Front page | perl.perl5.porters |
Postings from May 2004
Gisle Aas <gisle@ActiveState.com>:
> Mark Jason Dominus <mjd@plover.com> writes:
>
> > hv@crypt.org:
> > > Gisle Aas <gisle@ActiveState.com> wrote:
> > > :Another option is simply to pass a closure that capture the arguments
> > > :you want your callback to receive.
> > > :But again, I think File::Find is fine as it is.
> > >
> > > I agree,
> >
> >
> > It's not always convenient to do that.
>
> The sub{} wrapper will seldom be much more typing than providing args
> any another way, so I don't find it very inconvenient either.
I didn't say anything about the quantity of typing, and I don't think
the amount of typing saved or not saved is important.
I said that it isn't always convenient to define the callback function
in the same scope as the call to File::Find::find.
For example, it is not convenient to have a module which provides
callback functions to be used with File::Find.
Suppose for example one is trying to locate all the dangling symbolic
links under a directory. One might write
use File::Find;
{ my @dangles;
my $dangling_symlinks =
sub { push @dangles, $File::Find::name if -l && ! -e };
find({wanted => $dangling_symlinks}, $TOP);
# Now do something with @dangles
}
and this is no problem. But suppose the 'dangling_symlinks' function
was provided by a module, so one would write:
use File::Find;
use File::Find::Common 'dangling_symlinks';
my @dangles;
find({wanted => \&dangling_symlinks}, $TOP);
# Now do something with @dangles
No, this doesn't work, and it can't be made to work, because
File::Find::Common::dangling_symlinks is not in the scope of my
@dangles.
Normally one would simply pass an argument to
File::Find::Common::dangling_symlinks with a reference to the target
array. But the File::Find API does not support this. The proposal is
simply to support it.
Thread Previous
|
Thread Next