i) = tmp(j);
                }
            }
          else if (cellstr.numel () == cellpat.numel ())
            {

              if (cellstr.dims () != cellpat.dims ())
                error ("%s: inconsistent cell array dimensions", who.c_str ());
              else
                {
                  for (int j = 0; j < nargout; j++)
                    newretval[j].resize (cellstr.dims ());

                  for (octave_idx_type i = 0; i < cellstr.numel (); i++)
                    {
                      new_args(0) = cellstr(i);
                      new_args(1) = cellpat(i);

                      octave_value_list tmp = octregexp (new_args, nargout, who,
                                                         case_insensitive);

                      if (error_state)
                        break;

                      for (int j = 0; j < nargout; j++)
                        newretval[j](i) = tmp(j);
                    }
                }
            }
          else
            error ("regexp: cell array arguments must be scalar or equal size");
        }
      else
        {
          for (int j = 0; j < nargout; j++)
            newretval[j].resize (cellstr.dims ());

          for (octave_idx_type i = 0; i < cellstr.numel (); i++)
            {
              new_args(0) = cellstr(i);
              octave_value_list tmp = octregexp (new_args, nargout, who,
                                                 case_insensitive);

              if (error_state)
                break;

              for (int j = 0; j < nargout; j++)
                newretval[j](i) = tmp(j);
            }
        }

      if (!error_state)
        for (int j = 0; j < nargout; j++)
          retval(j) = octave_value (newretval[j]);
    }
  else if (args(1).is_cell ())
    {
      OCTAVE_LOCAL_BUFFER (Cell, newretval, nargout);
      octave_value_list new_args = args;
      Cell cellpat = args(1).cell_value ();

      for (int j = 0; j < nargout; j++)
        newretval[j].resize(cellpat.dims ());

      for (octave_idx_type i = 0; i < cellpat.numel (); i++)
        {
          new_args(1) = cellpat(i);
          octave_value_list tmp = octregexp (new_args, nargout, who,
                                             case_insensitive);

          if (error_state)
            break;

          for (int j = 0; j < nargout; j++)
            newretval[j](i) = tmp(j);
        }

      if (!error_state)
        {
          for (int j = 0; j < nargout; j++)
            retval(j) = octave_value (newretval[j]);
        }
    }
  else
    retval = octregexp (args, nargout, who, case_insensitive);

  return retval;

