From: Dave Thomas <Dave@...>
Date: 2001-08-05T23:08:25+09:00
Subject: [ruby-talk:19166] Re: My 1st look @ ruby: No prototypes and problem with String#gsub

stesch@no-spoon.de (Stefan Scholl) writes:

> Or is it common pratice to check these with defined?(data.[]) and
> defined?(data.length)? This way it's easier to find a bug when
> calling Shuffle#new with the wrong object.

The interpreter will find the bug for you, so I wouldn't bother.

There _are_ cases where I would check. One is when the actual call to
the method won't occur immediately. For example, observer.rb checks to
see that the parameter to add_observer responds to 'update'. This is
reasonable, because the actually call to update could happen
half-an-hour later. If that called failed, you may have lost context
in which to diagnose the problem. 

Regards


Dave