On Thu, Jul 9, 2009 at 6:22 PM, Moritz Lenz <mor...@faui2k3.org> wrote:

> $str.File.e             # same, different names

Brainstorming a bit here....

Str is a class that describes collections of characters (among some other
typographical constructs, yadda, yadda, Unicode, yadda).

There is a commonly used special case, however, where my Str is not just a
Str. It is, instead, a key for an external datasource. Such cases include:

* URIs.
* Pathnames
* Usernames
* Variable names
* etc.

It makes sense to handle these cases in some regular way, and to provide
those hooks via Str because it is relatively uniquely Str's job to hold
these things (counter-examples include UIDs).

OK, so we have a need for some hookable interface on Str for accessing
external datasources by key. Let's call it "key".

$str = "/etc/aliases"
$str.e; # error, no such method
$str.e; # works fine

There should probably be a few standard methods that are imported in this
way such as e, s, z and any other test operators that are universal, so that
this makes sense:

 $user = get_user_name();
 $user.e; # user exists?

 $url = "http://www.example.com/";;
 $url.s > 0; # might do a HEAD request and return the size

The rest might be more domain specific:

 $mailbox = "Trash";
 $mailbox.key(::Mail::IMAP, $account_info);
 $mailbox.msgs > 1000;

In this way you have not enforced the assumption that all strings are
pathnames, but rather that all strings might be used as keys.

I suppose this even makes sense, though it's convoluted:

 $hashkey = "Aaron";
 $hashkey.key(::Hash, %names);

The real beauty of this is that it can all be implemented without any
language syntax/grammar changes.

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