Re: Q: something like autoload for coding-systems?

[Richard Stallman]

    No, I mean by "mapping table" a more general concept, a
    table that contains a mapping information between a
    code-point of some charset and the correponding character
    code.

That is what I thought it meant.

Isn't it possible for find-coding-system-region to work with a much
smaller amount of information?  For instance, it could use a list of
intervals (in the mathematical sense), saying that coding system FOO
handles character codes X through Y and A through B and C through D.
This would be far less information than the mapping table.