Re: Interface/Implementation (was Re: Design by Contract)

[nospam@thanks.com.au (Don Harrison)]

Joerg Rodemann wrote:

:Don Harrison (nospam@thanks.com.au) wrote:
:> :* Interface control and verification -- the Ada spec can be written
:> :  and published, and other groups can code against it.  If the
:> :  implementation or the client changes, the compiler can verify that
:> :  they are still consistent without having to reprocess both.
:
:> Possible in any IDE supporting freezing of short forms.
:
:> :* Multiple implementations, global, compile time -- you can have
:> :  many implementations of your package spec, and select the best
:> :  one for your application at compile time.  Thus, your "list"
:> :  could have a hash table for faster lookup, or store its contents
:> :  to disk to allow long lists of huge data items (just one in
:> :  memory at a time), or whatever -- as long as the spec stays the
:> :  same, the client code doesn't need to be recompiled.
:
:> Possible in any IDE supporting multiple class texts.
:
:Well, twice you mention the need of an IDE...

Yes, only because I consider that to be the ideal way of developing. 
But, while a sophisticated IDE may be the optimal tool, it isn't actually 
*necessary*, as such.

Any of this CM-related or Change Control-related functionality can be done 
handraulically in the absence of such support from an IDE or if you have a 
preference for using particular tools not available through the IDE. This 
would involve writing some scripts to make the job easier but it wouldn't be 
difficult by any means.

:With Ada, to start working I 'just' need a compiler/linker combination.
:But from then on I AM able to work. Perhaps not with all the worlds luxuries
:and little add-ons and features, but it is possible. However, if I need
:a fully blown-up intelligent IDE, then I am lost.

If that's all you want, then you have that option. You can either use a 
sophisticated IDE or use a basic compiler/linker. For example, without 
intending any criticism, SmallEiffel (the free compiler), is basically 
just a command-line driven compiler. No doubt, people use it in conjunction 
with a variety of other tools.

:(Since I am sure there won't be any ports to some platforms I am 
interested in.)

Which ones are you interested in?

While none of the supported platforms are too esoteric, there are some realtime 
platforms, including VxWorks, for example. Also, there's an expressed 
willingness from some vendors to support others, presumably on the basis of 
demand. From ISE's recent announcement of "Embedded Eiffel":

   "- A version of ISE Eiffel 4 that runs on Windriver's
      VxWorks (TM) operating system for host-to-target
      development and debugging. This version can be adapted
      to other real-time operating systems.

      ...

    - Benefit from the portability of ISE Eiffel, running
      with identical source code on all major industry
      platforms including Windows NT, Windows 95, Unix
      (HP-UX, Solaris, SunOS, SGI, RS/6000, UnixWare etc.),
      Linux, VMS."

:Surely Ada has a better stand in here...

No doubt there are more embedded platforms currently supported by Ada but Ada 
vendors will also be limited by demand in terms of which they can support.


Don.                     (Reverse to reply)
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Don Harrison             au.com.csa.syd@donh