Cannot use NULL as identifier?

Cannot use NULL as identifier?

[McDoobie]

I've written a small program that parses the contents of different
directories and searches for duplicate files.

I have an assignment that reads

FilePath : constant string := "tesfile.xxx" & ASCII.NULL;

Now, the GNAT compiler on Linux gives me the error 
"reserved word NULL cannot be used as identifier "

Now, I'm using the text_io and gnat.os_lib libraries to compile this, so
I'm assuming that os_lib makes an allowance for this. However, I could be
mistaken. I ripped the above code fragement from a website, and the
website (the Big Book of Linux Ada programming) doesnt appear to  indicate
that theres a problem with this. (Of course I probably overlooked
something.)

I'm also searching through "Programming in Ada95"(Barnes) trying to find
info on this error.

Any tips or pointers would be helpful.

Thanks.

McDoobie
Chris@dont.spam.me

Re: Cannot use NULL as identifier?

[Ted Dennison]

In article <Ad6R6.1259$DG1.337725@news1.rdc1.mi.home.com>, McDoobie says...
>
>FilePath : constant string := "tesfile.xxx" & ASCII.NULL;
>
>Now, the GNAT compiler on Linux gives me the error 
>"reserved word NULL cannot be used as identifier "

OK. There are 3 issues here:

1)  "null" is a keyword. It is used for "null" statements, and as a default
value for access objects. You can't create a variable with that name any more
than you can create a variable named "if".

2) The value you are looking for is "ASCII.NUL", not "ASCII.NULL". (A quick
check of the package specification would have told you this.

3) The package ASCII is obsolescent, so I wouldn't use it in new code if I were
you. You should be using "Ada.Characters.Latin_1.Nul".

---
T.E.D.    homepage   - http://www.telepath.com/dennison/Ted/TED.html
          home email - mailto:dennison@telepath.com

Re: Cannot use NULL as identifier?

[Philip Anderson]

McDoobie wrote:
> 
<snip> 
> FilePath : constant string := "tesfile.xxx" & ASCII.NULL;
> 
> Now, the GNAT compiler on Linux gives me the error
> "reserved word NULL cannot be used as identifier "
<snap>

ASCII.NUL; -- one 'L', because null is reserved.

Note that package ASCII is declared as obsolete in Ada 95.

-- 
hwyl/cheers,
Philip Anderson
Alenia Marconi Systems
Cwmbr�n, Cymru/Wales

Re: Cannot use NULL as identifier?

[Pascal Obry]

Philip Anderson <phil.anderson@amsjv.com> writes:
> Note that package ASCII is declared as obsolete in Ada 95.

It is obsolescent and not obsolete.

Pascal.

-- 

--|------------------------------------------------------
--| Pascal Obry                           Team-Ada Member
--| 45, rue Gabriel Peri - 78114 Magny Les Hameaux FRANCE
--|------------------------------------------------------
--|         http://perso.wanadoo.fr/pascal.obry
--|
--| "The best way to travel is by means of imagination"

Re: Cannot use NULL as identifier?

[Mats Karlssohn]

Pascal Obry wrote:
%<
> It is obsolescent and not obsolete.

What's the difference ? I'm sorry to say that this is one subtle part
of the english language that I havn't grasped yet. 

-- 
Mats Karlssohn, developer                         mailto:mats@mida.se  
Mida Systemutveckling AB                          http://www.mida.se
Box 64, S-732 22 ARBOGA, SWEDEN
Phone: +46-(0)589-89808   Fax: +46-(0)589-89809

Re: Cannot use NULL as identifier?

[David C. Hoos, Sr.]

"Obsolescent" means "becoming obsolete."
The "-cent" suffix is used on lots of words -- e.g.,
"nascent" means "being born,"  etc.

"Mats Karlssohn" <mats@mida.se> wrote in message
news:3B162FBD.B3CEE7DD@mida.se...
> Pascal Obry wrote:
> %<
> > It is obsolescent and not obsolete.
>
> What's the difference ? I'm sorry to say that this is one subtle part
> of the english language that I havn't grasped yet.
>
> --
> Mats Karlssohn, developer                         mailto:mats@mida.se
> Mida Systemutveckling AB                          http://www.mida.se
> Box 64, S-732 22 ARBOGA, SWEDEN
> Phone: +46-(0)589-89808   Fax: +46-(0)589-89809
>

Re: Cannot use NULL as identifier?

[Mats Karlssohn]

"David C. Hoos, Sr." wrote:
> 
> "Obsolescent" means "becoming obsolete."
> The "-cent" suffix is used on lots of words -- e.g.,
> "nascent" means "being born,"  etc.
> 
> "Mats Karlssohn" <mats@mida.se> wrote in message
> news:3B162FBD.B3CEE7DD@mida.se...
> > Pascal Obry wrote:
> > %<
> > > It is obsolescent and not obsolete.
> >
> > What's the difference ? I'm sorry to say that this is one subtle part
> > of the english language that I havn't grasped yet.