}

DEFUN_DLD (regexp, args, nargout,
  "-*- texinfo -*-\n\
@deftypefn  {Loadable Function} {[@var{s}, @var{e}, @var{te}, @var{m}, @var{t}, @var{nm}] =} regexp (@var{str}, @var{pat})\n\
@deftypefnx {Loadable Function} {[@dots{}] =} regexp (@var{str}, @var{pat}, \"@var{opt1}\", @dots{})\n\
Regular expression string matching.  Search for @var{pat} in @var{str} and\n\
return the positions and substrings of any matches, or empty values if there\n\
are none.\n\
\n\
The matched pattern @var{pat} can include any of the standard regex\n\
operators, including:\n\
\n\
@table @code\n\
@item .\n\
Match any character\n\
\n\
@item * + ? @{@}\n\
Repetition operators, representing\n\
@table @code\n\
@item *\n\
Match zero or more times\n\
\n\
@item +\n\
Match one or more times\n\
\n\
@item ?\n\
Match zero or one times\n\
\n\
@item @{@var{n}@}\n\
Match exactly @var{n} times\n\
\n\
@item @{@var{n},@}\n\
Match @var{n} or more times\n\
\n\
@item @{@var{m},@var{n}@}\n\
Match between @var{m} and @var{n} times\n\
@end table\n\
\n\
@item [@dots{}] [^@dots{}]\n\
\n\
List operators.  The pattern will match any character listed between \"[\"\n\
and \"]\".  If the first character is \"^\" then the pattern is inverted and\n\
any character except those listed between brackets will match.\n\
\n\
Escape sequences defined below can also be used inside list\n\
operators.  For example, a template for a floating point number might be\n\
@code{[-+.\\d]+}.\n\
\n\
@item ()\n\
Grouping operator\n\
\n\
@item |\n\
Alternation operator.  Match one of a choice of regular expressions.  The\n\
alternatives must be delimited by the grouping operator @code{()} above.\n\
\n\
@item ^ $\n\
Anchoring operators.  Requires pattern to occur at the start (@code{^}) or\n\
end (@code{$}) of the string.\n\
@end table\n\
\n\
In addition, the following escaped characters have special meaning.  Note,\n\
it is recommended to quote @var{pat} in single quotes, rather than double\n\
quotes, to avoid the escape sequences being interpreted by Octave before\n\
being passed to @code{regexp}.\n\
\n\
@table @code\n\
@item \\b\n\
Match a word boundary\n\
\n\
@item \\B\n\
Match within a word\n\
\n\
@item \\w\n\
Match any word character\n\
\n\
@item \\W\n\
Match any non-word character\n\
\n\
@item \\<\n\
Match the beginning of a word\n\
\n\
@item \\>\n\
Match the end of a word\n\
\n\
@item \\s\n\
Match any whitespace character\n\
\n\
@item \\S\n\
Match any non-whitespace character\n\
\n\
@item \\d\n\
Match any digit\n\
\n\
@item \\D\n\
Match any non-digit\n\
@end table\n\
\n\
The outputs of @code{regexp} default to the order given below\n\
\n\
@table @var\n\
@item s\n\
The start indices of each matching substring\n\
\n\
@item e\n\
The end indices of each matching substring\n\
\n\
@item te\n\
The extents of each matched token surrounded by @code{(@dots{})} in\n\
@var{pat}\n\
\n\
@item m\n\
A cell array of the text of each match\n\
\n\
@item t\n\
A cell array of the text of each token matched\n\
\n\
@item nm\n\
A structure containing the text of each matched named token, with the name\n\
being used as the fieldname.  A named token is denoted by\n\
@code{(?<name>@dots{})}.\n\
\n\
@item sp\n\
A cell array of the text not returned by match.\n\
@end table\n\
\n\
Particular output arguments, or the order of the output arguments, can be\n\
selected by additional @var{opt} arguments.  These are strings and the\n\
correspondence between the output arguments and the optional argument\n\
are\n\
\n\
@multitable @columnfractions 0.2 0.3 0.3 0.2\n\
@item @tab 'start'        @tab @var{s}  @tab\n\
@item @tab 'end'          @tab @var{e}  @tab\n\
@item @tab 'tokenExtents' @tab @var{te} @tab\n\
@item @tab 'match'        @tab @var{m}  @tab\n\
@item @tab 'tokens'       @tab @var{t}  @tab\n\
@item @tab 'names'        @tab @var{nm} @tab\n\
@item @tab 'split'        @tab @var{sp} @tab\n\
@end multitable\n\
\n\
Additional arguments are summarized below.\n\
\n\
@table @samp\n\
@item once\n\
Return only the first occurrence of the pattern.\n\
\n\
@item matchcase\n\
Make the matching case sensitive.  (default)\n\
\n\
Alternatively, use (?-i) in the pattern.\n\
\n\
@item ignorecase\n\
Ignore case when matching the pattern to the string.\n\
\n\
Alternatively, use (?i) in the pattern.\n\
\n\
@item stringanchors\n\
Match the anchor characters at the beginning and end of the string.\n\
(default)\n\
\n\
Alternatively, use (?-m) in the pattern.\n\
\n\
@item lineanchors\n\
Match the anchor characters at the beginning and end of the line.\n\
\n\
Alternatively, use (?m) in the pattern.\n\
\n\
@item dotall\n\
The pattern @code{.} matches all characters including the newline character.\n\
 (default)\n\
\n\
Alternatively, use (?s) in the pattern.\n\
\n\
@item dotexceptnewline\n\
The pattern @code{.} matches all characters except the newline character.\n\
\n\
Alternatively, use (?-s) in the pattern.\n\
\n\
@item literalspacing\n\
All characters in the pattern, including whitespace, are significant and are\n\
used in pattern matching.  (default)\n\
\n\
Alternatively, use (?-x) in the pattern.\n\
\n\
@item freespacing\n\
The pattern may include arbitrary whitespace and also comments beginning with\n\
the character @samp{#}.\n\
\n\
Alternatively, use (?x) in the pattern.\n\
\n\
@end table\n\
@seealso{regexpi, strfind, regexprep}\n\
@end deftypefn")
{
  octave_value_list retval;

