From: "Adam P. Jenkins" <thorin@...>
Date: 2005-07-21T01:05:55+09:00
Subject: Re: Ruby/Rails as a starter language?

Kev Jackson wrote:
> The example of polymorphic dispatch could be done in Java, but only 
> just, and as this post suggests, with a load of reflection trickery - 
> pass in Class, get all the methods, find method named 'foo', create new 
> Method object, invoke and voila.

It's just a two-liner in Java instead of a one-liner like in Ruby.  I 
don't know where you and Devin are getting this idea that you need to 
"make extensive use of the Reflection API" and a "load of reflection 
trickery" to write polymorph or similar kinds of things in Java.  Here 
it is, and I think it's very straightforward, if a bit more verbose than 
the equivalent Ruby code:

Object polymorph(Object snufkin) throws Exception {
   Method m = snufkin.getClass().getMethod("foo", null);
   return m.invoke(snufkin, null);
}

Certainly Java wasn't designed to make duck typing convenient, but it 
does have quite a powerful and useful reflection API, which allows about 
as much of the Ruby reflection capabilities as makes sense in a 
statically typed language.

Adam