Re: Some questions about Ada.

[Laurent.Guerby@enst-bretagne.fr (Laurent Guerby)]

Richard Kenner writes
[talking about casing]
: A counterexample to that, with which I mostly agree, are some C coding
: conventions where the kind of thing is determined by the casing of the
: first letter.  I've seen this sort of thing in the sources of some CAD
: systems.  For example:
: 
: typedef struct wire {...} Wire;
: typedef struct signal {...} Signal;
: 
: I've also seen this done with macros that call functions vs the function
: they, internal and external versions of a function, etc.
: 
: I think this can be a very useful convention if it is followed
: uniformly.  I can't offhand think of an Ada analog for such a
: convention, though.

   For this  kind of  macros,  the Ada equivalent  is Inline (standard
since the good old days ;-) and a good compiler :  nightmare for a few
compiler writers, easy and maintainable  for zillions of users, sounds
like the optimal  scheme in language  design for me (IMHO, but there's
of  course counter arguments,  like time to market  a  compiler, but I
think the Ada world is not the same than in the eighties and has taken
into account previous mistakes and experiences).

   For the useful casing convention, from a safety point of view, it's
hard  to rely on  a single letter for  such a semantic gap. IMHO, just
adding a _Type if no  good name can be found  is better (I've not said
"the best") and safer.

   But I agree that if strictly everybody  on a large project agree on
such a uniform convention, it can work. This is not common case.

   On the  mathematical side, I've seen a   lot of stupid  but hard to
find mistakes (including my own  ones ;-) introduced by the convention
"x"  "X" "i"  etc ...  For  my own  calculus  I started to use  longer
indices (i_something), so when  I discovered Ada,  I was very happy to
type   five  more characters a  few   times instead  of spending hours
reading obscure things to   find a typo.  I've  choosen to agree  with
case-insensitivity for programming languages on the  same basis, and I
don't rely a priori on casing for meaning.

-- 
--  Laurent Guerby, student at Telecom Bretagne (France), Team Ada.
--  "Use the Source, Luke. The Source will be with you, always (GPL)."
--  http://www-eleves.enst-bretagne.fr/~guerby/ (GATO Project).
--  Try GNAT, the GNU Ada 95 compiler (ftp://cs.nyu.edu/pub/gnat).