  int nargin = args.length ();

  if (nargin < 2)
    print_usage ();
  else if (args(0).is_cell () || args(1).is_cell ())
    retval = octcellregexp (args, nargout, "regexp");
  else
    retval = octregexp (args, nargout, "regexp");

  return retval;
}

/*

## PCRE_ERROR_MATCHLIMIT test
%!test
%! s=sprintf('\t4\n0000\t-0.00\t-0.0000\t4\t-0.00\t-0.0000\t4\n0000\t-0.00\t-0.0000\t0\t-0.00\t-');
%! ws = warning("query");
%! unwind_protect
%!   warning("off");
%!   regexp(s, '(\s*-*\d+[.]*\d*\s*)+\n');
%! unwind_protect_cleanup
%!   warning(ws);
%! end_unwind_protect

## seg-fault test
%!assert(regexp("abcde","."),[1,2,3,4,5])
## Infinite loop test
%!assert (isempty (regexp("abcde", "")))

## Check that anchoring of pattern works correctly
%!assert(regexp('abcabc','^abc'),1);
%!assert(regexp('abcabc','abc$'),4);
%!assert(regexp('abcabc','^abc$'),zeros(1,0));

%!test
%! [s, e, te, m, t] = regexp(' No Match ', 'f(.*)uck');
%! assert (s,zeros(1,0))
%! assert (e,zeros(1,0))
%! assert (te,cell(1,0))
%! assert (m, cell(1,0))
%! assert (t, cell(1,0))

%!test
%! [s, e, te, m, t] = regexp(' FiRetrUck ', 'f(.*)uck');
%! assert (s,zeros(1,0))
%! assert (e,zeros(1,0))
%! assert (te,cell(1,0))
%! assert (m, cell(1,0))
%! assert (t, cell(1,0))

%!test
%! [s, e, te, m, t] = regexp(' firetruck ', 'f(.*)uck');
%! assert (s,2)
%! assert (e,10)
%! assert (te{1},[3,7])
%! assert (m{1}, 'firetruck')
%! assert (t{1}{1}, 'iretr')

%!test
%! [s, e, te, m, t] = regexp('short test string','\w*r\w*');
%! assert (s,[1,12])
%! assert (e,[5,17])
%! assert (size(te), [1,2])
%! assert (isempty(te{1}))
%! assert (isempty(te{2}))
%! assert (m{1},'short')
%! assert (m{2},'string')
%! assert (size(t), [1,2])
%! assert (isempty(t{1}))
%! assert (isempty(t{2}))

%!test
%! [s, e, te, m, t] = regexp('short test string','\w*r\w*','once');
%! assert (s,1)
%! assert (e,5)
%! assert (isempty(te))
%! assert (m,'short')
%! assert (isempty(t))

%!test
%! [m, te, e, s, t] = regexp('short test string','\w*r\w*','once', 'match', 'tokenExtents', 'end', 'start', 'tokens');
%! assert (s,1)
%! assert (e,5)
%! assert (isempty(te))
%! assert (m,'short')
%! assert (isempty(t))

%!test
%! [s, e, te, m, t, nm] = regexp('short test string','(?<word1>\w*t)\s*(?<word2>\w*t)');
%! assert (s,1)
%! assert (e,10)
%! assert (size(te), [1,1])
%! assert (te{1}, [1 5; 7, 10])
%! assert (m{1},'short test')
%! assert (size(t),[1,1])
%! assert (t{1}{1},'short')
%! assert (t{1}{2},'test')
%! assert (size(nm), [1,1])
%! assert (!isempty(fieldnames(nm)))
%! assert (sort(fieldnames(nm)),{'word1';'word2'})
%! assert (nm.word1,'short')
%! assert (nm.word2,'test')

