/* Simple strspn.

   Copyright (C) 2022 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library 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 for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <https://www.gnu.org/licenses/>.  */

#include <string.h>

size_t strspn (const char *str, const char *accept)
{
  if (accept[0] == 0)
    return 0;
  if (accept[1] == 0)
    {
      const char *p;
      for (p = str; *p == accept[0]; p++);
      return p - str;
    }

  unsigned char table[256] = {0};
  unsigned char *us;
  for (us = (unsigned char*) accept; *us != 0; table[*us++] = 1);

  for (us = (unsigned char*) str; table[*us] != 0; us++);
  return us - (unsigned char *) str;
}
libc_hidden_builtin_def (strspn)