new module isblank

[Bruno Haible]

Here comes the 'isblank' module:

2009-10-18  Bruno Haible  <address@hidden>

        New module 'isblank'.
        * lib/isblank.c: New file.
        * m4/isblank.m4: New file.
        * modules/isblank: New file.
        * doc/posix-functions/isblank.texi: Mention the new module.

================================ lib/isblank.c ================================
/* Test whether a character is a blank.

   Copyright (C) 2009 Free Software Foundation, Inc.

   This program 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.

   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 General Public License for more details.

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

#include <config.h>

/* Specification.  */
#include <ctype.h>

int
isblank (int c)
{
  /* On all known platforms, in all predefined locales, isblank(c) is likely
     equivalent with  (c == ' ' || c == '\t').  Look at the glibc definition
     (in glibc/localedata/locales/i18n): The "blank" characters are '\t', ' ',
     U+1680, U+180E, U+2000..U+2006, U+2008..U+200A, U+205F, U+3000, and none
     except the first two is present in a common 8-bit encoding.  Therefore
     the substitute for other platforms is not more complicated than this.  */
  return (c == ' ' || c == '\t');
}
================================ m4/isblank.m4 ================================
# isblank.m4 serial 1
dnl Copyright (C) 2009 Free Software Foundation, Inc.
dnl This file is free software; the Free Software Foundation
dnl gives unlimited permission to copy and/or distribute it,
dnl with or without modifications, as long as this notice is preserved.

AC_DEFUN([gl_FUNC_ISBLANK],
[
  dnl Persuade glibc <ctype.h> to declare isblank().
  AC_REQUIRE([AC_USE_SYSTEM_EXTENSIONS])

  AC_REQUIRE([gl_CTYPE_H_DEFAULTS])
  AC_CHECK_FUNCS_ONCE([isblank])
  if test $ac_cv_func_isblank = no; then
    HAVE_ISBLANK=0
    CTYPE_H='ctype.h'
    AC_LIBOBJ([isblank])
  fi
])
=============================== modules/isblank ===============================
Description:
isblank() function: test whether a single-byte character is a blank.

Files:
lib/isblank.c
m4/isblank.m4

Depends-on:
extensions
ctype

configure.ac:
gl_FUNC_ISBLANK
gl_CTYPE_MODULE_INDICATOR([isblank])

Makefile.am:

Include:
<ctype.h>

License:
LGPLv2+

Maintainer:
Bruno Haible
===============================================================================
--- doc/posix-functions/isblank.texi.orig       2009-10-18 21:14:36.000000000 
+0200
+++ doc/posix-functions/isblank.texi    2009-10-07 11:12:33.000000000 +0200
@@ -4,15 +4,15 @@
 
 POSIX specification: 
@url{http://www.opengroup.org/onlinepubs/9699919799/functions/isblank.html}
 
-Gnulib module: ---
+Gnulib module: isblank
 
 Portability problems fixed by Gnulib:
 @itemize
address@hidden
+This function is missing on some platforms:
+AIX 4.3.2, IRIX 6.5, OSF/1 5.1, Solaris 9, mingw.
 @end itemize
 
 Portability problems not fixed by Gnulib:
 @itemize
address@hidden
-This function is missing on some platforms:
-AIX 4.3.2, IRIX 6.5, OSF/1 5.1, Solaris 9, mingw.
 @end itemize