%!test
%! [nm, m, te, e, s, t] = regexp('short test string','(?<word1>\w*t)\s*(?<word2>\w*t)', 'names', 'match', 'tokenExtents', 'end', 'start', 'tokens');
%! assert (s,1)
%! assert (e,10)
%! assert (size(te), [1,1])
%! assert (te{1}, [1 5; 7, 10])
%! assert (m{1},'short test')
%! assert (size(t),[1,1])
%! assert (t{1}{1},'short')
%! assert (t{1}{2},'test')
%! assert (size(nm), [1,1])
%! assert (!isempty(fieldnames(nm)))
%! assert (sort(fieldnames(nm)),{'word1';'word2'})
%! assert (nm.word1,'short')
%! assert (nm.word2,'test')

%!test
%! [t, nm] = regexp("John Davis\nRogers, James",'(?<first>\w+)\s+(?<last>\w+)|(?<last>\w+),\s+(?<first>\w+)','tokens','names');
%! assert (size(t), [1,2]);
%! assert (t{1}{1},'John');
%! assert (t{1}{2},'Davis');
%! assert (t{2}{1},'Rogers');
%! assert (t{2}{2},'James');
%! assert (size(nm), [1,1]);
%! assert (nm.first{1},'John');
%! assert (nm.first{2},'James');
%! assert (nm.last{1},'Davis');
%! assert (nm.last{2},'Rogers');

%!test
%! # Parenthesis in named token (ie (int)) causes a problem
%! assert (regexp('qwe int asd', ['(?<typestr>(int))'], 'names'), struct ('typestr', 'int'));

%!assert(regexp("abc\nabc",'.'),[1:7])
%!assert(regexp("abc\nabc",'.','dotall'),[1:7])
%!test
%! assert(regexp("abc\nabc",'(?s).'),[1:7])
%! assert(regexp("abc\nabc",'.','dotexceptnewline'),[1,2,3,5,6,7])
%! assert(regexp("abc\nabc",'(?-s).'),[1,2,3,5,6,7])

%!assert(regexp("caseCaSe",'case'),1)
%!assert(regexp("caseCaSe",'case',"matchcase"),1)
%!assert(regexp("caseCaSe",'case',"ignorecase"),[1,5])
%!test
%! assert(regexp("caseCaSe",'(?-i)case'),1)
%! assert(regexp("caseCaSe",'(?i)case'),[1,5])

%!assert (regexp("abc\nabc",'c$'),7)
%!assert (regexp("abc\nabc",'c$',"stringanchors"),7)
%!test
%! assert (regexp("abc\nabc",'(?-m)c$'),7)
%! assert (regexp("abc\nabc",'c$',"lineanchors"),[3,7])
%! assert (regexp("abc\nabc",'(?m)c$'),[3,7])

%!assert (regexp("this word",'s w'),4)
%!assert (regexp("this word",'s w','literalspacing'),4)
%!test
%! assert (regexp("this word",'(?-x)s w','literalspacing'),4)
%! assert (regexp("this word",'s w','freespacing'),zeros(1,0))
%! assert (regexp("this word",'(?x)s w'),zeros(1,0))

%!error regexp('string', 'tri', 'BadArg');
%!error regexp('string');

%!assert(regexp({'asdfg-dfd';'-dfd-dfd-';'qasfdfdaq'},'-'),{6;[1,5,9];zeros(1,0)})
%!assert(regexp({'asdfg-dfd','-dfd-dfd-','qasfdfdaq'},'-'),{6,[1,5,9],zeros(1,0)})
%!assert(regexp({'asdfg-dfd';'-dfd-dfd-';'qasfdfdaq'},{'-';'f';'q'}),{6;[3,7];[1,9]})
%!assert(regexp('Strings',{'t','s'}),{2,7})

## Test case for lookaround operators
%!test
%! assert(regexp('Iraq','q(?!u)'),4)
%! assert(regexp('quit','q(?!u)'), zeros(1,0))
%! assert(regexp('quit','q(?=u)','match'), {'q'})
%! assert(regexp("quit",'q(?=u+)','match'), {'q'})
%! assert(regexp("qit",'q(?=u+)','match'), cell(1,0))
%! assert(regexp("qit",'q(?=u*)','match'), {'q'})
%! assert(regexp('thingamabob','(?<=a)b'), 9)

