Question

I was working with Ruby and WIN32OLE (which is specifically, Excel).

I found all those enumerable objects, such as Range.Columns, are automatically enumerable in Ruby, and can be iterated using obj.each method.

I am wondering how it works? I understand that if you want to make something enumerable, you have to include "Enumerable". But apparently they cannot put that line in the OLE object. Is it just directly mapping obj.each method to for each loop?

Answer 1

There’s an interesting set of posts here that might answer your question, specifically:

(…) each is called as
dynamically as any other OLE method; it’s not determined before the
call whether or not the object actually implements IEnum.

and:

Enumerable#find method clashes the ‘find’ method of Excel Range
object. This is the (only) reason why WIN32OLE does not include
Enumerable.

WIN32OLE class has ‘each’ method (WIN32OLE#each is defined) (…)

Hope this helps!