__noSuchMethod__ and direct proxies

Dmitry Soshnikov dmitry.soshnikov at gmail.com
Mon Dec 5 08:56:56 PST 2011

On 05.12.2011 20:20, John J Barton wrote:
> On Mon, Dec 5, 2011 at 2:48 AM, Tom Van Cutsem<tomvc.be at gmail.com>  wrote:
>> Hi,
>> There have previously been discussions on this list and elsewhere about
>> whether or not proxies cover the __noSuchMethod__ use case [1,2].
> ...
>> [1] https://mail.mozilla.org/pipermail/es-discuss/2011-October/017467.html
>> [2] https://bugzilla.mozilla.org/show_bug.cgi?id=683218#c8
> The references here discuss how proxies can/cannot implement
> __noSuchMethod__. Is there a use case for __noSuchMethod__? As in why
> would anyone want such a thing?

Dynamic abstractions. A real example Ruby on Rails' database lookup methods.

Say, you have a model with fields, [id, name, email], then in your db 
model you have methods:

db.find_by_name, db.find_by_email, etc. Once you add another field to 
your db, you automatically have its getter either.

And all these methods are virtual. Though, rails uses 
"once-called-virtual-method" approach. Which means the method (for 
efficiency) will be created on object/prototype.


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