Since there were no more comments on my previous reply I will pick the
option I like best :) The performance is anyway very good regardless
which option I take.

Now for another matter: documentation. I've been thinking about where to
best describe this new feature. It does not need a very length
description I think, but we should mention it in the manual. Here is the
current "menu" for Abbrevs:

* Abbrev Concepts Fundamentals of defined abbrevs.
* Defining Abbrevs Defining an abbrev, so it will expand when typed.
* Expanding Abbrevs Controlling expansion: prefixes, canceling expansion.
* Editing Abbrevs Viewing or editing the entire list of defined abbrevs.
* Saving Abbrevs Saving the entire list of abbrevs for another session.
* Dynamic Abbrevs Abbreviations for words already in the buffer.
* Dabbrev Customization What is a word, for dynamic abbrevs. Case handling.

Any thoughts on this?

Also, once the documentation is done, what would be the steps, in git,
to get this into Emacs? Are we using feature branches? Do people commit
to master? Or can I send a patch by e-mail? (less risk of me messing
up...)

Thanks!