Re: Dynamic loading progress

[Paul Eggert]

Aurélien Aptel wrote:
> I've replaced
> DEFSYM calls with:
>
>      MQfoo = intern ("foo")
>
> Are there any drawbacks?

It's a bit slower.  Symbols like Qabove are compile-time constants; on my 
platform, for example, Qabove == 8688, and this integer is known at 
compile-time.  This gives C compilers more opportunities for optimization than 
variables like MQfoo do.

> The fact that
> globals are actually macros exanding to a global struct member is not
> desirable here as it prevents normal C lexical scoping.

That sounds like it might be more trouble than it's worth.  These symbols are 
globally unique anyway, in Elisp, so it's a bit clearer to keep them globally 
unique in C as well, rather than attempt to reuse them with C lexical scoping.