Re: Proliferation of Reserved Words

["Randy Brukardt" <randy@rrsoftware.com>]

At least twice it was proposed that Ada have "keywords", identifiers with 
special meaning in the syntax but that were not reserved. The last time (and 
I forget precisely when that was), the ARG had a slight majority in favor of 
unreserved keywords as well as reserved words. However, it was resoundly 
rejected at the WG 9 level. At that time, WG 9 still voted by countries, and 
it turned out that pretty much everyone in favor of unreserved keywords were 
from North America. Most Europeans were appalled. Of course, that meant a WG 
9 vote with 2 in favor and a large number against.

So whenever you think there are too many reserved words in Ada, be assured 
that it was repeatedly suggested that they not all be reserved, but certain 
countries would not allow it. At this point, we've given up, since it really 
would not help much - the majority of words that likely ever be reserved 
already are (it would most likely matter if a new proposal tried to reserve 
some commonly used term - "yield" came up some some proposals for Ada 202x 
that didn't go anywhere).

Jeff Carter should note the 8 different uses for "with" in the syntax before 
he accuses anyone of not reusing reserved words in Ada. It's just the case 
that it's hard to write something meaningful with the existing reserved 
words (we almost always try).

"parallel" is an interesting case. In my world view, it is wildly different 
from a task, because it is *checked*, does not *block* or *synchronize* with 
another thread (all synchronization is via objects or completion), is 
automatically created (in looping constructs) and therefore requires 
substantial less care than writing a task.  There is another world-view 
where essentially the checking is not worthwhile and ergo must be 
suppressed, that performance matters to the point at which a compiler isn't 
allowed to make choices, and essentially requires *more* care than a task. 
In that second world-view, parallel constructs are either harmful or 
worthless. But even there, having a keyword makes it a lot easier to avoid 
them than trying to figure out which libraries to block. :-)

                                                   Randy.

"Dmitry A. Kazakov" <mailbox@dmitry-kazakov.de> wrote in message 
news:s93kci$1f55$1@gioia.aioe.org...
> On 2021-05-31 22:51, Jeffrey R. Carter wrote:
>
>> What do others think? Should Ada have made a greater effort at 
>> overloading reserved words from the beginning? Should we belatedly object 
>> to adding parallel when we have so many choices already? Or is having a 
>> large set of reserved words, many of them with similar meanings, a good 
>> thing?
>
> I believe that most of reserved keywords can be simply unreserved. 
> Actually there is no syntactic necessity except for few. The rest is kept 
> reserved for the sake of regularity only.
>
> -- 
> Regards,
> Dmitry A. Kazakov
> http://www.dmitry-kazakov.de