Larry Wall <[EMAIL PROTECTED]> wrote: > $x is visible only in the rest of the lexical scope. In contrast, > $_y would presumably still be visible if the class were reopened.
This strikes me as an exceedingly bad idea. Encapsulation is a very good thing, and I'm glad it's being added to Perl 6. But once in a while, you really *do* need to break encapsulation. Maybe a shortsighted module author didn't add an accessor you need, or maybe you're doing something highly magical for (e.g.) debugging. In any case, though, you'll need an escape hatch, and I really think extending a class should be it. By extending a class, you're explicitly saying "I'm going to butt into your affairs"; at this point, if you're not sure what you're doing, you're probably going to mess things up *anyway*. (If not this, I at least would like to see a way to make roles and/or class extensions optionally merge their namespace with the class they're being composed into; a simple 'is merged' on the role/extension's definition might do.) Also note how subtle this point is (it's about the only point I didn't get from the original message); the degree to which it requires the class's programmer to predict how others might want to extend his class; and the syntactic kludge required to specify it (namely, the sometimes-magical underscore). I really think this is a very fine distinction, which programmers will get wrong half the time, and which you don't even have enough syntax to cope with *anyway*. -- Brent 'Dax' Royal-Gordon <[EMAIL PROTECTED]> Perl and Parrot hacker
