It'd be difficult to get exactly the same syntax without a filter. A subroutine named class with a prototype of (@&) could get you part way there. It could be called like class 'Foo' extends => qw( Bar Baz ) { . . . };.

Instead of using the builtin sub definition, you could create a new subroutine named method with a prototype of ($@&) which could be called as method method_name => ('$attr1', '@attr2', '%attr3') { . . . };. This would then generate the regular Perl subroutine.

I probably got the prototypes wrong, as I don't usually have a use for them.

Alternatively, you can do what everybody else is doing: wait for Perl6 :)