@setfilename standards.info
@settitle GNU Coding Standards
@c This date is automagically updated when you save this file:
-@set lastupdate April 27, 2013
+@set lastupdate September 13, 2013
@c %**end of header
@dircategory GNU organization
@cindex programming languages
When you want to use a language that gets compiled and runs at high
-speed, the best language to use is C. Using another language is like
-using a non-standard feature: it will cause trouble for users. Even if
-GCC supports the other language, users may find it inconvenient to have
-to install the compiler for that other language in order to build your
-program. For example, if you write your program in C++, people will
-have to install the GNU C++ compiler in order to compile your program.
-
-C has one other advantage over C++ and other compiled languages: more
-people know C, so more people will find it easy to read and modify the
-program if it is written in C.
-
-So in general it is much better to use C, rather than the
-comparable alternatives.
-
-But there are two exceptions to that conclusion:
-
-@itemize @bullet
-@item
-It is no problem to use another language to write a tool specifically
-intended for use with that language. That is because the only people
-who want to build the tool will be those who have installed the other
-language anyway.
-
-@item
-If an application is of interest only to a narrow part of the community,
-then the question of which language it is written in has less effect on
-other people, so you may as well please yourself.
-@end itemize
+speed, the best language to use is C. C++ is ok too, but please don't
+make heavy use of templates. So is Java, if you compile it.
+
+When highest efficiency is not required, other languages commonly used
+in the free software community, such as Scheme, Python, Ruby, and
+Java, are OK too. Scheme, as implemented by GNU@tie{}Guile, plays a
+particular role in the GNU System: it is the preferred language to
+extend programs written in C/C++, and also a fine language for a wide
+range of applications. The more GNU components use Guile and Scheme,
+the more users are able to extend and combine them (@pxref{The Emacs
+Thesis,,, guile, GNU Guile Reference Manual}).
Many programs are designed to be extensible: they include an interpreter
for a language that is higher level than C. Often much of the program
Guile also includes bindings for GTK+/GNOME, making it practical to
write modern GUI functionality within Guile. We don't reject programs
written in other ``scripting languages'' such as Perl and Python, but
-using Guile is very important for the overall consistency of the GNU
-system.
+using Guile is the path that will lead to overall consistency of the
+GNU system.
@node Compatibility
@section Mmap
@findex mmap
-Don't assume that @code{mmap} either works on all files or fails
-for all files. It may work on some files and fail on others.
+If you use @code{mmap} to read or write files, don't assume it either
+works on all files or fails for all files. It may work on some files
+and fail on others.
The proper way to use @code{mmap} is to try it on the specific file for
which you want to use it---and if @code{mmap} doesn't work, fall back on
@example
--prefix --exec-prefix --bindir --sbindir --libexecdir --sysconfdir
---sharedstatedir --localstatedir --libdir --includedir --oldincludedir
+--sharedstatedir --localstatedir --runstatedir
+--libdir --includedir --oldincludedir
--datarootdir --datadir --infodir --localedir --mandir --docdir
--htmldir --dvidir --pdfdir --psdir
@end example