From: John Carter <john.carter@...>
Date: 2006-02-17T06:22:23+09:00
Subject: Re: OT: Is this worth a try?

On Thu, 16 Feb 2006, Jens Auer wrote:

>> You find run time bugs much faster that way.
> Design by contract is a little bit more than placing asserts at the beginning 
> and end of a method. I would be realy glad if someone points me to some 
> library wich implements DbC completely in Ruby, eg the fact that a method can 
> only widen the supermethod's contracts which is automatically checked.


http://www.rubycentral.com/downloads/dbc.html

I don't think that does quite all you want, but I find I get 90% of the 
value I need out of static type checking, polymorhic type checking and DbC
by very very simple roll you own oneliners..

class Boo
   def bah( goo)
     raise "Whinge" unless expression && goo.responds_to? :glue_it

     invariant
     #do stuff
     raise "Whinge" unless post_expression
     invariant # If I'm paranoid
   end

   def invariant
     raise "Moan" unless invariant_expression
   end
end



John Carter                             Phone : (64)(3) 358 6639
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