From: pongba <pongba@...>
Date: 2007-09-02T21:50:16+09:00
Subject: How does ruby handle overloading?

Matz once replied on Cedric's blog that

I am not against "method overloading", but it very easily leads to
optional static typing in the language, which changes the language
very drastically, since you need to specify "type" to overload
arguments. Without well-thought design, it can "destroy" the language
and its culture. I have not yet got that well-thought design of method
overloading.

This is a very general argument, what concerns me is that if, for
instance, we have Matrix and Graph, and we'd like to be able to draw
both of them (the two 'draw's would have the same semantic but
different implementation logic), how 're we going to be able to
overload draw on Matrix and Graph like what we do in C++ or Java:

void draw(Matrix);
void draw(Graph);

One might argue that 'draw' should actually be a member function of
Matrix and Graph so the problem is moot. But then there's two more
problems:

1. if we can't modify Matrix or Graph, and writing a non-member 'draw'
is the only thing we can do to extend the interface of them, and we
actually can write 'draw' in terms of the public interface of Matrix
and Graph.

2. if '1' doesn't matter (because in ruby we actually can add new
methods to an existing class), then can you please give another more
qualified example?