From: Joel VanderWerf <vjoel@...>
Date: 2004-01-27T07:39:00+09:00
Subject: Re: def foo[](x)

Gavin Kistner wrote:
> David Heinemeier Hansson wrote:
> 
>> I've been puzzled by this myself. There has been many times where I've 
>> wanted to fake the appearance of a collection within a class without 
>> actually making another class just for the purpose.
>>
>> Could this perhaps make it in as an RCR?
> 
> 
> I'm glad I'm not the only one. I have now added this as an RCR:
> http://www.wobblini.net/rcr/RCR/RCR201

Question: in this method call:

   x.foo[1]

what is the search order? First for #foo, and then for #foo[]? Or the 
other way around?

Suppose it's #foo, then #foo[]. What if #foo is implemented in the 
superclass, but #foo[] is implemented in the class of x itself? In other 
words, depth-first search or breadth-first search?

It seems difficult to resolve the ambiguities inherent in this notation. 
(But I have sometimes wished this feature existed.)