From: Daniel DeLorme <dan-ml@...42.com>
Date: 2006-07-10T22:42:50+09:00
Subject: Re: Enumberable fails for class Subclass < Array; def enum...

Laza wrote:
> Array includes Enumerable. But when a subclass of Array redefines
> each(), then Enumerable still refers to the original Array.each(). Why
> is that?

Your confusion is understandable but you've got the problem backward: that 
behavior is not because Enumerable uses Array's each, it's because Array defines 
its own version of collect. Look at Array's local (non-inherited) methods:

[].public_methods(false).sort
=> ["&", "*", "+", "-", "<<", "<=>", "==", "[]", "[]=", "assoc", "at", "clear", 
"collect", "collect!", "compact", "compact!", "concat", "delete", "delete_at", 
"delete_if", "each", "each_index", "empty?", "eql?", "fetch", "fill", "first", 
"flatten", "flatten!", "frozen?", "hash", "include?", "index", "indexes", 
"indices", "insert", "inspect", "join", "last", "length", "map", "map!", 
"nitems", "pack", "pop", "push", "rassoc", "reject", "reject!", "replace", 
"reverse", "reverse!", "reverse_each", "rindex", "select", "shift", "size", 
"slice", "slice!", "sort", "sort!", "to_a", "to_ary", "to_s", "transpose", 
"uniq", "uniq!", "unshift", "values_at", "zip", "|"]

I suppose it was done that way for optimization. Why do you need to subclass 
Array, anyway?

Daniel