Re: [ANN] MacRuby

On 2/28/08, Eero Saynatkari <[e-mail]> wrote:
> On 2008.02.29 08:15, Yukihiro Matsumoto wrote:
>  > That is very important design decision.  Objective-C-ish calling or
>  > Ruby-ish calling.  The latter makes program consistent, but the former
>  > makes program obvious. Hmm.
>
>
> Actually, this would be a really great time to talk about trying to unify
>  the keyword argument syntax across implementations so that we do not have
>  to have that discussion later or contend with several variants. I know that
>  we are not at the 2.0 threshold yet, but obviously folks are starting to
>  get there.
>
>  In the particular case of MacRuby, I would go for implicitness unless
>  there is a reason that the programmer needs to know the difference. If
>  we can define an official syntax (and semantics) for keyword arguments
>  that also helps MacRuby, I think that would be the optimal solution.
>
>  I would probably prefer one of the Smalltalkish variants as the standard:
>
>
>   duck foo: 1, bar: 2
>
>
> This plausibly conforms to current method semantics:
>
>   def duck(**kwargs)              # Implicit in the vcall
>     sym, arg = kwargs.shift
>     __send__ sym, arg, **kwargs
>   end

Except, as I understand the discussion, here duck is a variable
representing the receiver of a message with an objective-c message
selector of foo:bar: and which in Ruby might be written as:

class PotentialClassOfDuck
      def foo(first_arg, keywords={})

      end
end

I think that a reasonable Ruby parser would have a hard time seeing:

     duck foo: 1, bar: 2

as anything other that

    self.duck(foo:1, foo:2)

So I think we'd need to give it some help and write:

   duck.foo: 1, bar:2

which given optional parentheses might also be written(?):

   duck.foo(: 1, bar: 2)

but I'm not happy with either of those for several hopefully obvious
reasons having to do with the dependence on the presence or absences
of easily misread punctuation and whitespace.

-- 
Rick DeNatale

My blog on Ruby
http://talklikeaduck.denhaven2.com/