Re: find for guile

[Jorgen 'forcer' Schaefer]

Marco Maggesi <address@hidden> writes:

> I started to write a `find' procedure for guile. 

Great!

> I wonder if it would be more appropriate to implement the
> function `glob' in C or in Scheme.  Any suggestion?

There's fnmatch(3) and glob(3), both conforming to POSIX.2, maybe
you want to check them (or at least the glibc implementation)
out.

Glob in C would be faster, and since you could use fnmatch if
it's provided, easier to implement.

> I also would like to propose an extension to accept lists
> (to mean `or' instead of `and') as argument to `find' as in
> the following example:

I don't think this is a good idea, it confuses more than it
cleans up, IMHO.

>   (find "."
>         regular?    ; skip links and directory
>         '("*~" "*.BAK" empty?)
>         delete-file)

(find "."
      regular?
      (or "*~" "*.BAK" empty?)
      delete-file)

would be much "cleaner" in my opinion.  Also, this can be used
for nesting much cleaner:

(find "."
      regular?
      (or (and "*~" (not orig-exists?))
          empty?)
      delete-file)

(orig-exists? would check wether the original file exists (file
without ~), so this whole thing would delete empty files or
backup files for which there's no original file.)

This way, the arguments to find meaning "and" is a special
exception.

By the way, so that the arguments to find can mean "and", you
have to make find a special form anyways (using define-syntax),
so you can scratch the quote there :)

Also, it would be nice if there'd be a way that find would return
a list of results ...

I'm pretty green too, so don't take my words as The Right Thing.
I'm sure others will comment as well.
        -- jorgen

-- 
((email . "address@hidden")       (www . "http://forcix.cx/";)
 (irc   . "address@hidden (IRCnet)") (gpg .    "1024D/028AF63C"))