Re: PATCH to add euro symbol to French-{postfix, alt-postfix, prefix} input methods

[Richard Stallman <rms@gnu.org>]

    It is not related to input methods.  In fact, I find it somewhat silly
    to have different latin-x input methods at all.  Why don't we replace
    them all with a single latin-x input method, or with language specific
    ones?

We should try to write general latin-everything input methods, but
since they will have lots of combinations to make for each letter,
they may be quite inconvenient to USE.  There may be too many active
prefixes or suffixes, and they can get in the way of ordinary typing.

Making the general latin-everything as convenient as is feasible
be could be a difficult job of tuning.

Until we see that people prefer these general methods to the
individual Latin-N input methods, we should not even think of deleting
those.

      It would make more sense to have some mechanism complain
    upon any way of inserting non-encodable characters (using buffer
    modification hooks, for example), and then have just one generic
    well-maintained latin input method rather than a dozen "forks".

Trying to save with characters that cannot be encoded will already
warn you.  I am not sure it is useful to detect those characters when
they are inserted, but if it is, there are various ways to do that.
Maybe we could make Font Lock highlight them.