## Tests for split option.
%!shared str
%! str = "foo bar foo";
%!test
%! [a, b] = regexp (str, "f..", "match", "split");
%! assert (a, {"foo", "foo"});
%! assert (b, {"", " bar ", ""});
%!test
%! [a, b] = regexp (str, "f..", "match", "split", "once");
%! assert (a, "foo");
%! assert (b, {"", " bar foo"});
%!test
%! [a, b] = regexp (str, "fx.", "match", "split");
%! assert (a, cell (1, 0));
%! assert (b, {"foo bar foo"});
%!test
%! [a, b] = regexp (str, "fx.", "match", "split", "once");
%! assert (a, "");
%! assert (b, "foo bar foo")

%!shared str
%! str = "foo bar";
%!test
%! [a, b] = regexp (str, "f..", "match", "split");
%! assert (a, {"foo"});
%! assert (b, {"", " bar"});
%!test
%! [a, b] = regexp (str, "b..", "match", "split");
%! assert (a, {"bar"});
%! assert (b, {"foo ", ""});
%!test
%! [a, b] = regexp (str, "x", "match", "split");
%! assert (a, cell (1, 0));
%! assert (b, {"foo bar"});
%!test
%! [a, b] = regexp (str, "[o]+", "match", "split");
%! assert (a, {"oo"});
%! assert (b, {"f", " bar"});

*/

DEFUN_DLD (regexpi, args, nargout,
  "-*- texinfo -*-\n\
@deftypefn  {Loadable Function} {[@var{s}, @var{e}, @var{te}, @var{m}, @var{t}, @var{nm}] =} regexpi (@var{str}, @var{pat})\n\
@deftypefnx {Loadable Function} {[@dots{}] =} regexpi (@var{str}, @var{pat}, \"@var{opt1}\", @dots{})\n\
\n\
Case insensitive regular expression string matching.  Search for @var{pat} in\n\
@var{str} and return the positions and substrings of any matches, or empty\n\
values if there are none.  @xref{doc-regexp,,regexp}, for details on the\n\
syntax of the search pattern.\n\
@seealso{regexp}\n\
@end deftypefn")
{
  octave_value_list retval;

  int nargin = args.length ();

  if (nargin < 2)
    print_usage ();
  else if (args(0).is_cell () || args(1).is_cell ())
    retval = octcellregexp (args, nargout, "regexpi", true);
  else
    retval = octregexp (args, nargout, "regexpi", true);

  return retval;
}

/*

## seg-fault test
%!assert(regexpi("abcde","."),[1,2,3,4,5])

## Check that anchoring of pattern works correctly
%!assert(regexpi('abcabc','^ABC'),1);
%!assert(regexpi('abcabc','ABC$'),4);
%!assert(regexpi('abcabc','^ABC$'),zeros(1,0));

%!test
%! [s, e, te, m, t] = regexpi(' No Match ', 'f(.*)uck');
%! assert (s,zeros(1,0))
%! assert (e,zeros(1,0))
%! assert (te,cell(1,0))
%! assert (m, cell(1,0))
%! assert (t, cell(1,0))

%!test
%! [s, e, te, m, t] = regexpi(' FiRetrUck ', 'f(.*)uck');
%! assert (s,2)
%! assert (e,10)
%! assert (te{1},[3,7])
%! assert (m{1}, 'FiRetrUck')
%! assert (t{1}{1}, 'iRetr')

%!test
%! [s, e, te, m, t] = regexpi(' firetruck ', 'f(.*)uck');
%! assert (s,2)
%! assert (e,10)
%! assert (te{1},[3,7])
%! assert (m{1}, 'firetruck')
%! assert (t{1}{1}, 'iretr')

