From: Paul Brannan <pbrannan@...>
Date: 2002-04-16T21:17:22+09:00
Subject: Re: RCR: xx: yy as shorter notation for :xx => yy

On Tue, Apr 16, 2002 at 11:10:20AM +0900, Yukihiro Matsumoto wrote:
> Hmm, I was thinking to use "xxx: yyy" for keyword arguments in the
> future release.  But this one too is intresting.  I'd like to hear
> opinion from others.

From the few posts we have so far, it sounds like mixing the two would
be tricky (and possibly painful on the programmer).  If I have to choose
between the two, I think I would take keyword arguments, since there is
more to be gained.

One possibility for mixing them could be, though:

  x = Hash[
    foo: 1
    bar: 2
  ]

Hash[] would be defined as simply:

  class Hash
    def self.[](*args, **kargs)
      raise ArgumentError if args.size > 0 and kargs.size > 0
      return kargs if args.size == 0
      # else follow old logic for Hash[]
    end
  end

Here, **kargs is a Hash containing the leftover keyword arguments
(mapping Symbol to value).

Paul