From: "trans.  (T. Onoma)" <transami@...>
Date: 2005-01-14T05:50:30+09:00
Subject: Re: Duck Typing as Pattern Matching

On Thursday 13 January 2005 01:06 pm, itsme213 wrote:
| Not sure what "upon" is. If your intent is to associated distinct
| method_missing handler procs with selectors, so that Object#respond_to? can
| utilize this properly, it can be done in many ways. e.g. Object could
| provide a register_method_missing_handler:
|
| class MyClass
|     register_method_missing_handler :selector, { |*args| handler }
| end
|
| Then Object#respond_to? could utilize the registered selectors.
|
| One difficulty would be generic handlers (e.g. a proxy handles anything its
| real target does, OpenStruct handles any x() and x(y)), so the "associated
| selectors" would need to include something like pattern matching or
| wildcards. Oh, oh, ... does that mean we are back to duck typing based on
| pattern matching ? ;-)

Of course ;) And that's why I used "upon" and not just a case statement or 
secondary "respond_if" method to invoke a method_missing handler.

T.

P.S. Of course the coolest of cool would be if Ruby were so reflectively 
powerful as to allow for true method probing. Then Ruby could simply probe 
#method_missing and determine if it responds. But of course, that's _so cool_  
b/c in fact it may not even be possible.