Unusual syntax

Unusual syntax

[Steve Caddy]

I've been programming Ada95 for several years now, and have referred to
my copies of both Barnes and Skansholm in times of need. All has been
well... until I started working with a guy who has a copy of Skansholm
in Swedish.

Interestingly enough, his copy demonstrates the use of a case statement
with something like this...

when A ! B ! D => do_something;

...as opposed to what I'm familiar with...

when A | B | D => do_something;

I was even more amazed when the first version compiled and functioned in
the same way as the second version.

Has anyone come across this before? I've searched the LRM for clues, but
I can't find any other reference to this syntax. Please reassure me that
I'm not going mad!

Regards

Steve

--
Steven M Caddy, MEng -----------------------------------------------------
"Paediatrician?....Oh! A foot specialist!"
Email: dyn@m0ng.com

Re: Unusual syntax

[Florian Weimer]

"Steve Caddy" <dyn@m0ng.com> writes:

> I was even more amazed when the first version compiled and functioned in
> the same way as the second version.
>
> Has anyone come across this before?

It's documented in Annex J.  There are ASCII variants without the
characters {|}[\]~@ (a widely deployed system is videotex with
national code pages).

Re: Unusual syntax

[Randy Brukardt]

Steve Caddy wrote in message ...
>I've been programming Ada95 for several years now, and have referred to
>my copies of both Barnes and Skansholm in times of need. All has been
>well... until I started working with a guy who has a copy of Skansholm
>in Swedish.
>
>Interestingly enough, his copy demonstrates the use of a case statement
>with something like this...
>
>when A ! B ! D => do_something;
>
>...as opposed to what I'm familiar with...
>
>when A | B | D => do_something;
>
>I was even more amazed when the first version compiled and functioned
in
>the same way as the second version.
>
>Has anyone come across this before? I've searched the LRM for clues,
but
>I can't find any other reference to this syntax. Please reassure me
that
>I'm not going mad!

That's an obsolecent feature. See J.2 in the RM:
http://www.adaic.org/standards/95lrm/html/rm-j-2.html.

          Randy Brukardt.

Re: Unusual syntax

[Robert Dewar]

"Steve Caddy" <dyn@m0ng.com> wrote in message news:<wCTE8.4168> when A ! B ! D => do_something;
;
> 
> I was even more amazed when the first version compiled and functioned in
> the same way as the second version.

No doubt you will get a huge pile of answers telling you that the only problem
here is your unwarranted amazement :-)

But here is a constructive suggestion. Get an online version of the RM. When
you find something that surprises you, it is often trivial to track it down
with a search, as in this case, you could just search for ! and immediately
find the reference to this language features (which has been around in the
standard for nearly 20 years now!)

Re: Unusual syntax

[Steve Caddy]

"Robert Dewar" <dewar@gnat.com> wrote in message
news:5ee5b646.0205170201.2582c8ef@posting.google.com...

> But here is a constructive suggestion. Get an online version of the RM.
When
> you find something that surprises you, it is often trivial to track it
down
> with a search, as in this case, you could just search for ! and
immediately
> find the reference to this language features (which has been around in the
> standard for nearly 20 years now!)

I did think of searching my copy of the LRM (provided on an old BURKS CD),
but all I got was an unhelpful "this version of the LRM cannot be searched"
sort of message. So I guessed and looked at the syntax for a case statement.
When that didn't work, I rattled through the FAQ for this group for answers.
Still having no joy, I decided to post.

Anyway, thanks for all the help... you can't possibly imagaine the number
of coding standards issues this has turned up among the team I work in.
Fortunately it's Friday today, so after a coffee and a laugh, we decided
to leave obsolecent features in the graveyard that is the past.

These opens the question, will they actually be removed in a future
incarnation of Ada, or is backward compatibility that a vital feature to
Ada?