%!test
%! [s, e, te, m, t] = regexpi('ShoRt Test String','\w*r\w*');
%! assert (s,[1,12])
%! assert (e,[5,17])
%! assert (size(te), [1,2])
%! assert (isempty(te{1}))
%! assert (isempty(te{2}))
%! assert (m{1},'ShoRt')
%! assert (m{2},'String')
%! assert (size(t), [1,2])
%! assert (isempty(t{1}))
%! assert (isempty(t{2}))

%!test
%! [s, e, te, m, t] = regexpi('ShoRt Test String','\w*r\w*','once');
%! assert (s,1)
%! assert (e,5)
%! assert (isempty(te))
%! assert (m,'ShoRt')
%! assert (isempty(t))

%!test
%! [m, te, e, s, t] = regexpi('ShoRt Test String','\w*r\w*','once', 'match', 'tokenExtents', 'end', 'start', 'tokens');
%! assert (s,1)
%! assert (e,5)
%! assert (isempty(te))
%! assert (m,'ShoRt')
%! assert (isempty(t))

%!test
%! [s, e, te, m, t, nm] = regexpi('ShoRt Test String','(?<word1>\w*t)\s*(?<word2>\w*t)');
%! assert (s,1)
%! assert (e,10)
%! assert (size(te), [1,1])
%! assert (te{1}, [1 5; 7, 10])
%! assert (m{1},'ShoRt Test')
%! assert (size(t),[1,1])
%! assert (t{1}{1},'ShoRt')
%! assert (t{1}{2},'Test')
%! assert (size(nm), [1,1])
%! assert (!isempty(fieldnames(nm)))
%! assert (sort(fieldnames(nm)),{'word1';'word2'})
%! assert (nm.word1,'ShoRt')
%! assert (nm.word2,'Test')

%!test
%! [nm, m, te, e, s, t] = regexpi('ShoRt Test String','(?<word1>\w*t)\s*(?<word2>\w*t)', 'names', 'match', 'tokenExtents', 'end', 'start', 'tokens');
%! assert (s,1)
%! assert (e,10)
%! assert (size(te), [1,1])
%! assert (te{1}, [1 5; 7, 10])
%! assert (m{1},'ShoRt Test')
%! assert (size(t),[1,1])
%! assert (t{1}{1},'ShoRt')
%! assert (t{1}{2},'Test')
%! assert (size(nm), [1,1])
%! assert (!isempty(fieldnames(nm)))
%! assert (sort(fieldnames(nm)),{'word1';'word2'})
%! assert (nm.word1,'ShoRt')
%! assert (nm.word2,'Test')

%!assert(regexpi("abc\nabc",'.'),[1:7])
%!assert(regexpi("abc\nabc",'.','dotall'),[1:7])
%!test
%! assert(regexpi("abc\nabc",'(?s).'),[1:7])
%! assert(regexpi("abc\nabc",'.','dotexceptnewline'),[1,2,3,5,6,7])
%! assert(regexpi("abc\nabc",'(?-s).'),[1,2,3,5,6,7])

%!assert(regexpi("caseCaSe",'case'),[1,5])
%!assert(regexpi("caseCaSe",'case',"matchcase"),1)
%!assert(regexpi("caseCaSe",'case',"ignorecase"),[1,5])
%!test
%! assert(regexpi("caseCaSe",'(?-i)case'),1)
%! assert(regexpi("caseCaSe",'(?i)case'),[1,5])

%!assert (regexpi("abc\nabc",'C$'),7)
%!assert (regexpi("abc\nabc",'C$',"stringanchors"),7)
%!test
%! assert (regexpi("abc\nabc",'(?-m)C$'),7)
%! assert (regexpi("abc\nabc",'C$',"lineanchors"),[3,7])
%! assert (regexpi("abc\nabc",'(?m)C$'),[3,7])

%!assert (regexpi("this word",'S w'),4)
%!assert (regexpi("this word",'S w','literalspacing'),4)
%!test
%! assert (regexpi("this word",'(?-x)S w','literalspacing'),4)
%! assert (regexpi("this word",'S w','freespacing'),zeros(1,0))
%! assert (regexpi("this word",'(?x)S w'),zeros(1,0))

%!error regexpi('string', 'tri', 'BadArg');
%!error regexpi('string');

