From: Rick DeNatale <rick.denatale@...>
Date: 2006-09-06T04:34:40+09:00
Subject: Re: Best way to do helpers for a constructor

On 9/5/06, Jason Merrill <jason.merrill@yale.edu> wrote:
> What is the best practice for creating helper methods for a
> constructor?  In Java (not that I know that much about Java), my
> instinct would be to make helper methods for a constructor be private
> class methods, since they generally don't rely on the state of the
> object being created.  In Ruby, however, it seems you're not allowed
> to call private class methods from within instance methods.

But unlike Java, Ruby doesn't have constructors, instead it has class
methods new and allocate which are rarely overidden.

The standard new method calls allocate to get storage for the instance
and then 'sends' initialize to the instance, using a non-standard
mechanism.

So I'd just make the helper methods private instance methods. Since
initialize itself is an instance methods it will work.  There's
nothing written in stone saying that an instance method should rely on
instance state.

IMHO this difference between Java and Ruby is a good thing.  Ruby
doesn't have "tyrannical constructors" as Martin Fowler put in his
article on Rake.

-- 
Rick DeNatale

My blog on Ruby
http://talklikeaduck.denhaven2.com/