Steve

--
Steven M Caddy, MEng -----------------------------------------------------
"Paediatrician?....Oh! A foot specialist!"
Email: dyn@m0ng.com

Re: Unusual syntax

[Jeffrey Carter]

Robert Dewar wrote:
> 
> But here is a constructive suggestion. Get an online version of the RM. When
> you find something that surprises you, it is often trivial to track it down
> with a search, as in this case, you could just search for ! and immediately
> find the reference to this language features (which has been around in the
> standard for nearly 20 years now!)

Was this not in Ada 80?

-- 
Jeff Carter
"Monsieur Arthur King, who has the brain of a duck, you know."
Monty Python & the Holy Grail

Re: Unusual syntax

[Robert Dewar]

Jeffrey Carter <jrcarter@acm.org> wrote in message news:<3CE55D49.70638FEE@acm.org>...
> Robert Dewar wrote:
> > 
> > But here is a constructive suggestion. Get an online version of the RM. When
> > you find something that surprises you, it is often trivial to track it down
> > with a search, as in this case, you could just search for ! and immediately
> > find the reference to this language features (which has been around in the
> > standard for nearly 20 years now!)
> 
> Was this not in Ada 80?

Yes indeed, but this was not a standard. The first standard
was 1983, nearly 20 years ago. 

What was the exact date of the issuance of Ada 83.
Shall we have an anniversary party, or perhaps a reunion.
I would be willing to host such a party for all those
involved at the time :-)

Re: Unusual syntax

[Jeffrey Carter]

Robert Dewar wrote:
> 
> Jeffrey Carter <jrcarter@acm.org> wrote in message news:<3CE55D49.70638FEE@acm.org>...
> >
> > Was this not in Ada 80?
> 
> Yes indeed, but this was not a standard. The first standard
> was 1983, nearly 20 years ago.

Ada 80 was MIL-STD-1815, 1980 Dec. Sounds like a (MIL) standard to me.

> 
> What was the exact date of the issuance of Ada 83.
> Shall we have an anniversary party, or perhaps a reunion.
> I would be willing to host such a party for all those
> involved at the time :-)

ARM 83 (ANSI/MIL-STD-1815A) is dated 1983 Feb 17. Somebody named "R.
Dewar" is mentioned in the Foreword.

-- 
Jeff Carter
"You empty-headed animal-food-trough wiper."
Monty Python & the Holy Grail

Re: Unusual syntax

[Marin David Condic]

IIRC, it was a *draft* standard that was put out for purposes of getting
back comments and feedback on the language. It was never accepted as an
actual standard. (If memory serves, back in that draft, functions without
parameters had to have the "()" much like C/C++... Maybe the C hackers would
have liked it better? :-)

MDC
--
Marin David Condic
Senior Software Engineer
Pace Micro Technology Americas    www.pacemicro.com
Enabling the digital revolution
e-Mail:    marin.condic@pacemicro.com


"Jeffrey Carter" <jrcarter@acm.org> wrote in message
news:3CE812B1.492EF78E@acm.org...
>
> Ada 80 was MIL-STD-1815, 1980 Dec. Sounds like a (MIL) standard to me.
>

Re: Unusual syntax

[Jeffrey Carter]

Marin David Condic wrote:
> 
> IIRC, it was a *draft* standard that was put out for purposes of getting
> back comments and feedback on the language. It was never accepted as an
> actual standard. (If memory serves, back in that draft, functions without
> parameters had to have the "()" much like C/C++... Maybe the C hackers would
> have liked it better? :-)

That's right, subprogram calls with no parameters had to have an empty
pair of parentheses after them in Ada 80.

I'm no expert, but I think 1815 was a standard. That's why the revision
is called 1815A, indicating it's a revision of the standard called 1815.
If we'd stuck with the MIL-STD thing, Ada 95 would have been 1815B. If
Ada 83 had been the first standard, it would simply have been 1815, and
Ada 80 would have been a draft version of 1815.