%!assert(regexpi({'asdfg-dfd';'-dfd-dfd-';'qasfdfdaq'},'-'),{6;[1,5,9];zeros(1,0)})
%!assert(regexpi({'asdfg-dfd','-dfd-dfd-','qasfdfdaq'},'-'),{6,[1,5,9],zeros(1,0)})
%!assert(regexpi({'asdfg-dfd';'-dfd-dfd-';'qasfdfdaq'},{'-';'f';'q'}),{6;[3,7];[1,9]})
%!assert(regexpi('Strings',{'t','s'}),{2,[1,7]})

*/


static octave_value
octregexprep (const octave_value_list &args, const std::string &who)
{
  octave_value retval;

  int nargin = args.length ();

  // Make sure we have string, pattern, replacement
  const std::string buffer = args(0).string_value ();
  if (error_state)
    return retval;

  const std::string pattern = args(1).string_value ();
  if (error_state)
    return retval;

  const std::string replacement = args(2).string_value ();
  if (error_state)
    return retval;

  // Pack options excluding 'tokenize' and various output
  // reordering strings into regexp arg list
  octave_value_list regexpargs (nargin-3, octave_value ());

  int len = 0;
  for (int i = 3; i < nargin; i++)
    {
      const std::string opt = args(i).string_value ();
      if (opt != "tokenize" && opt != "start" && opt != "end"
          && opt != "tokenextents" && opt != "match" && opt != "tokens"
          && opt != "names"  && opt != "split" && opt != "warnings")
        {
          regexpargs(len++) = args(i);
        }
    }
  regexpargs.resize (len);

  regexp::opts options;
  bool extra_args = false;
  parse_options (options, regexpargs, who, 0, extra_args);
  if (error_state)
    return retval;

  return regexp_replace (pattern, buffer, replacement, options, who);
}

DEFUN_DLD (regexprep, args, ,
  "-*- texinfo -*-\n\
@deftypefn  {Loadable Function} {@var{outstr} =} regexprep (@var{string}, @var{pat}, @var{repstr})\n\
@deftypefnx {Loadable Function} {@var{outstr} =} regexprep (@var{string}, @var{pat}, @var{repstr}, \"@var{opt1}\", @dots{})\n\
Replace occurrences of pattern @var{pat} in @var{string} with @var{repstr}.\n\
\n\
The pattern is a regular expression as documented for @code{regexp}.\n\
@xref{doc-regexp,,regexp}.\n\
\n\
The replacement string may contain @code{$i}, which substitutes\n\
for the ith set of parentheses in the match string.  For example,\n\
\n\
@example\n\
regexprep(\"Bill Dunn\",'(\\w+) (\\w+)','$2, $1')\n\
@end example\n\
\n\
@noindent\n\
returns \"Dunn, Bill\"\n\
\n\
Options in addition to those of @code{regexp} are\n\
\n\
@table @samp\n\
\n\
@item once\n\
Replace only the first occurrence of @var{pat} in the result.\n\
\n\
@item warnings\n\
This option is present for compatibility but is ignored.\n\
\n\
@end table\n\
@seealso{regexp, regexpi, strrep}\n\
@end deftypefn")
{
  octave_value_list retval;
  int nargin = args.length ();

  if (nargin < 3)
    {
      print_usage ();
      return retval;
    }

  if (args(0).is_cell () || args(1).is_cell () || args(2).is_cell ())
    {
      Cell str;
      Cell pat;
      Cell rep;
      dim_vector dv0;
      dim_vector dv1 (1, 1);

      if (args(0).is_cell ())
        str = args(0).cell_value ();
      else
        str = Cell (args(0));

      if (args(1).is_cell ())
        pat = args(1).cell_value ();
      else
        pat = Cell (args(1));

      if (args(2).is_cell ())
        rep = args(2).cell_value ();
      else
        rep = Cell (args(2));

      dv0 = str.dims ();
      if (pat.numel () != 1)
        {
          dv1 = pat.dims ();
          if (rep.numel () != 1 && dv1 != rep.dims ())
            error ("regexprep: inconsistent cell array dimensions");
        }
      else if (rep.numel () != 1)
        dv1 = rep.dims ();

