From: mark sparshatt <msparshatt@...>
Date: 2005-05-06T23:00:18+09:00
Subject: Re: nil.to_?  and  ruby2.0

Gergely Kontra wrote:
> Hi!
> 
> To the nil war:
> 
> Then what is the reason nil.to_i and friends exists?
> 
> Will it hide bugs?
> 
> I'm using 1.8, there nil.to_i exists,but
> a=nil
> b=2
> 
> b+a # nil cannot be coerced into Fixnum
> 
> So where to use nil.to_i?
> 
you'd use nil.to_i in a case like this

a = some_method
2 + a.to_i

if you knew that some_method could return nil and that treating it as 
zero was the right thing to do. I.E. if you've made a concious desicion 
to treat nil as zero

However if we allowed this

a = some_method
2 + a #=>

then whether or not it's reasonable for some_method to return a nil, it 
would still be silently handled whether you want it to or not.

So to_i and friends are there so a developer can use them to hide nils 
if the program warrants it, but this hiding isn't the default behaviour, 
so unexpected nils don't get hidden.

Which seems a reasonable compromise between flexibility and error detection.

--
Mark Sparshatt