Re: Using custom as a type checker:- ramble

["Stefan Monnier" <monnier+gnu.emacs.help/news/@flint.cs.yale.edu>]

Stefan> It should be possible to get the desired result without
Stefan> implementing an elisp interpreter in elisp, but instead by
Stefan> temporarily rebinding `setq' as a macro (and things like
Stefan> that).
> I think that would be fairly hard! setq is such a basic function, and
> to change it so that it worked correctly, but still failed at the
> appropriate time. 

I don't intend it to fail any more than the plain `setq' does.
The only difference would be a bunch of warnings.

> I presume you are still suggesting using the type information in
> custom to make the determination as to whether an .emacs setq was
> "type safe" or not? If this is the case, it would seem the two
> approaches (a custom-setq, or augmented setq) would use a lot of
> common code.

Probably, but without making it visible at the source level and
without impacting the semantics of the code at all.


        Stefan