Re: Emacs rewrite in a maintainable language

[Oleh Krehel]

Óscar Fuentes <address@hidden> writes:

> Replacing C with a language that helps people to write readable, safe,
> efficient and maintainable code without having to study the existing
> code base for months looks quite appealing to me. That replacement could
> be gradual (no "stopping the world while The Big Rewrite is underway.")
> If that language is not so popular as C, that's no big problem as long
> as it makes things less daunting for those willing to work on the Emacs
> core. As already said, there is no dramatic shortage of people who learn
> Elisp just for hacking Emacs.

I think slowly moving the Emacs C core to C++ is a good idea.  The two
languages are supposed to be largely compile-compatible, i.e. g++ can
understand what was meant for gcc.

I've been trying to get into understanding Emacs C core, but it's just
so hard with all those macros around. I think even replacing `#define`
with `const` would be a huge improvement, worthwhile of the switch.  The
second step would be to replace some macros with type checked template
functions. Finally, write proper classes for buffer/window/frame/font
etc. Nothing too complex like virtual functions, operator overloading or
hardcore template meta-programming that puts people off C++, just basic
encapsulation to see which code uses what and the type of data being
operated on.

I don't have sufficient C/C++ experience to initiate this change.  But
if someone were to lead, I'd help as much as I could.

If other people and the new maintainer were to support the C -> C++
move, the change could be very gradual, with a lot of functions not
changing at all. In an ideal world, the change would be initiated by
e.g. deciding to use C++11 and swapping `cc` for `g++` in the Makefiles,
without changing the code at all. Of course it's never as simple as
that.

    Oleh