Ahh, thank you for enlighting me!


-- 
Mats Karlssohn, developer                         mailto:mats@mida.se  
Mida Systemutveckling AB                          http://www.mida.se
Box 64, S-732 22 ARBOGA, SWEDEN
Phone: +46-(0)589-89808   Fax: +46-(0)589-89809

Re: Cannot use NULL as identifier?

[Mario Amado Alves]

> "Obsolescent" means "becoming obsolete."
> . . .

Someone (Lackoff?) has proposed we understand well thru metaphors.  Hope
he's right.  Here's the biological one for the case at hand:

  obsolescent = old but not dead yet, perhaps immortal

  obsolete = dead

| |,| | | |RuaFranciscoTaborda24RcD 2815-249CharnecaCaparica 351+939354005
|M|A|R|I|O|
|A|M|A|D|O|DepartmentoDeInformaticaFCT/UNL 2825-114 Caparica 351+212958536
|A|L|V|E|S|                                                  fax 212948541
| | | | | |                 maa@di.fct.unl.pt                FCT 212948300

Re: Cannot use NULL as identifier?

[Florian Weimer]

"David C. Hoos, Sr." <david.c.hoos.sr@ada95.com> writes:

> "Obsolescent" means "becoming obsolete."
> The "-cent" suffix is used on lots of words -- e.g.,
> "nascent" means "being born,"  etc.

IIRC, it's the '-sc-' which indicates that a process is still in its
beginning, the '-ent' is a variation of the present participle suffix
in Latin.

Re: Cannot use NULL as identifier?

[Florian Weimer]

Philip Anderson <phil.anderson@amsjv.com> writes:

> ASCII.NUL; -- one 'L', because null is reserved.

Correct observation, wrong explanation.

The official character name according to ANSI X3.4-1986 is indeed
'NULL', but package ASCII uses the official abbreviations, and 'NULL'
becomes 'NUL'.

Re: Cannot use NULL as identifier?

[Martin Dowie]

ASCII is an obsolete package, use Ada.Characters.Latin_1 instead.
The other problem you have is 'NULL' with 2 'L' characters. So what
you need is:

  FilePath : constant string := "tesfile.xxx" & Ada.Characters.Latin_1.Nul;

Alternatively, it looks like you're trying to do things in a 'C'-way,
or interface with some 'C' routines, so have a look at Interfaces.C (and
maybe Interfaces.C.Strings) to find routines to create nul-terminated
strings.

Enjoy!

McDoobie <someone@nospam.net> wrote in message
news:Ad6R6.1259$DG1.337725@news1.rdc1.mi.home.com...
> I've written a small program that parses the contents of different
> directories and searches for duplicate files.
>
> I have an assignment that reads
>
> FilePath : constant string := "tesfile.xxx" & ASCII.NULL;
>
> Now, the GNAT compiler on Linux gives me the error
> "reserved word NULL cannot be used as identifier "
>
> Now, I'm using the text_io and gnat.os_lib libraries to compile this, so
> I'm assuming that os_lib makes an allowance for this. However, I could be
> mistaken. I ripped the above code fragement from a website, and the
> website (the Big Book of Linux Ada programming) doesnt appear to  indicate
> that theres a problem with this. (Of course I probably overlooked
> something.)
>
> I'm also searching through "Programming in Ada95"(Barnes) trying to find
> info on this error.
>
> Any tips or pointers would be helpful.
>
> Thanks.
>
> McDoobie
> Chris@dont.spam.me

Re: Cannot use NULL as identifier?

[Petter Fryklund]

This is perhaps not the best and most efficient solution, but it works:

with Ada.Characters.Latin_1;
...
...
FilePath : constant string := "tesfile.xxx" & Ada.Characters.Latin_1.Nul;

McDoobie wrote in message ...
>I've written a small program that parses the contents of different
>directories and searches for duplicate files.
>
>I have an assignment that reads
>
>FilePath : constant string := "tesfile.xxx" & ASCII.NULL;
>
>Now, the GNAT compiler on Linux gives me the error
>"reserved word NULL cannot be used as identifier "
>
>Now, I'm using the text_io and gnat.os_lib libraries to compile this, so
>I'm assuming that os_lib makes an allowance for this. However, I could be
>mistaken. I ripped the above code fragement from a website, and the
>website (the Big Book of Linux Ada programming) doesnt appear to  indicate
>that theres a problem with this. (Of course I probably overlooked
>something.)
>
>I'm also searching through "Programming in Ada95"(Barnes) trying to find
>info on this error.
>
>Any tips or pointers would be helpful.
>
>Thanks.
>
>McDoobie
>Chris@dont.spam.me

Re: Cannot use NULL as identifier?

