From: Mark Wilson <mwilson13@...>
Date: 2003-02-13T12:10:18+09:00
Subject: Re: von Rossum on Strong vs. Weak Typing

It is interesting and consistent with Python's design that Guido von 
Rossum speaks in terms of writing and testing functions and nowhere 
mentions methods.

On the issue of typing (as in type of object) as I understand Ruby:

1. Ruby is strongly-typed, meaning that if an object receives a method 
that it cannot respond to, it will generate a type error if the method 
belongs to a built-in class, or a method missing error otherwise.

2. Ruby is dynamically typed, meaning that variables (references to 
objects) are not typed and type is checked when a method is applied to 
the object.

3. The future of Ruby will de-emphasize the term type and instead look 
at whether an object responds to method calls.

4. Also, as I understand the concept of type, at least in the context 
of Ruby, it is really talking about class. The type of an object being 
defined by the methods it responds to means that the type is described 
by the class, because the class includes the collection of methods that 
can be used on the object.

5. Note that the traditional primitive types (string, array, numeric) 
are classes in Ruby, and can be extended in a program. I'm also trying 
to say that with types = classes typing can be stronger than what just 
providing primitive types provides.

Please feel free to correct the above if you think I've gotten it wrong 
;-)