From: Gregory Seidman <gsslist+ruby@...>
Date: 2007-03-21T10:25:20+09:00
Subject: Re: does Ruby not support multiple "initialize" methods for a class???

On Wed, Mar 21, 2007 at 10:09:36AM +0900, Chad Perrin wrote:
> On Wed, Mar 21, 2007 at 08:32:37AM +0900, johan556@gmail.com wrote:
> > On 3/20/07, Greg Hauptmann <greg.hauptmann.ruby@gmail.com> wrote:
> > >Hi,
> > >
> > >Q1 - Does Ruby not support multiple "initialize" methods for a class?
> > >
> > >Q2 - If no is there a reason for this out of curiosity?
> > >
> > >Q3 - What approach is recommended if this constraint does exist?
> > >
> > 
> > I have been using the following pattern to implement multiple
> > constructors for a class. It is only a variation of the already
> > proposed solutions, but by using "instance_eval" I could avoid having
> > to create separate new/initialize-like methods for each constructor.
> 
> I've heard it said -- and I tend to agree -- that regular use of
> "patterns" is a sign that the language lacks something.  I wonder if
> that is the case with Ruby, as applies to multiple constructor behavior
> implementation.
> 
> I say "wonder" because I really am not certain in this case.

Well, it's a choice. You can either have overloading or dynamic typing, but
not both. The "pattern" is just a matter of having different names for your
constructors. The simple, common case of a single constructor is supported
by the new/initialize separation, but multiple constructors are still
pretty easy. Note that Objective-C, another Smalltalk-like,
dynamically-typed language, uses the same pattern.

> CCD CopyWrite Chad Perrin [ http://ccd.apotheon.org ]
--Greg