[Randy Brukardt]

McDoobie wrote in message ...
>I've written a small program that parses the contents of different
>directories and searches for duplicate files.
>
>I have an assignment that reads
>
>FilePath : constant string := "tesfile.xxx" & ASCII.NULL;


Hopefully, someone has pointed out by now that the name of the charactar
is "NUL", not "null"! (My ISP's news server went out, so I missed some
messages...). So the above should say "Ascii.Nul".

            Randy.

Re: Cannot use NULL as identifier?

[Marin David Condic]

Null is a reserved word in Ada - used as a null statement and as a value for
access types, etc. You can't use it as an identifier.

What you probably want is ASCII.Nul - notice only one 'l'.

Also, unless you are interfacing to some C/C++ routines, you do not need to
terminate strings with Nul. You are much better off using the attributes
'First, 'Last, 'Range, etc. along with the string handling routines you'll
find in Ada.Strings, Ada.Strings.Fixed, Ada.Strings.Bounded,
Ada.Strings.Unbounded. (My personal favorite is to use Ada.Strings.Unbounded
for just about everything. It will have some speed/space penalties over
fixed strings, but you'd really have to have an intense application to start
noticing the difference.)

BTW, you probably don't want to use the package ASCII since it is falling
out of vogue and may eventually go away. More appropriately, you should use
Ada.Characters.Latin_1 which also contains a constant called "Nul".

If you have not done so already, you will want to get hold of an Ada95
Reference Manual (plenty of electronic sources). To really get all the
benefits of Ada, you'll want to look over all the appendices and at least be
cognizant of the language defined packages and what they contain. That way,
when you need a resource (like character constants, math routines, string
manipulation, etc.) you'll at least have a vague memory of what is available
and know where to look for more help. I repeatedly find myself in there
digging up routines to leverage someone else's work! :-)

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


"McDoobie" <someone@nospam.net> wrote in message
news:Ad6R6.1259$DG1.337725@news1.rdc1.mi.home.com...
> I've written a small program that parses the contents of different
> directories and searches for duplicate files.
>
> I have an assignment that reads
>
> FilePath : constant string := "tesfile.xxx" & ASCII.NULL;
>
> Now, the GNAT compiler on Linux gives me the error
> "reserved word NULL cannot be used as identifier "
>
> Now, I'm using the text_io and gnat.os_lib libraries to compile this, so
> I'm assuming that os_lib makes an allowance for this. However, I could be
> mistaken. I ripped the above code fragement from a website, and the
> website (the Big Book of Linux Ada programming) doesnt appear to  indicate
> that theres a problem with this. (Of course I probably overlooked
> something.)
>
> I'm also searching through "Programming in Ada95"(Barnes) trying to find
> info on this error.
>
> Any tips or pointers would be helpful.
>
> Thanks.
>
> McDoobie
> Chris@dont.spam.me

Re: Cannot use NULL as identifier?

[Robert A Duff]

"Marin David Condic" <marin.condic.auntie.spam@pacemicro.com> writes:

> BTW, you probably don't want to use the package ASCII since it is falling
> out of vogue and may eventually go away.

The obsolescent features, including package ASCII, will never go away.

- Bob

Re: Cannot use NULL as identifier?

[McDoobie]

In article <9f2tuk$hbg$1@nh.pace.co.uk>, "Marin David Condic"
<marin.condic.auntie.spam@pacemicro.com> wrote:

> Null is a reserved word in Ada - used as a null statement and as a value
> for access types, etc. You can't use it as an identifier.
> 
> What you probably want is ASCII.Nul - notice only one 'l'.
> 
> Also, unless you are interfacing to some C/C++ routines, you do not need
> to terminate strings with Nul. You are much better off using the
> attributes
> 'First, 'Last, 'Range, etc. along with the string handling routines
> you'll
> find in Ada.Strings, Ada.Strings.Fixed, Ada.Strings.Bounded,
> Ada.Strings.Unbounded. (My personal favorite is to use
> Ada.Strings.Unbounded for just about everything. It will have some
> speed/space penalties over fixed strings, but you'd really have to have
> an intense application to start noticing the difference.)
> 
> BTW, you probably don't want to use the package ASCII since it is
> falling out of vogue and may eventually go away. More appropriately, you
> should use Ada.Characters.Latin_1 which also contains a constant called
> "Nul".
> 
> If you have not done so already, you will want to get hold of an Ada95
> Reference Manual (plenty of electronic sources). To really get all the
> benefits of Ada, you'll want to look over all the appendices and at
> least be cognizant of the language defined packages and what they
> contain. That way, when you need a resource (like character constants,
> math routines, string manipulation, etc.) you'll at least have a vague
> memory of what is available and know where to look for more help. I
> repeatedly find myself in there digging up routines to leverage someone
> else's work! :-)
> 
> MDC
> --
> Marin David Condic Senior Software Engineer Pace Micro Technology
> Americas    www.pacemicro.com Enabling the digital revolution e-Mail:   
> marin.condic@pacemicro.com Web:      http://www.mcondic.com/
> 

Thanks for your reply. I have duly noted the difference between 'NUL' and 
'NULL' thanks to the many replies pointing out that goof up. Also, I will be 
spending some time exploring the Latin_1 package in detail, as well as 
exploring the internals of the Ada system much more thoroughly.
I've recently purchased an Ada textbook, so I should proceed much more 
rapidly now.

