From: Dan Schmidt <dfan@...>
Date: 2001-03-30T00:40:08+09:00
Subject: [ruby-talk:13327] Re: hash slice implementaion

matz@zetabits.com (Yukihiro Matsumoto) writes:

| In message "[ruby-talk:13318] hash slice implementaion"
|     on 01/03/29, "Hee-Sob Park" <phasis@hananet.net> writes:
| |
| | I'd like to use Perl's hash slice feature in Ruby.
| | Here is my implemetation of hash slice.
| | How about this code?
| 
| It's interesting.  The only reason hash#[] does not accept multiple
| argument for slice is consistency with array, which uses [] argument
| differently.  If consensus is made, I'd like to merge it.  But I
| doubt.

I made the suggestion recently that Array#[] and Hash#[] exhibit
slicing behavior when the argument is an Array (or any Enumerable,
maybe?  Array#[](aRange) already works like this).  So you would
need an extra pair of brackets if you specify the array argument
explicitly.  Would this eliminate ambiguities?

e.g.,

  h = {}
  h[1] = 'a'
  h[2] = 'b'
  h[[1, 2]] => ['a', 'b']
  a = [2, 1]
  h[a] = ['b', 'a']

It would mean that you couldn't use Arrays as keys to Hashes, but that
seems like a bad idea anyway.

-- 
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