From: Daniel Berger <Daniel.Berger@...>
Date: 2005-11-03T00:28:50+09:00
Subject: Re: ruby-dev summary 27393-27541

Minero Aoki wrote:
> Hi all,
> 
> This is a summary of ruby-dev #27393-27541.

<snip>

> [ruby-dev:27417] selector namespace
> 
>   Shugo Maeda proposed a new language feature, "selector namespace".
>   Matz also noted this topic in his key note at Ruby Conference 2005.
> 
>   Selector namespace is a namespace of selector (method name).  This
>   function is useful to replace methods temporarily.  For example,
>   current jcode.rb replaces String#chop itself, which effects globally.
>   But with selector namespace, it effects only in "jcode" namespace.
> 
>     class String
>       def jcode$chop   # define #chop method in jcode namespace
>         ...
>       end
>     end
> 
>     # "\244\242\244\244" is Japanese characters 'A'+'I' in EUC-JP
>     p "\244\242\244\244".chop         # "\244\242\244"  # wrong result
>     p "\244\242\244\244".jcode$chop   # "\244\242"      # right result
> 
>   You can omit namespace specifier ("jcode$") by using "using" syntax:
> 
>     class String
>       def jcode$chop() ... end
>     end
> 
>     using jcode
>     p "\244\242\244\244".chop   # "\244\242"      # right result
> 
>   There are still many arguments, for example:
> 
>     * whether "using" effects statically or dynamically
>     * '$' is ugly
>     * scope of "using" (file level / module level / method level)
>     * whether spaces are allowed around '$'

For those interested, Sydney will accomplish selector namespaces via Behaviors. 
  The exact syntax isn't settled yet, but you can look at 
http://www.livejournal.com/users/djberg96/50830.html for some ideas (and follow 
the link at the bottom to see the actual code).

I definitely prefer a block level approach.  I think Evan is leaning towards 
the "object.method using :namespace" syntax.

Regards,

Dan