"Drieux" <[EMAIL PROTECTED]> wrote in message
news:[EMAIL PROTECTED]
>
> On Friday, Sep 12, 2003, at 18:54 US/Pacific, Todd W. wrote:
> [..]
> > I dont think you can call that a closure yet. You would have to be
> > defining
> > subroutines that refer to lexical variables outside of the subroutine
> > or
> > something along those lines:
> >
> > [EMAIL PROTECTED] trwww]$ perl
> > {
> > my $dog = 'spot';
> > sub dogsName {
> > my $pooch = $dog;
> > return("my dog is $pooch");
> > }
> > }
> [..]
>
> Mea Kulpa! What Was I Thinking? I just did the
>
> perldoc -q closure
>
> but..... hum...
>
> {
> package Foo::Bar
> use base qw/Foo/;
> ...
> }
>
> Would seem to meet the minimum requirement, since
> the 'use base' there deals with the @ISA for that
> package name space...
>
The block is still not a closure, because @ISA must be a package global for
the inhertance mechanism to work its magic.
use base qw/Foo/;
is semantically the same as:
our(@ISA) = qw/Foo/;
As a matter of fact, declaring @ISA as a lexical will effectively disable
inheritance for a given module:
[EMAIL PROTECTED] trwww]$ perl
use warnings;
use strict;
use CGI;
{
package Foo;
our(@ISA) = qw/CGI/;
}
# inerited class method
print Foo->escapeHTML('foo&bar'), "\n";
Ctrl-D
foo&bar
and then:
[EMAIL PROTECTED] trwww]$ perl
use warnings;
use strict;
use CGI;
{
package Foo;
my(@ISA) = qw/CGI/;
}
print Foo->escapeHTML('foo&bar'), "\n";
Ctrl-D
Can't locate object method "escapeHTML" via package "Foo" at - line 10.
Beacuse of @ISA being lexically declared, it can't inherit from other
modules. And remember, for a logical scope to be called a closure, you have
to be dealing with lexical values.
> But I think the part that scares me is that
>
> my $action = {
> doDaemon => sub { ..... },
> ...
> };
>
> would get us into the same 'space'?
Not if you declare $action to have its own file or block scope. You would
have to define an accessor to access $action.
>
> I'm not sure I really want to actually create YA_CGI_AppServer,
> although, I fear that I am in dire meandering towards that sort
> of 'can one create a general enough solution'....
>
> Since, well, uh, one of my doodles is about passing in a
> reference to an object, and such things ... Since the basic
> 'shell' of a CGI script still looks like:
<snip CGI parser example />
> make_header_and_send($page_type, $page);
>
> so that of course yearns to be in a module, rather than
> as something one would cut and paste into each new CGI script...
>
> But looking at your diagramme, I think I can see why you
> are pointing towards a YA_CGI_AppServer....
>
If you have a reuseable component that dispatches other components you can
call it an application server, for some definitions of an application
server.
Todd W.
--
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
