comp.lang.ada
 help / color / mirror / Atom feed
From: volkert@nivoba.de (Volkert)
Subject: Re: ANN: SPARK Book - Sample Chapters now free on-line
Date: 1 May 2003 05:54:51 -0700
Date: 2003-05-01T12:54:52+00:00	[thread overview]
Message-ID: <d37844cb.0305010454.15422cb7@posting.google.com> (raw)
In-Reply-To: vaqcvcruvo1493@corp.supernews.com

"Neil Groves" <neilgroves_no_spam@dial.pipex.com> wrote in message news:<vaqcvcruvo1493@corp.supernews.com>...
> I thought that SPARK required contra-variance which is fundamentally
> incompatible with the covariance in Eiffel?
There is no concept of contra-/co-variance in Spark. 
As i understand Spark, the redefinition of a procedure (method) 
in a child of a tagged type (class) must have >>exactly<< the 
same procdure signature as given with the parent type. A very 
strong conformance rule, but remember: Spark has NO references (entities) 
and NO dispatching (class wide types with offers you dynamic binding)

Volkert



      parent reply	other threads:[~2003-05-01 12:54 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2003-03-11 16:26 ANN: SPARK Book - Sample Chapters now free on-line Rod Chapman
     [not found] ` <878yvl3khn.fsf@fbigm.here>
     [not found]   ` <uel5b6ocq.fsf@xsol.com>
     [not found]     ` <vaqcvcruvo1493@corp.supernews.com>
2003-05-01 12:54       ` Volkert [this message]
replies disabled

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox