From: Daniel Berger <djberg96@...>
Date: 2006-12-30T10:55:08+09:00
Subject: Re: Using an UnboundMethod instead of an alias to redefine a method


Mauricio Fernandez wrote:
> On Wed, Dec 27, 2006 at 11:30:05PM +0900, Daniel Berger wrote:
> > I came across a technique for aliasing methods that I have never seen
> > before [1] and was just too good to pass up.  But first, the setup.
> [...]
> > So, now our custom Hash#[]= method is bound to an UnboundMethod that no
> > one else has access to (see the first link below for a better
> > explanation).  Pretty neat, eh? Is there any downside to this approach?
> > If not, it seems this technique ought to be filed under 'best
> > practices', and perhaps even abstracted somehow in the core itself.
> >
> > Many thanks to Jay Fields [2], whose blog entry led me back to the
> > original entry by Martin Traverso.
>
> That technique is fairly old (I myself tried to popularize it a few years
> ago). It's cleaner & generally safer than alias_method, but there are three
> shortcomings:
> * the environment captured by the closure is often too heavy (extra care
>   needed to get rid of unwanted references is needed)

How can we lighten it, if at all?

> * a method defined with define_method+block cannot take a block under 1.8
>   (it's possible in 1.9, though)

Hm, that is a limitation, but at least the simple cases still work.

> * method calls are much slower

Yes, I saw some of the benchmarks.  Maybe we could memoize the binding
somehow? I don't know if that even makes sense.  I'm just tossing ideas
out there.

I guess for now I'll live with making my private aliases...private. :)

Regards,

Dan