On 13 Oct 2009, at 12:03 am, John Cowan wrote:

> Alaric Snell-Pym scripsit:
>
>> How do you handle conditional imports based on availability of
>> modules?
>>
>> Eg, "if we have opengl libraries, use them, otherwise do our own slow
>> software rendering".
>
> I think that is best handled by conditional inclusion rather than
> conditional import.  You write a single module which exports a fixed
> interface and then, depending on a con-expand in the body, includes
> either
> the open-gl glue code or the software emulation code.  This relies on
> people having the self-discipline to adopt the Scheme48 style of
> module,
> where the body normally consists only of includes.

So you're allowed to put the imports inside cond-expand if they're in
a separate file that gets included, and not otherwise?

I'm confused. Sure, using includes like that is a nice way to make
your code more manageable, but why should it have any effect on how
you conditionalise module metadata?

ABS

--
Alaric Snell-Pym
Work: http://www.snell-systems.co.uk/
Play: http://www.snell-pym.org.uk/alaric/
Blog: http://www.snell-pym.org.uk/archives/author/alaric/




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