From: Shugo Maeda <shugo@...>
Date: 2011-10-07T13:00:28+09:00
Subject: [ruby-core:40015] Re: problems with Refinements

Hi,

2011/10/7 Steve Klabnik <steve@steveklabnik.com>:
> �Cons:
> �- End up making libraries harder to understand, since the details of
> MyLibrary's String are opaque from outside MyLibrary

At this point, I think refinements are better than monkey patching
because affection of refinements are limited lexically.

> �- Are a pretty complex feature to use.
> �- This complexity makes code with refinements hard to reason about.

I admit that refinements are complex, but refinements are a feature
for advanced library/framework developers.
Most application programmers do not need to take care about the
complexity of refinements.

> Refinements for Ruby Implementors:
> �Pros:
> � �- Giving users a feature they want
> �Cons:
> � �- Complex features are complex to implement
(snip)
> � �- This feature affects Ruby at a very, very deep level, and
> therefore deserves significant consideration

Agreed.

I guess implementations other than CRuby have last_class in stack
frames, so for their implementors it may be easier to implement
refinements than CRuby:)

> � �- Refinements in particular place a large burden on send (I
> think), which is what makes the performance penalty so large.

I guess the performance decrease came from the change of stack frames,
so implementations other than CRuby may not be affected.

> Many people _do_ want refinements, but that doesn't mean that it's
> good for Ruby.

Agreed.  I think Matz should finally decide.

-- 
Shugo Maeda