/* Expression parsing for plural form selection.

   Copyright (C) 2000-2026 Free Software Foundation, Inc.

   This program 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.

   This program 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 this program.  If not, see <https://www.gnu.org/licenses/>.  */

/* Written by Ulrich Drepper and Bruno Haible.  */

#ifdef HAVE_CONFIG_H

# include <config.h>

#endif

#include <ctype.h>

#include <stdlib.h>

#include <string.h>

#include <plural-exp.h>

/* These structs are the constant expression for the germanic plural

   form determination.  It represents the expression  "n != 1".  */

static const struct expression plvar =

{

  .nargs = 0,

  .operation = var,

};

static const struct expression plone =

{

  .nargs = 0,

  .operation = num,

  .val =

  {

    .num = 1

  }

};

const struct expression GERMANIC_PLURAL =

{

  .nargs = 2,

  .operation = not_equal,

  .val =

  {

    .args =

    {

      [0] = (struct expression *) &plvar,

      [1] = (struct expression *) &plone

    }

  }

};

void

EXTRACT_PLURAL_EXPRESSION (const char *nullentry,

         const struct expression **pluralp,

         unsigned long int *npluralsp)

{

  if (nullentry != NULL)

    {

      const char *plural = strstr (nullentry, "plural=");

      const char *nplurals = strstr (nullentry, "nplurals=");

      if (plural == NULL || nplurals == NULL)

  goto no_plural;

      else

  {

    /* First get the number.  */

    nplurals += 9;

    while (*nplurals != '\0' && isspace ((unsigned char) *nplurals))

      ++nplurals;

    if (!(*nplurals >= '0' && *nplurals <= '9'))

      goto no_plural;

    char *endp;

    unsigned long int n = strtoul (nplurals, &endp, 10);

    if (nplurals == endp)

      goto no_plural;

    *npluralsp = n;

    /* Due to the restrictions bison imposes onto the interface of the

       scanner function we have to put the input string and the result

       passed up from the parser into the same structure which address

       is passed down to the parser.  */

    plural += 7;

    struct parse_args args;

    args.cp = plural;

    if (PLURAL_PARSE (&args) != 0)

      goto no_plural;

    *pluralp = args.res;

  }

    }

  else

    {

      /* By default we are using the Germanic form: singular form only

         for `one', the plural form otherwise.  Yes, this is also what

         English is using since English is a Germanic language.  */

    no_plural:

      *pluralp = &GERMANIC_PLURAL;

      *npluralsp = 2;

    }

}