And yes, I was interfacing with the GNU glibc libraries. glibc 2.2 to be exact.

I wonder if it would make more sense to just put all my glibc interfaces 
into an Ada package and then use them that way. However, I'm also
aware that there are Posix bindings already available, and so I'm tempted to
say that it would make more sense to use those instead. However, as I am 
relatively inexperienced in the whole OOP paradigm (coming from a C and 
x86 ASM background) I cant yet say for sure what the best route would be.

Back to the books I guess. ;->

Thanks again for all the replies.

McDoobie
chris@dont.spam.me

Re: Cannot use NULL as identifier?

[Marin David Condic]

If you're looking for books, try: http://www.adapower.com/ You will also
find an on-line Ada Reference manual there. If you are using Gnat on a PC
and have AdaGIDE installed, you should have access to an ARM through the
"Help" menu item. The ARM is an *indispensible* tool for Ada developers
because it will give you the precise meaning of all language features and
complete documentation of all useful packages that are guaranteed (mostly -
some appendices are optional, but quite commonly implemented) to be part of
the language.

For OOP in Ada, I rather liked the book "Object Oriented Software In Ada95"
by Michael A. Smith. However, there are a number of other books on the
subject, so you'll get a variety of recommendations. Almost anything would
help you to shift gears from a C/Assembler mode of thought to an Ada/OOP
mode of thought, so you need not be too picky.

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


"McDoobie" <someone@nospam.net> wrote in message
news:RkpR6.5080$DG1.1143031@news1.rdc1.mi.home.com...
>
> Thanks for your reply. I have duly noted the difference between 'NUL' and
> 'NULL' thanks to the many replies pointing out that goof up. Also, I will
be
> spending some time exploring the Latin_1 package in detail, as well as
> exploring the internals of the Ada system much more thoroughly.
> I've recently purchased an Ada textbook, so I should proceed much more
> rapidly now.
>
> And yes, I was interfacing with the GNU glibc libraries. glibc 2.2 to be
exact.
>
> I wonder if it would make more sense to just put all my glibc interfaces
> into an Ada package and then use them that way. However, I'm also
> aware that there are Posix bindings already available, and so I'm tempted
to
> say that it would make more sense to use those instead. However, as I am
> relatively inexperienced in the whole OOP paradigm (coming from a C and
> x86 ASM background) I cant yet say for sure what the best route would be.
>
> Back to the books I guess. ;->
>
> Thanks again for all the replies.
>
> McDoobie
> chris@dont.spam.me

Re: Cannot use NULL as identifier?

[John English]

Marin David Condic wrote:
> For OOP in Ada, I rather liked the book "Object Oriented Software In Ada95"
> by Michael A. Smith. However, there are a number of other books on the
> subject...

Not any more; as far as publishers are concerned, OOP means "out of
print" when applied to Ada :-(

Mike's book is now OOP, as is mine. We are now having to consider
teaching another language at Brighton because of the lack of suitable
textbooks for beginners. The publishers aren't interested because the
market's too small. And various sections of industry are complaining
that they can't find enough trained Ada developers, so they're being
forced to move to Java or C++.

Sigh.

-----------------------------------------------------------------
 John English              | mailto:je@brighton.ac.uk
 Senior Lecturer           | http://www.comp.it.bton.ac.uk/je
 Dept. of Computing        | ** NON-PROFIT CD FOR CS STUDENTS **
 University of Brighton    |    -- see http://burks.bton.ac.uk
-----------------------------------------------------------------

Re: Cannot use NULL as identifier?

[Ted Dennison]

In article <3B17A028.A4A91C3F@brighton.ac.uk>, John English says...
>
>Mike's book is now OOP, as is mine. We are now having to consider
>teaching another language at Brighton because of the lack of suitable
>textbooks for beginners. The publishers aren't interested because the
>market's too small. And various sections of industry are complaining
>that they can't find enough trained Ada developers, so they're being
>forced to move to Java or C++.

Well, all we have to do now is wait for 75 years after you die, and we can just
release it on the web for anyone to read or print out. :-)

Yet another illustration of why the copyright period is *far* too long.

