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From: jcm@hgc.edu (James McKim)
Subject: Re: Eiffel and Java
Date: 1996/10/31
Message-ID: <1996Oct31.201748.29073@merlin.hgc.edu>#1/1
X-Deja-AN: 193953094
sender: usenet@merlin.hgc.edu (Action News Central)
references: <550sm2$sn1@buggy.news.easynet.net>
 <mheaney-ya023180002810962151220001@news.ni.net>
 <55639c$1of@buggy.news.easynet.net>
organization: The Hartford Graduate Center
newsgroups: comp.lang.eiffel,comp.lang.ada
Date: 1996-10-31T00:00:00+00:00
List-Id: <comp.lang.ada>


In article <55639c$1of@buggy.news.easynet.net> Sacha@easynet.fr (Vincent WEBER) writes:
>In article <mheaney-ya023180002810962151220001@news.ni.net>, mheaney@ni.net 
>says...
>

[..]

>
>>
>>Ada's type mechanism accomplishes the equivalent of pre- and
>>post-conditions, and you don't seem to mind their inclusion in Eiffel, so
>>that can't be it.
>
>Well, to some extent... I admit you can easily use pre and post conditions in 

Whoa, about the simplest precondition I can think of is related to accessing
the top of a generic stack.

class STACK[G]
...
  top : G is
  require
    not_empty: depth > 0
...

How do you emulate this using types in Ada? 

>Ada, although maybe in a less elegant way. But in Ada It may be difficult to 
>emulate an invariant :)

>>
[..]

Just askin'
-- Jim

-- 

*------------------------------------------------------------------------------*
Jim McKim  (860)-548-2458     Teachers affect eternity. They can never tell 
Internet:  jcm@hgc.edu        where their influence stops.