From: Robert Klemme <bob.news@...>
Date: 2004-09-29T18:19:19+09:00
Subject: Re: Best name for "this method" ?


"trans. (T. Onoma)" <transami@runbox.com> schrieb im Newsbeitrag
news:200409281953.36428.transami@runbox.com...
> On Tuesday 28 September 2004 06:31 pm, David A. Black wrote:
> > > Right. Well then, I must propose that all such class names be
constructor
> > > methods too. No sense in confusing things otherwise. By default:
> > >
> > >   def AClass(*args, &blk)
> > >     AClass.new(*args, &blk)
> > >   end
> >
> > I'm not getting the point of that.  Why do you need a wrapper like
> > that around new?  Also, the one somewhat common case of this --
> > Integer -- isn't a wrapper for new, since there is no Integer.new.  So
> > you'd be introducing a constraint that currently doesn't exist.
>
> Sorry, I should explain better. Let me put it this way: Why would I want
to
> write a constructor like Hash[], when it could just as well be written
> Hash()? And in fact I don't --I cannot think of a single time that I
have
> used the later notation. Why? *Not* because it isn't useful, but rather
b/c
> it obfuscates my code b/c is looks like an Array or Hash lookup, and not
like
> calling a constructor method.
>
> > > But for something like Hash, it would be defined like Hash[].
> >
> > What is "something like Hash" in this context?  I'm not following
> > here.
>
> In other words, I am not saying it has to be X() == X.new(). Rather
Hash() can
> do what Hash[] does. And likewise for Integer(). They are specialized
> constructor methods.
>
> So my point, really, is simply, why not have this be default behavior
for all
> classes? Specialized forms can be specially defined, the others can be
> equivalent to #new. Personally I like the look of it too.

I prefer #new because it emphasizes the factoryness of a Class instance.
Class() doesn't help you in cases like these:

class SomeFactory
  def initialize(cl)
    @cl = cl
  end

  def create() @cl.new end
  def discard(obj) end
end

Also, methods Integer() and such are defined in Kernel.  Having such a
method as a wrapper for C.new in Kernel for every class would clutter
Kernel unnecessarily and introduce unnecessary dependencies.  I try to
stick to the rule of thumb to change base classes as minimal as possible.
That way code stays maintainable and the likeliness of imcompatibilities
between different classes that change Kernel and the like decreases.

Kind regards

    robert