Re: others clause

[rogoff@sccm.Stanford.EDU (Brian Rogoff)]

geert@fozzie.sun3.iaf.nl (Geert Bosch) writes:
   Actually, one of the big dangers of object-oriented programming is
   that assumptions that hold for a base class do not necessarily
   hold for derived classes. Too many people think that OOP easily
   scales to large projects and that code reuse is safe, without
   even thinking about the possible problems.

Right. I think it is a problem that there are assumptions about 
signature, behavior, specification (pre/post condition), and protocols 
that have to be dealt with that are now mostly dealt with by comments. 
It would be great if something better than systematic commenting was 
available but I am not sure if it belongs in the core language, which 
is already a bit large.

   One of the features I'm really missing in Ada is a syntax to
   specify assertions, pre- and post-conditions and invariants for
   code and interfaces. Compilers wouldn't have to check these
   conditions, except some simple cases like static expressions,
   but they (or external programs) *could* check them and moreover
   compilers could use them for optimizations.

Do you think that this needs to be part of the language proper, or would 
add-on tools suffice? Wasn't Anna supposed to do fill this goal? Larch?
Standardizing an existing tool might be a reasonable interim solution. 

   Any new revision of Ada should address this issue, since it
   is so closely connected to the design goals of Ada.

Indeed.

-- Brian