Re: [Chicken-hackers] [PATCH] handle EOVERFLOW and ENOTDIR gracefully in file/directory-exists?

[Alan Post]

On Sat, Oct 08, 2011 at 04:11:47PM -0400, John Cowan wrote:
> Christian Kellermann scripsit:
> 
> > Wouldn't the right answer be in this case "We don't know whether this
> > file exists, because some Bad Thing(tm) happened while trying to find
> > out" instead of yes or no?
> 
> No.  If ENAMETOOLONG is returned, the file can't possibly exist (because
> the filesystem has no way to represent it), so it's always correct to
> return #f in that case.
> 
> > Depending on my use case I might be screwed either way if file-exists?
> > returns a valid answer.
> 
> Only in the sense that if it returns #f you may then try to create it,
> which will fail with another ENAMETOOLONG (which in this case should raise
> a Scheme exception).  So you have to be prepared for create to fail even
> if file-exists? returns #f (as in many other cases: permissions, e.g.)
> 

Thank you John, that is a better articulation of why one would
handle ENAMETOOLONG than I gave.

-Alan
-- 
.i ma'a lo bradi cu penmi gi'e du