From: Daniel Amelang <daniel.amelang@...>
Date: 2005-04-06T12:11:22+09:00
Subject: Re: Garden RubyNuby Question on parameters in blocks vs. methods

> I'm suprised that no one is offering an answer here, especially
> considering what's being said about the community's support of Nuby's
> in other threads.

Sorry, Trans, I just think that there are so many people on this list
that everyone figures someone else will answer.

That said, your original post isn't _that_ old. If you're looking for
real-time help, go to #ruby-lang on irc.freenode.net.

> Well, I'll take a small stab at the 2nd. Please correct me in so far as
> I am wrong: In future versions of Ruby block parameters and def
> parameters will work exaclty alike.

Although I think 1.9 will make them work more similarly that they do
now, I don't think they will ever work exactly alike. You can do some
stuff with block parameters that's pretty crazy. For example, you
don't have to 'accept' the arguments passed in:

def doit
  yield(1)
end

doit { puts "Look ma, no arguments!" }

And you can expand arrays:

def pass_array
  yield([1,2])
end

pass_array {|(first, second)| puts "First element: #{first}"}

I haven't seen anything that says that methods will have this same
behavior (although they can do some of the same things using different
syntax) Anyone else?

> As for the first. Why not "do (a,b) ... end" instead of "do |a,b| ...
> end" Well, without thinking about it to much, I imagine it is simply
> due to syntax ambiguities.

I've wondered about this one before. It would be _possible_ to change
the method definition to use pipes instead of parans, and not have
ambiguities (I think), but that's a pretty significant language
change. I guess they were just born that way, and it's too late to
change.

So, anyone else?

Dan