find

[Michael Burschik]

The guile ideas page lists an implementation of the find utility accepting
multiple procedures as a worthwile objective. But is it really?

As far as I understand the proposal, this would only be a shorthand for a
special case in which one wanted to apply several predicates and actions to
matching filenames, i.e.

(find directory (glob ".deps") directory? print-filename)

would be the same as

(find directory
  (lambda (filename)
    (and (glob ".deps" filename)
         (directory? filename)
         (print-filename filename))))

While the first version is certainly shorter, it is not necessarily clearer.

But things usually get more complicated. One frequently requires some kind
of comparison, such as

(< 30 (mtime filename))

or even a combination of various negated or combined predicates, such as

(and (not (owner "root" filename))
     (or (glob ".tmp" filename)
         (glob "*~" filename)
         (> (atime filename) 3)))

that are not so readily simplified, unless I am unable to see the simple
solution.

So what this would boil down to is a lot of syntactic sugar for the most
uninteresting special case the procedure might be used for. This isn't what
scheme is all about, or is it?

Regards

Michael Burschik