-- 
Jeff Carter
"My brain hurts!"
Monty Python's Flying Circus

Re: Unusual syntax

[Marin David Condic]

Ahhh The bureaucracy that comes with the military. :-) I really don't know
what sort of "Official" status Ada80 had - except that a) nobody built any
compilers to that standard (at least not any that got any sort of widespread
circulation) and b) my recollection of the intent was that it was never
supposed to serve as some sort of "final" standard by which people should be
guided in developing compilers. The intent was that it was to be reviewed,
commented on and eventually revised, so in a sense it was never a "real"
standard. Clearly, for paperwork purposes, it was given a number and maybe
in some bureaucratic sense it was therefore an "Official" standard - but for
practical purposes it wasn't used that way.

Still, its an interesting bit of history and I wish I still had a copy of
it. Sadly, it became compost somewhere along the line in a fit of making
space for more junk. :-)

MDC
--
Marin David Condic
Senior Software Engineer
Pace Micro Technology Americas    www.pacemicro.com
Enabling the digital revolution
e-Mail:    marin.condic@pacemicro.com


"Jeffrey Carter" <jrcarter@acm.org> wrote in message
news:3CE9B65A.BE66B61C@acm.org...
>
> I'm no expert, but I think 1815 was a standard. That's why the revision
> is called 1815A, indicating it's a revision of the standard called 1815.
> If we'd stuck with the MIL-STD thing, Ada 95 would have been 1815B. If
> Ada 83 had been the first standard, it would simply have been 1815, and
> Ada 80 would have been a draft version of 1815.
>

Re: Unusual syntax

[Mark Biggar]

Marin David Condic wrote:
> 
> Ahhh The bureaucracy that comes with the military. :-) I really don't know
> what sort of "Official" status Ada80 had - except that a) nobody built any
> compilers to that standard (at least not any that got any sort of widespread
> circulation) and b) my recollection of the intent was that it was never
> supposed to serve as some sort of "final" standard by which people should be
> guided in developing compilers. The intent was that it was to be reviewed,
> commented on and eventually revised, so in a sense it was never a "real"
> standard. Clearly, for paperwork purposes, it was given a number and maybe
> in some bureaucratic sense it was therefore an "Official" standard - but for
> practical purposes it wasn't used that way.

Some more history: The DOD let out 4 contracts for designing the
language that would later be called Ada.  The 4 language specs were
given the names Red, Blue, Yellow and Green and set out to a panel
of "Distinguished Reviewers" for comment.  The result of that was that
Red and Green were selected for further development.  Eventually
Green was chosen and named Ada.  This is why copies of the Ada 
standard are traditionally printed with green covers.  MIL-STD-1815 
or Ada80 was basically an unchanged version of the final Green spec.
After some more review and comment, a finalized version of the Ada
language spec was released as Ada83 or MIL-STD-1815A.

--
Mark Biggar
mark.a.biggar@attbi.com

Re: Unusual syntax

[Jeffrey Carter]

Mark Biggar wrote:
> 
> Some more history: The DOD let out 4 contracts for designing the
> language that would later be called Ada.  The 4 language specs were
> given the names Red, Blue, Yellow and Green and set out to a panel
> of "Distinguished Reviewers" for comment.  The result of that was that
> Red and Green were selected for further development.  Eventually
> Green was chosen and named Ada.

I heard Ichbiah say once that when the competitors were reduced to Red
and Green he knew he had won, because the US DOD would never accept a
red language.

-- 
Jeff Carter
"I blow my nose on you."
Monty Python & the Holy Grail

Re: Unusual syntax

[Marin David Condic]

And, of course, the Army paints everything green except their mules. :-)

MDC
--
Marin David Condic
Senior Software Engineer
Pace Micro Technology Americas    www.pacemicro.com
Enabling the digital revolution
e-Mail:    marin.condic@pacemicro.com


"Jeffrey Carter" <jrcarter@acm.org> wrote in message
news:3CEAF980.3A392277@acm.org...
>
> I heard Ichbiah say once that when the competitors were reduced to Red
> and Green he knew he had won, because the US DOD would never accept a
> red language.
>