Re: Trouble using (current-filename)

[Andy Wingo <wingo@pobox.com>]

Hi,

On Sun 19 Feb 2012 15:10, ludo@gnu.org (Ludovic Courtès) writes:

> Andy Wingo <wingo@pobox.com> skribis:
>
>> On Fri 17 Feb 2012 23:49, ludo@gnu.org (Ludovic Courtès) writes:
>>
>>> Would it work to let the user call it themself if needed, like:
>>>
>>>   (add-to-load-path (dirname (canonicalize-path (current-filename))))
>>
>> I would rather have current-filename do a
>>
>>   (or (false-if-exception (canonicalize-path p)) p)
>>
>> Current-filename sounds like it should do the right thing, if possible.
>
> I think it’s often undesirable.
>
> Suppose you want to use ‘current-filename’ in an ‘assert’ macro, for
> instance: what you want is a hint, not an absolute path, since that path
> is likely to be invalid at the time you see it (for instance, it could
> point to the source tree on a build machine of your distro.)
>
> Furthermore, including absolute paths by default makes builds
> non-deterministic: two users would get different binaries, just because
> they built things under a different directory.
>
> Thus, I’d rather let users call ‘canonicalize-path’ when they know what
> they’re doing, and know that they actually need it.
>
> WDYT?

I'm fine with that, but I think you are concerned more about code in
modules (compiled in one location, installed and run from another) than
for local scripts.

See Neil's use case here:

  http://thread.gmane.org/gmane.lisp.guile.devel/13440/focus=13621

Can we do something that makes sense for both cases?  For example, we
might canonicalize-path only if we don't find the filename within the
current load path.

Andy
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