On Wed, 29 Mar 2000, Andrew Hunt wrote:

[..]

> Somehere here I have a paper on Eiffel-like assertions in Smalltalk
> (I think it was from a university in Spain), I'll see if I can
> dig that up.

http://www.elj.com/elj.cgi?article=19990227c
http://apolo.lcc.uma.es/~ernesto/pubs/ps/tools94.ps.gz

[Eiffel/DbC/Paper] Eiffel-like Assertions and Private Methods in Smalltalk 
by M. Carrillo, J. Garca, E. Pimentel 

   ``Abstract: In this paper, we describe the current state of a project 
   whose aim is the extension of the Smalltalk environment by 
   incorporating mechanisms and tools promoting the development of quality 
   software. We have included in the Smalltalk context a number of 
   possibilities, which were not available in the original definition of 
   the language. In this sense, assertions can be specified in our 
   extension, in an Eiffel-like style, so gaining all benefits that the 
   use of assertions bring with them. We also propose an approach to 
   declare private methods, so that the information hiding capability of 
   Smalltalk is improved. These mechanisms are integrated with a new 
   browser and documentation tools increasing the understanding of the 
   class behaviour. The extension has been made by maintaining the 
   Smalltalk philosophy; that is, all elements incorporated to get the new 
   characteristics are defined only using Smalltalk components. ..'' 

More DbC links are here:

   http://www.elj.com/elj.cgi?search=dbc

   http://www.elj.com/elj.cgi?search=contract
   -- you will find some Python related links here

and here:

   http://www.elj.com/#design_by_contract

> I find DBC to be an amazing tool to find obscure bugs, and 
> even just *thinking* about what the preconditions and invariants
> for a class should be is a huge help.

Yep, it is a pity that Eiffel has been so universally rejected by the main
stream software development community.

Geoff Eldridge

-- geoff / elj.com
-- http://www.elj.com/elj-daily.cgi