Re: RFC 218 (v1) C<my Dog $spot> is just an assertion

Perl6 RFC Librarian <[email protected]> writes:

> This and other RFCs are available on the web at
>   http://dev.perl.org/rfc/
> 
> =head1 TITLE
> 
> C<my Dog $spot> is just an assertion
> 
> =head1 VERSION
> 
>   Maintainer: Piers Cawley <[email protected]>
>   Date: 13th September 2000
>   Mailing List: [email protected]
>   Number: 218
>   Version: 1
>   Status: Developing
> 
> =head1 ABSTRACT
> 
> The behaviour of the <my Dog $spot> syntax should simply be an
> assertion of the invariant: 
> 
>    (!defined($spot) || (ref($spot) && $spot->isa('Dog)))
> 
> =head1 DESCRIPTION
> 
> The syntax 
> 
>     my Dog $spot = Dog->new();
> 
> currently carries little weight with Perl, often failing to do what
> one expects:
> 
>     $ perl -wle 'my Dog::$spot; print "ok"' 
>     No such class Dog at -e line 1, near "my Dog"
>     Execution of -e aborted due to compilation errors.
>     $ perl -wle 'sub Dog::new; my Dog $spot; print "ok"'
>     ok
>     $ perl -wle 'sub Dog::new; my Dog $spot = 1'
>     ok
> 
> The first example is obvious, as is the second. The third one is
> I<weird>.  

Actually, it's *very* weird given that there's no code to print 'ok'.
Which is bad.

      $ perl -wle 'sub Dog::new; my Dog $spot = 1; print "ok"'

That's better.

-- 
Piers