From: Gavin Kistner <gavin@...>
Date: 2006-01-17T00:12:28+09:00
Subject: Re: basic question about Fixnum & Integer

On Jan 16, 2006, at 8:05 AM, Daniel Harple wrote:

> On Jan 16, 2006, at 4:01 PM, Daniel Harple wrote:
>> You must require 'mathn'
>
> Actually, this is partially wrong. #lcm is defined in rational, but  
> mathn requires rational. So require 'rational', but require 'mathn'  
> works too. Sorry.

Ah, so the documentation isn't wrong, it's just confusing.

Tom, the issue is that Ruby allows different libraries to modify and  
extend the same class. (So, Integer has a base set of methods  
included in the core, but including libraries like Rational adds  
additional methods.) Ruby's documentation system (RDoc) has the  
ability to conveniently merge the methods from all those libraries  
under the single class to which they belong. Unfortunately, it  
doesn't make clear which file or library each method comes from, and  
the people who wrote the documentation for these 'addon' methods did  
not make clear which library they came from.

Your confusion is certainly understandable.