---
T.E.D.    homepage   - http://www.telepath.com/dennison/Ted/TED.html
          home email - mailto:dennison@telepath.com

Re: Cannot use NULL as identifier?

[John English]

Ted Dennison wrote:
> 
> In article <3B17A028.A4A91C3F@brighton.ac.uk>, John English says...
> >
> >Mike's book is now OOP, as is mine. We are now having to consider
> >teaching another language at Brighton because of the lack of suitable
> >textbooks for beginners. The publishers aren't interested because the
> >market's too small. And various sections of industry are complaining
> >that they can't find enough trained Ada developers, so they're being
> >forced to move to Java or C++.
> 
> Well, all we have to do now is wait for 75 years after you die, and we can just
> release it on the web for anyone to read or print out. :-)
> 
> Yet another illustration of why the copyright period is *far* too long.

Don't worry, I'm getting the copyright back and plan to release my
book online in the near future...

-----------------------------------------------------------------
 John English              | mailto:je@brighton.ac.uk
 Senior Lecturer           | http://www.comp.it.bton.ac.uk/je
 Dept. of Computing        | ** NON-PROFIT CD FOR CS STUDENTS **
 University of Brighton    |    -- see http://burks.bton.ac.uk
-----------------------------------------------------------------

Re: Cannot use NULL as identifier?

[Simon Wright]

John English <je@brighton.ac.uk> writes:

> Don't worry, I'm getting the copyright back and plan to release my
> book online in the near future...

That's really good news, good luck!

Re: Cannot use NULL as identifier?

[Gary Scott]

John English wrote:
> 
> Marin David Condic wrote:
> > For OOP in Ada, I rather liked the book "Object Oriented Software In Ada95"
> > by Michael A. Smith. However, there are a number of other books on the
> > subject...
> 
> Not any more; as far as publishers are concerned, OOP means "out of
> print" when applied to Ada :-(
> 
> Mike's book is now OOP, as is mine. We are now having to consider
> teaching another language at Brighton because of the lack of suitable
> textbooks for beginners. The publishers aren't interested because the
> market's too small. And various sections of industry are complaining
> that they can't find enough trained Ada developers, so they're being
> forced to move to Java or C++.

Another one of those red harrings.  Most of our products were/are
programmed in Jovial.  Try finding a trained Jovial employee on the open
market.

> 
> Sigh.
> 
> -----------------------------------------------------------------
>  John English              | mailto:je@brighton.ac.uk
>  Senior Lecturer           | http://www.comp.it.bton.ac.uk/je
>  Dept. of Computing        | ** NON-PROFIT CD FOR CS STUDENTS **
>  University of Brighton    |    -- see http://burks.bton.ac.uk
> -----------------------------------------------------------------

Re: Cannot use NULL as identifier?

[Marin David Condic]

I would agree. As a trained Jovial programmer myself, I recall that the way
I learned it was that I took a new job, someone dumped a manual & some code
on me and I got busy. Getting the rudiments of a language down enough to
write useful code or understand someone else's code just doesn't take long -
even for a language as big & rich as Ada. Obviously, if you want to use the
full richness of a language, that may take longer before you become fully
proficient. But a project may only need a handful of people intimately
familiar & conversant in Ada to handle architectural issues. Everyone else
can be brought on board & learn it as they go.

At one point in time, C++, Java, Eiffel, Python, etc. did not exist.
Somehow, people managed to find programmers with 5 years of experience in
all of these languages days after the first compilers were released (tongue
firmly in cheek) so it must be possible to take programmers unfamiliar with
a language and get them up to speed quickly & efficiently enough to be cost
effective - or there would never be an ability to get *any* new language
accepted.

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


"Gary Scott" <Gary.L.Scott@lmtas.lmco.com> wrote in message
news:3B17AEA6.39A75C35@lmtas.lmco.com...
> Another one of those red harrings.  Most of our products were/are
> programmed in Jovial.  Try finding a trained Jovial employee on the open
> market.
>

Re: Cannot use NULL as identifier?

[Marin David Condic]

O.K. We're in the age of the Internet and electronic zeros and ones sort of
publishing, right? I now have dozens of manuals for a system I'm working
with that were all published in .PDF form & it works pretty well. Why not
put the book(s) on a web page somewhere in some reasonably common format and
make them generally available to students, professors, curious general
public, etc? If someone feels the need to have a hard copy, they can run it
out on their printer and do their own tree-killing. I think it would help
promote Ada and would probably help make the author a bit more well known
around the world, etc. Not much money in college textbooks anyway.

Just a thought...

