2017-12-10 16:26 GMT+01:00 David T. Lewis <lewis at mail.msen.com>:

> On Sun, Dec 10, 2017 at 11:09:04AM +0100, Nicolas Cellier wrote:
> > 2017-12-10 9:53 GMT+01:00 Marcel Taeumel <marcel.taeumel at hpi.de>:
> >
> > > So it comes down to what "being abstract" actually means in the
> > > environment. :-) I think it means #== considering the current VM and
> the
> > > role of classes. Not sure in a the generic, object-oriented sense,
> though.
> > >
> > > Best,
> > > Marcel
> > >
> > > Am 10.12.2017 00:02:06 schrieb Chris Muller <asqueaker at gmail.com>:
> > > With objects you should delegate to the the receiver to decide what #=
> > > means -- which in most cases will inherit that default implementation
> from
> > > Object anyway.  Sending #== is generally bad form.
> > >
> > > Converting uses of #= to #== for "performance" is a bad idea except in
> the
> > > most inner, performance-critical code, and even then, it should be
> with a
> > > comment.
> > >
> > > Absolutely, if it's only for the sake of optimization, it's a bad
> decision.
> > Not to mention that isAbstract is not performance critical at all.
> >
> > Maybe the intention is to really test for identity.
> > That's because we have the knowledge that classes are the unique instance
> > of their metaclass.
> > So using = could be seen as an un-necessary indirection.
> >
> > Reducing the level of indirection may reduce complexity.
> > But it is also reducing extensibility as noted by Marcel.
> >
> > But do we want to elimiate complexity at all?
> > I see this related to "complex versus complicated" and the original
> > biological analogy.
> > Are resilient/adptative systems necessarily complex?
> > If so, ideally such complex system should be built from simple
> > behavior/rules.
> > What we want to avoid if possible is complicated things.
>
> Is one of these two approaches less complicated and easier to understand
> with respect to Environments? I don't know the answer, just asking.
>
> Dave
>
>
> Hi David,
I don't think so.
Different environments may have different bindings, but those point on same
class.
== suppress one level of indirection with implicit knowledge that classes
are unique.
IMO = does not make things more complicated.
But such indirection might be useful only if one day someone start using
copies of a class and give a new definition of =
That's hypothetical for now.

>
> > Nicolas
> >
> > >
> > > On Thu, Dec 7, 2017 at 2:30 AM, Marcel Taeumel <marcel.taeumel at hpi.de>
> > > wrote:
> > >
> > >> Hi, there.
> > >>
> > >> What are your thoughts on how to implement "MyClass class >>
> > >> #isAbstract"? I think that one should always use #== and compare it
> to an
> > >> actual class object like this:
> > >>
> > >> MyClass class >> #isAbstract
> > >>    ^ self == MyClass
> > >>
> > >> At the time of writing, we have various attempts in your image. You
> can
> > >> browse them easily:
> > >>
> > >>
> > >> Best,
> > >> Marcel
> > >>
> > >>
> > >>
> > >>
> > >
> > >
> > >
> > >
>
> >
>
>
>
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