Re: Ada exception block does NOT work?

[Robert A Duff <bobduff@shell01.TheWorld.com>]

Maciej Sobczak <no.spam@no.spam.com> writes:

> Jeffrey R. Carter wrote:
> 
> > Ada has had exceptions, well integrated with the rest of the language,
> > since Ada 80. Ada's terminology is that exceptions are raised and
> > handled.
> 
> OK, but the question is not about terminology, really.

By the way, here's a more subtle terminology difference:

What Ada calls "an exception" is what some other languages call "an
exception type" or "an exception class".  What Ada calls "an exception
occurrence" is what other languages call "an exception" (i.e. "an object
of an exception type/class").

And by the by the way, here's an analogy:

In very-early versions of Ada (the Green language), tasks were a
separate gizmo.  The designers of Ada 83 wisely chose to make tasks be
more integrated with the rest of the language -- to create a task, you
declare an object of a task type, or create a heap object of a task type
using "new", just like other sorts of objects are created.

In Green, there was something called a "task family", indexed by
integers.  In Ada, you simply create an array of tasks.  This is both
simpler (no need for a separate "task family" concept) and more general
(you can create any other sort of data structure using tasks -- arrays
of pointers to variant records containing tasks, etc).

I wish exceptions were treated the same way, with first-class exception
types and exception objects.  This would be both simpler and more
general.

- Bob

P.S. Regarding tasks, they didn't go quite far enough.  For example, why
do we say "task type T is..." instead of "type T is task..." like all
the other kinds of types?