Re: Introducing `cond-feature'

[Kevin Ryde]

address@hidden (Ludovic Courtès) writes:
>
> Quoting SRFI-0:
>
>   Another issue is the binding time of this construct (i.e. the moment
>   when it operates). It is important that the binding time be early so
>   that a compiler can discard the sections of code that are not needed,
>   and perform better static analyses. Expressing this construct through
>   a procedure returning a boolean, such as (feature-implemented?
>   'srfi-5), would not achieve this goal, as its binding time is too late
>   (i.e. program run-time).

I wouldn't take that as the last word on compiling.  I think you
should wait until a guile compiler exists before worrying how to help
it! :)  (Ie. leave cond-feature out for the moment.)

One thing to consider is that the features now are basically build
options or system features of the runtime, so hypothetical compiled
code is quite likely to want to adapt at runtime too.  Perhaps when
there's two compiled guiles it'll be of interest how to distinguish
them at compile-time.