From: Dave Thomas <Dave@...>
Date: 2002-08-28T06:38:24+09:00
Subject: Re: compile time type checking

"Volkmann, Mark" <Mark.Volkmann@AGEDWARDS.com> writes:

> Would you agree that with Ruby you have to write more unit tests
> than you do in Java?

Per function delivered? No, I don't think so. For example, the Java
equivalent of

    names = people.map {|p| p.name }

would probably merit a unit test. In Ruby it doesn't.  I'd say my
productivity is still way ahead in Ruby. Even testing is easier, as I
don't have to worry about producing complex mock environments.

> You need to test that the types of parameters being passed to every
> method are what was expected. It seems that this would cut into the
> productivity gains in writing the actual code when compared to Java.

Why would I need to check the types of parameters? (Or, I guess more
accurately, I've never felt the need to check the types of
parameters).  It just isn't a problem that crops up in my experience.

> I really want to be convinced that this whole type checking thing is
> a non-issue for Ruby, but I'm not quite there yet.

I was there with you: I came from a strong-typing background and
looked askance at languages such as Ruby and Smalltalk. Experience
writing large Perl programs only reinforced my biases. However,
writing Ruby code has made a convert of me. I'm just finishing a
fairly large Ruby web application (22kloc of Ruby, which is just below
the sentient level). The only time I missed compile-time type checking
was when I made major refactorings and wanted to ensure I'd changed all
the uses of a particular class. However, I still feel that there's no
way I could have delivered this kind of functionality this quickly in
(say) Java.

My advice (having been there) is to try it. Give it a number of
months, and try doing a decent sized project. Then form a personal
opinion. There's no correct answer: it comes down to personal
preference.



Cheers


Dave