From: Jim Weirich <jweirich@...>
Date: 2002-10-20T12:12:19+09:00
Subject: Re: Interfaces in Ruby

On Fri, 2002-10-18 at 14:08, Nat Pryce wrote:

> [...] Also, in my experience, DbC ends up polluting the class
> interface with a lot of predicates, because it doesn't support the idea
> of protocols, [...]

I'm not sure I understand the above comment.

> [...] and makes changing code very difficult because contracts
> are duplicated throughout the code. 

Really?  In my experiance, the contract normally gets specified in the
most abstract class, and there is little need to repeat it.  Subclasses
only express modifications and refinements to the contracts they
inherit.

-- 
-- Jim Weirich     jweirich@one.net    http://w3.one.net/~jweirich
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"Beware of bugs in the above code; I have only proved it correct, 
not tried it." -- Donald Knuth (in a memo to Peter van Emde Boas)