From: Chris Cummer <chris@...>
Date: 2007-12-20T03:15:12+09:00
Subject: Re: [Rhetoric] Two feature requests for safer Ruby Programming


On 19-Dec-07, at 6:18 AM, Sylvain Joyeux wrote:

>> I was aware of this, but what I also meant was:
>>
>> class WarningAlreadyExists
>>  def bla
>>  end
>> end
>>
>>
>> class Foo < WarningAlreadyExists
>>  def bla
>>  end
>> end
>>
>> Doesn't give any warnings, even with warning flag on.
> Of course it does not. You may have to learn some basic object- 
> oriented
> principles before complaining about robustness issues in languages.
> Reimplementing a method in subclasses is the basis of polymorphism and
> is the way to go in *all* object oriented languages I know of.

Sylvain is correct. The "danger" you're objecting to here is in fact  
exactly the desired behaviour.

Often a programming language can protect a developer but in this case,  
if the over-riding were undesirable, then the error would be in  
extending a class that the developer does not yet fully understand,  
and not with the programming language.

Regards
Chris