Non-null objects, the Null Object pattern, and T.init

bearophile bearophileHUGS at lycos.com
Sun Jan 19 03:30:00 PST 2014


Jacob Carlborg:

> I think nil (null) works quite nicely in Ruby. nil is a 
> singleton instance of the NilClass class. Since it's an object 
> you can call methods on it, like to_s, which returns an empty 
> string. It works quite well when doing web development with 
> Ruby on Rails. If you're trying to render something that's nil 
> you'll get nothing, instead of crashing that whole page. Sure, 
> there might be a small icon or similar that isn't rendered but 
> that's usually a minor detail. If the page is working and main 
> content is rendered that's preferable.

Walter is arguing against this solution in D.
While that can be OK for Ruby used for web development, for a 
statically typed language meant for safe coding styles, there are 
better type-based solution to that problem.

Bye,
bearophile


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