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


"John English" <je@brighton.ac.uk> wrote in message
news:3B17A028.A4A91C3F@brighton.ac.uk...
> Not any more; as far as publishers are concerned, OOP means "out of
> print" when applied to Ada :-(
>
> Mike's book is now OOP, as is mine. We are now having to consider
> teaching another language at Brighton because of the lack of suitable
> textbooks for beginners. The publishers aren't interested because the
> market's too small. And various sections of industry are complaining
> that they can't find enough trained Ada developers, so they're being
> forced to move to Java or C++.
>
> Sigh.
>
> -----------------------------------------------------------------
>  John English              | mailto:je@brighton.ac.uk
>  Senior Lecturer           | http://www.comp.it.bton.ac.uk/je
>  Dept. of Computing        | ** NON-PROFIT CD FOR CS STUDENTS **
>  University of Brighton    |    -- see http://burks.bton.ac.uk
> -----------------------------------------------------------------

Re: Cannot use NULL as identifier?

[Brian Rogoff]

On Fri, 1 Jun 2001, John English wrote:
> Marin David Condic wrote:
> > For OOP in Ada, I rather liked the book "Object Oriented Software In Ada95"
> > by Michael A. Smith. However, there are a number of other books on the
> > subject...
> 
> Not any more; as far as publishers are concerned, OOP means "out of
> print" when applied to Ada :-(
> 
> Mike's book is now OOP, as is mine. 

Any luck on getting back the rights so that you can web it? 

That's really unfortunate, since yours is the book I'd have recommended
for the beginner, even though I'm more in the anti-OOP camp. 

-- Brian

Re: Cannot use NULL as identifier?

[David Gillon]

John English wrote:

> as far as publishers are concerned, OOP means "out of
> print" when applied to Ada :-(
> 
> Mike's book is now OOP, as is mine. We are now having to consider
> teaching another language at Brighton because of the lack of suitable
> textbooks for beginners. 
[snip]
> Sigh.

Sigh indeed.

If the rights have reverted with your book going out of print then you
could always try what the Operational Research department at Lancaster
did (and may still do) -- they had the complete course notes written up
for sale in unbound form and the students were expected to buy them. I
don't suppose they turned a great deal of profit on the deal after
deducting reproduction costs, but it did mean there was a 'textbook'
available that precisely fitted the course content, and no danger of it
going out of print.

-- 


David Gillon

Re: Cannot use NULL as identifier?

[Stephen Leake]

John English <je@brighton.ac.uk> writes:

> Marin David Condic wrote:
> > For OOP in Ada, I rather liked the book "Object Oriented Software In Ada95"
> > by Michael A. Smith. However, there are a number of other books on the
> > subject...
> 
> Not any more; as far as publishers are concerned, OOP means "out of
> print" when applied to Ada :-(
> 
> Mike's book is now OOP, as is mine. We are now having to consider
> teaching another language at Brighton because of the lack of suitable
> textbooks for beginners. The publishers aren't interested because the
> market's too small. And various sections of industry are complaining
> that they can't find enough trained Ada developers, so they're being
> forced to move to Java or C++.

Just going out on a limb here - 

Are paper textbooks really still necessary? Wouldn't a PDF file
downloaded to the student's computer serve? 

It seems to me anyone taking an Ada course will have good access to a
computer capable of displaying PDF files. I know I _much_ prefer
online documentation to paper books!

-- 
-- Stephe

Re: Cannot use NULL as identifier?

[tmoran]

> I know I _much_ prefer online documentation to paper books!
  Arghhh!  Let me cast a STRONG vote for bound paper.  Easy on the
eyes, highly portable, easily loaned for a day or a week, simple
to spot on the bookshelves even when all you remember is
"thick with a black spine", usually half the paper of a computer
printout, and generally cheap/page.

Re: Cannot use NULL as identifier?

[Marin David Condic]

I'm with you WRT the desirability of paper in many circumstances. Books made
of paper are a lot easier to read out at the beach with a homebrew in close
grasp. Large printed documents are sometimes easier to leaf through rapidly,
dog-ear, post-it, gloss, etc., than their electronic counterparts. They will
probably always have advantages - not the least of which is they make good
compost when the subject at hand is no longer important.

That said, I'd still rather see a few generally available Ada texts
(beginning..advanced) in PDF or HTML (with .ZIP versions for download) stuck
out on web pages with little or no restriction in use, than to have
expensive, hard to get, out-of-print paper versions as the only source for
material. Better for everyone if material a publisher doesn't want anymore
ends up on a web page where students & the general public can get at it
and - if desired - slaughter a few trees to print it out. PDF is better than
no books at all - and it has its advantages as well.

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


<tmoran@acm.org> wrote in message
news:uXPS6.61856$%i7.47594830@news1.rdc1.sfba.home.com...
> > I know I _much_ prefer online documentation to paper books!
>   Arghhh!  Let me cast a STRONG vote for bound paper.  Easy on the
> eyes, highly portable, easily loaned for a day or a week, simple
> to spot on the bookshelves even when all you remember is
> "thick with a black spine", usually half the paper of a computer
> printout, and generally cheap/page.

