From: Yusuke ENDOH <mame@...>
Date: 2010-03-12T12:25:00+09:00
Subject: [ruby-core:28622] Re: [Bug #1893] Recursive Enumerable#join is 	surprising

Hi,

2010/3/12 Yukihiro Matsumoto <matz@ruby-lang.org>:
> We should do something:
>
>  (a) revert and remove Enumerable#join altogether, leaving Array#join.
>  (b) make Enumerable#join not to join recursively; I think Array#join
>     should remain recursive join for array elements.


Thank you for remembering the issue!
But I like: (c) revert it and leave Enumerable#join.

I think Enumerable#join is irrelevant and innocent.
Why should Array#join flatten Enumerable object if there is
Enumerator#join?  Not because Enumerator is similar to Array?

If Enumerator is similar to Array, (c-1) Enumerator#to_ary
should be defined.
Otherwise, (c-2) merely Array#join should not call to_a to
flatten Enumerator.

I still prefer (c-1), though you rejected it once.

I admit (c-1) is slightly aggresive against compatibility
(for example, [] + [].to_enum now works!), so I would agree
with (a) or (b) as temporal solution.

-- 
Yusuke ENDOH <mame@tsg.ne.jp>