Re: Non-philosophical definition of Eiffel?

[Hyman Rosen <hyrosen@mail.com>]

Alexander Kopilovitch wrote:
>   So, is there a definitive book about Eiffel programming language, but without
> too many pages about Design By Contract?

Go right to the horse's mouth, _Object Oriented Software Construction_
by Bertrand Meyer. In my opinion, the huge error made by Eiffel is to
have covariant argument types for inherited methods, and this as an
error from which the language has never recovered.

For those unfamiliar with the concept, Eiffel allows a derived class
to override an inherited method with a method whiach takes a more
restricted argument type. This obviously causes huge correctness
issues, since at any call using a base object you may be committing
a type violation that you are not even aware of! The Eiffel people
have spent years trying to figure out ways around the problem while
still keeping the original design.