Paper or Plastic?

[Ted Dennison]

In article <9fglbb$a06$1@nh.pace.co.uk>, Marin David Condic says...
>
>That said, I'd still rather see a few generally available Ada texts
>(beginning..advanced) in PDF or HTML (with .ZIP versions for download) stuck
>out on web pages with little or no restriction in use, than to have
>expensive, hard to get, out-of-print paper versions as the only source for
>material. Better for everyone if material a publisher doesn't want anymore
>ends up on a web page where students & the general public can get at it
>and - if desired - slaughter a few trees to print it out. PDF is better than
>no books at all - and it has its advantages as well.

More to the point, I think it would help Ada out immensly as well. Whenever I
need to learn a new language or complicated tool, I always do a web search for
online learning guides. It would be really nice to have such a guide available
for Ada. 

Plus if the online version becomes widely used, it might even reignite interest
in the dead-tree edition...

---
T.E.D.    homepage   - http://www.telepath.com/dennison/Ted/TED.html
          home email - mailto:dennison@telepath.com

Re: Cannot use NULL as identifier?

[Mats Karlssohn]

Stephen Leake wrote:
%<
> Just going out on a limb here -
> 
> Are paper textbooks really still necessary? Wouldn't a PDF file
> downloaded to the student's computer serve?
> 
> It seems to me anyone taking an Ada course will have good access to a
> computer capable of displaying PDF files. I know I _much_ prefer
> online documentation to paper books!

I'd say: "YES they are!"

I tend to do alot of my "study type" reading in in bed (or laying on
the carpet), and holding a screen is a bit heavvy :) As for reference
documents the opposite is true, I (almost) only use them in front of
the computer and I probably want to do rbitrary searches in them, so
a hypertex version is preferable (but a .pdf is better than nothing).

I'd sure love the "Ada quality and style" as HTML documents...

-- 
Mats Karlssohn, developer                         mailto:mats@mida.se  
Mida Systemutveckling AB                          http://www.mida.se
Box 64, S-732 22 ARBOGA, SWEDEN
Phone: +46-(0)589-89808   Fax: +46-(0)589-89809

Re: Cannot use NULL as identifier?

[John English]

Mats Karlssohn wrote:
> I'd sure love the "Ada quality and style" as HTML documents...

It's available.

<plug>
For even more convenience, have a look at BURKS, a low-cost set
of 3 CDs (online at http://burks.bton.ac.uk/) with an Ada section
which includes the LRM, Rationale, and Q&S, so you don't even need
to be online to be able to read it...
</plug>

-----------------------------------------------------------------
 John English              | mailto:je@brighton.ac.uk
 Senior Lecturer           | http://www.comp.it.bton.ac.uk/je
 Dept. of Computing        | ** NON-PROFIT CD FOR CS STUDENTS **
 University of Brighton    |    -- see http://burks.bton.ac.uk
-----------------------------------------------------------------

Re: Cannot use NULL as identifier?

[David C. Hoos, Sr.]

The "Ada quality and style" is available as HTML documents at
http://www.adaic.org/docs/style-guide/95style/html/cover.html

"Mats Karlssohn" <mats@mida.se> wrote in message
news:3B1DF7C5.A86CD69A@mida.se...
<snip>
> I'd sure love the "Ada quality and style" as HTML documents...
>
> --
> Mats Karlssohn, developer                         mailto:mats@mida.se
> Mida Systemutveckling AB                          http://www.mida.se
> Box 64, S-732 22 ARBOGA, SWEDEN
> Phone: +46-(0)589-89808   Fax: +46-(0)589-89809



-----= Posted via Newsfeeds.Com, Uncensored Usenet News =-----
http://www.newsfeeds.com - The #1 Newsgroup Service in the World!
-----==  Over 80,000 Newsgroups - 16 Different Servers! =-----

Re: Cannot use NULL as identifier?

[Mats Karlssohn]

"David C. Hoos, Sr." wrote:
> 
> The "Ada quality and style" is available as HTML documents at
> http://www.adaic.org/docs/style-guide/95style/html/cover.html
> 
> "Mats Karlssohn" <mats@mida.se> wrote in message
> news:3B1DF7C5.A86CD69A@mida.se...
> <snip>
> > I'd sure love the "Ada quality and style" as HTML documents...

Werrrry nice! I had no idea! Thanks!

-- 
Mats Karlssohn, developer                         mailto:mats@mida.se  
Mida Systemutveckling AB                          http://www.mida.se
Box 64, S-732 22 ARBOGA, SWEDEN
Phone: +46-(0)589-89808   Fax: +46-(0)589-89809

Re: Cannot use NULL as identifier?

