From: "Martin J. Dürst" <duerst@...>
Date: 2013-11-12T10:04:26+09:00
Subject: [ruby-core:58285] Re: [ruby-trunk - Feature #6727] Add Array#rest (with	implementation)

On 2013/11/12 2:29, fuadksd (Fuad Saud) wrote:
>
> Issue #6727 has been updated by fuadksd (Fuad Saud).
>
>
> Reading back the comments, I realize Indexable may be a good idea for String/Array polymorphism.

The idea is already there. If you check, you'll notice that whenever 
something makes sense both for an Array and a String (e.g. #length), 
it's the same method with the same arguments. There is no explicit 
Indexable module or superclass because for efficiency, implementations 
are separate (and sharing implementations would be the main/only reason 
for using a module or a superclass in Ruby).

But there is also some aspect in which the two classes don't match. For 
Array, #each iterates over elements. But for String, #each doesn't 
exist. For the discussion in this issue, String#each would have to 
iterate over characters, but in Ruby 1.8, it iterated over lines, and 
that's why it was removed altogether from Ruby 1.9, and we have 
#each_char, #each_byte, #each_line now.

Regards,   Martin.