/* Tokenize UTF-8/UTF-16/UTF-32 string.
   Copyright (C) 1999, 2002, 2006, 2009-2022 Free Software Foundation, Inc.
   Written by Bruno Haible <bruno@clisp.org>, 2002.

   This file is free software.
   It is dual-licensed under "the GNU LGPLv3+ or the GNU GPLv2+".
   You can redistribute it and/or modify it under either
     - the terms of the GNU Lesser General Public License as published
       by the Free Software Foundation, either version 3, or (at your
       option) any later version, or
     - 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, or
     - the same dual license "the GNU LGPLv3+ or the GNU GPLv2+".

   This file 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
   Lesser General Public License and the GNU General Public License
   for more details.

   You should have received a copy of the GNU Lesser General Public
   License and of the GNU General Public License along with this
   program.  If not, see <https://www.gnu.org/licenses/>.  */

UNIT *
FUNC (UNIT *str, const UNIT *delim, UNIT **ptr)
{
  if (str == NULL)
    {
      str = *ptr;
      if (str == NULL)
        return NULL; /* reminder that end of token sequence has been reached */
    }

  /* Skip leading delimiters.  */
  str += U_STRSPN (str, delim);

  /* Found a token?  */
  if (*str == 0)
    {
      *ptr = NULL;
      return NULL;
    }

  /* Move past the token. */
  {
    UNIT *token_end = U_STRPBRK (str, delim);
    if (token_end)
      {
        *ptr = token_end + U_STRMBLEN (token_end);
        /* NUL-terminate the token.  */
        *token_end = 0;
      }
    else
      *ptr = NULL;
  }

  return str;
}