From: Eric Anderson <eric@...>
Date: 2005-01-09T04:16:36+09:00
Subject: Re: Type inference in ruby

Trevor Andrade wrote:
> I was wondering whether it would be possible to have a type inference system
> in ruby.  My question was asked before

I am sure it is possible to implement but I think most people end up 
wondering why do it? If you want a typed system (strong or weak) there 
are plenty of languages that support it natively. For me that is one of 
the reasons I left those other languages. For me a type system has too 
much coding overhead without much benefit. The two advantages are:

* Catches type errors
* Possibly better optimizations

To answer the first advantage Ruby encourages Unit testing. Unit testing 
it 10 times better than type checking because it can not only check for 
valid types but also check for logic errors. So why spend the overhead 
of a type system when unit testing is better.

The second advantage again isn't an issue for me. Ruby is fast enough. 
If I need it faster I can profile the code to find bottlenecks. If I 
need it even faster I can recode the bottlenecks in C. Again, the 
overhead of a type system is not worth even the possibility of better 
optimizations.

Just my two cents,

Eric