      if (!error_state)
        {
          Cell ret (dv0);
          octave_value_list new_args = args;

          for (octave_idx_type i = 0; i < dv0.numel (); i++)
            {
              new_args(0) = str(i);
              if (pat.numel() == 1)
                new_args(1) = pat(0);
              if (rep.numel() == 1)
                new_args(2) = rep(0);

              for (octave_idx_type j = 0; j < dv1.numel (); j++)
                {
                  if (pat.numel () != 1)
                    new_args(1) = pat(j);
                  if (rep.numel () != 1)
                    new_args(2) = rep(j);
                  new_args(0) = octregexprep (new_args, "regexprep");

                  if (error_state)
                    break;
                }

              if (error_state)
                break;

              ret(i) = new_args(0);
            }

          if (!error_state)
            retval = args(0).is_cell ()
              ? octave_value (ret) : octave_value (ret(0));
        }
    }
  else
    retval = octregexprep (args, "regexprep");

  return retval;
}

/*
%!test  # Replace with empty
%! xml = '<!-- This is some XML --> <tag v="hello">some stuff<!-- sample tag--></tag>';
%! t = regexprep(xml,'<[!?][^>]*>','');
%! assert(t,' <tag v="hello">some stuff</tag>')

%!test  # Replace with non-empty
%! xml = '<!-- This is some XML --> <tag v="hello">some stuff<!-- sample tag--></tag>';
%! t = regexprep(xml,'<[!?][^>]*>','?');
%! assert(t,'? <tag v="hello">some stuff?</tag>')

%!test  # Check that 'tokenize' is ignored
%! xml = '<!-- This is some XML --> <tag v="hello">some stuff<!-- sample tag--></tag>';
%! t = regexprep(xml,'<[!?][^>]*>','','tokenize');
%! assert(t,' <tag v="hello">some stuff</tag>')

## Test capture replacement
%!test
%! data = "Bob Smith\nDavid Hollerith\nSam Jenkins";
%! result = "Smith, Bob\nHollerith, David\nJenkins, Sam";
%! t = regexprep(data,'(?m)^(\w+)\s+(\w+)$','$2, $1');
%! assert(t,result)

## Return the original if no match
%!assert(regexprep('hello','world','earth'),'hello')

## Test a general replacement
%!assert(regexprep("a[b]c{d}e-f=g", "[^A-Za-z0-9_]", "_"), "a_b_c_d_e_f_g");

## Make sure it works at the beginning and end
%!assert(regexprep("a[b]c{d}e-f=g", "a", "_"), "_[b]c{d}e-f=g");
%!assert(regexprep("a[b]c{d}e-f=g", "g", "_"), "a[b]c{d}e-f=_");

## Options
%!assert(regexprep("a[b]c{d}e-f=g", "[^A-Za-z0-9_]", "_", "once"), "a_b]c{d}e-f=g");
%!assert(regexprep("a[b]c{d}e-f=g", "[^A-Z0-9_]", "_", "ignorecase"), "a_b_c_d_e_f_g");

## Option combinations
%!assert(regexprep("a[b]c{d}e-f=g", "[^A-Z0-9_]", "_", "once", "ignorecase"), "a_b]c{d}e-f=g");

## End conditions on replacement
%!assert(regexprep("abc","(b)",".$1"),"a.bc");
%!assert(regexprep("abc","(b)","$1"),"abc");
%!assert(regexprep("abc","(b)","$1."),"ab.c");
%!assert(regexprep("abc","(b)","$1.."),"ab..c");

## Test cell array arguments
%!assert(regexprep("abc",{"b","a"},"?"),"??c")
%!assert(regexprep({"abc","cba"},"b","?"),{"a?c","c?a"})
%!assert(regexprep({"abc","cba"},{"b","a"},{"?","!"}),{"!?c","c?!"})

# Nasty lookbehind expression
%!test
%! assert(regexprep('x^(-1)+y(-1)+z(-1)=0','(?<=[a-z]+)\(\-[1-9]*\)','_minus1'),'x^(-1)+y_minus1+z_minus1=0')

*/