From: Greg McIntyre <greg@...>
Date: 2003-11-19T22:37:25+09:00
Subject: Re: Again, Rite explanation needed  (keyword args and new hash syntax)

matz@ruby-lang.org (Yukihiro Matsumoto) wrote:
> Basic Rule:
> Double asterisk for grouping the rest of keyword arguments.  Keyword
> arguments don't mix positional arguments (including optional ones).

Thanks for clearing that up! Is there some reason why you chose
double asterisks (**)? Are we running out of punctuation? :) To me it
seems a little too much like the * operator repeated.

  def f(*args); end
  f(**[[1,2,3]]) # => f(1,2,3) # logically, to me

But not so because we need ** to do this

  def f(**args); end
  f(**{:a => 1, :b => 2, :c => 3}) # => f(a:1,b:2,c:3)

Hmm... looks at keyboard for more punctuation... 

  def f(~args); end
  f(~{:a => 1, :b => 2, :c => 3}) # => f(a:1,b:2,c:3)

  def f(+args); end
  f(+{:a => 1, :b => 2, :c => 3}) # => f(a:1,b:2,c:3)

Isn't there a more natural syntax? Hmm...

  def f(a, b, [arguments])
    # arguments is an Array
  end
  f(a, b, 1, 2, 3)
  f(a, b, [1, 2, 3].arguments) # => f(a,b,1,2,3)

  def f(a, b, {keywords})
    # keywords is a Hash
  end
  f(a, b, x:10, y:20)
  f(a, b, {:x => 10}.keywords) # => f(a,b,x:10)

What do people think? I know * is borrowed from somewhere but it's not
very intuitive. As a university tutor, students always point at it and
say, "What's *that* do?"

-- 
Greg McIntyre ======[ greg@puyo.cjb.net ]===[ http://puyo.cjb.net ]===