Re^2: Perl OO: switch package context.

OK, that works indeed. But (oh, I know it is cruel) I need to do that at runtime, within eval context.

So:

use aliased Foo::Bar::Object;
print ref Object->new();
[download]

works, so works this one:

use constant Object => 'Foo::Bar::Object';
print ref Object->new();
[download]

But eval'ing this stuff does not:

eval 'use aliased Gemini::Model::Object;';
print ref Object->new();
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or:

eval qq[use constant Object => 'Foo::Bar::Object';];
print ref Object->new();
[download]

What's wrong with that? :)

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Re^3: Perl OO: switch package context. by bart (Canon) on May 15, 2005 at 20:45 UTC
It's too late at runtime, the rest of the script already got compiled. So "Object" is taken as a bareword string literal, and nothing can change that. As a `constant` is nothing but a sub, you can use a similar sub that just returns the value of a scalar. You can always change the value for the scalar. `my $class = "Gemini::Model::Object"; sub Object () { return $class; } print ref Object->new();` [download] You can always still change the value of that scalar. But why the obfuscation? If you want to use a variable class, just say so. Perl lets you do that. `my $class = "Gemini::Model::Object"; print ref $class->new();` [download] Looks fine to me.	[reply] [d/l] [select]

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Re^3: Perl OO: switch package context.
by bart (Canon) on May 15, 2005 at 20:45 UTC

As a constant is nothing but a sub, you can use a similar sub that just returns the value of a scalar. You can always change the value for the scalar.

my $class = "Gemini::Model::Object";
sub Object () {
    return $class;
}
print ref Object->new();
[download]

But why the obfuscation? If you want to use a variable class, just say so. Perl lets you do that.

my $class = "Gemini::Model::Object";

print ref $class->new();
[download]

[reply]
[d/l]
[select]