[Tarjei T. Jensen]

John English wrote
>Mike's book is now OOP, as is mine. We are now having to consider
>teaching another language at Brighton because of the lack of suitable
>textbooks for beginners. The publishers aren't interested because the
>market's too small. And various sections of industry are complaining
>that they can't find enough trained Ada developers, so they're being
>forced to move to Java or C++.

Print on demand publishing is something that is coming. This means that you
print just as many books you need when you need them. This should be
practical for those who want to publish their own books.

Publishing on the web might not be the best idea. It will strain printer
resources on the universities involved. It could perhaps be better to print
your own unbound books. Perhaps it would be cheaper? Perhaps one would
produce smaller, to the point volumes? Perhaps there could be cooperation
between universities to get a discount on printing?

If one uses a standardized environment (e.g. LaTeX) to produce the book, one
should be able to have some synergy with other authors. e.g. with regards to
formatting of code, conversion to pdf, etc.

Perhaps a new publisher would be in order? E.g. Chartwell-Bratt
(?)/studentlitteratur which produces low priced books.


Greetings,

Web Publishing was RE: Cannot use NULL as identifier?

[Robert C. Leif, Ph.D.]

From: Bob Leif
To: Tarjei T. Jensen et al.

There is one ubiquitous standardized environment, Adobe PDF. Another
possible choice is archive, single file (*.mht). Has anyone implemented
either of these formats in Ada?

Disintermediating the publishers (authors selling directly to the customers)
would have two significant benefits: 1) increasing the authors' income, and
2) decreasing the cost to the reader.

-----Original Message-----
From: comp.lang.ada-admin@ada.eu.org
[mailto:comp.lang.ada-admin@ada.eu.org]On Behalf Of Tarjei T. Jensen
Sent: Tuesday, June 05, 2001 1:38 AM
To: comp.lang.ada@ada.eu.org
Subject: Re: Cannot use NULL as identifier?



John English wrote
>Mike's book is now OOP, as is mine. We are now having to consider
>teaching another language at Brighton because of the lack of suitable
>textbooks for beginners. The publishers aren't interested because the
>market's too small. And various sections of industry are complaining
>that they can't find enough trained Ada developers, so they're being
>forced to move to Java or C++.

Print on demand publishing is something that is coming. This means that you
print just as many books you need when you need them. This should be
practical for those who want to publish their own books.

Publishing on the web might not be the best idea. It will strain printer
resources on the universities involved. It could perhaps be better to print
your own unbound books. Perhaps it would be cheaper? Perhaps one would
produce smaller, to the point volumes? Perhaps there could be cooperation
between universities to get a discount on printing?

If one uses a standardized environment (e.g. LaTeX) to produce the book, one
should be able to have some synergy with other authors. e.g. with regards to
formatting of code, conversion to pdf, etc.

Perhaps a new publisher would be in order? E.g. Chartwell-Bratt
(?)/studentlitteratur which produces low priced books.


Greetings,

Re: Web Publishing was RE: Cannot use NULL as identifier?

[Tarjei T. Jensen]

Robert C. Leif, Ph.D. :
>There is one ubiquitous standardized environment, Adobe PDF. Another
>possible choice is archive, single file (*.mht). Has anyone implemented
>either of these formats in Ada?

I doubt that they have been done in Ada, but a number of tools are available
nevertheless (probably written in C). I was more concerned with establishing
a quality tool chain than creating any of these tools in ada.


Greetings,

Re: Cannot use NULL as identifier?

[Claude SIMON]

May be ASCII.NUL is best than ASCII.NULL

McDoobie a �crit :

> I've written a small program that parses the contents of different
> directories and searches for duplicate files.
>
> I have an assignment that reads
>
> FilePath : constant string := "tesfile.xxx" & ASCII.NULL;
>
> Now, the GNAT compiler on Linux gives me the error
> "reserved word NULL cannot be used as identifier "
>
> Now, I'm using the text_io and gnat.os_lib libraries to compile this, so
> I'm assuming that os_lib makes an allowance for this. However, I could be
> mistaken. I ripped the above code fragement from a website, and the
> website (the Big Book of Linux Ada programming) doesnt appear to  indicate
> that theres a problem with this. (Of course I probably overlooked
> something.)
>
> I'm also searching through "Programming in Ada95"(Barnes) trying to find
> info on this error.
>
> Any tips or pointers would be helpful.
>
> Thanks.
>
> McDoobie
> Chris@dont.spam.me

RE: Cannot use NULL as identifier?

[Beard, Frank]

-----Original Message-----
From: Ted Dennison [mailto:dennison@telepath.com]

> 3) The package ASCII is obsolescent, so I wouldn't use
> it in new code if I were you. You should be using
> "Ada.Characters.Latin_1.Nul".

As Ben Brosgol pointed out, ASCII was obsolescent before
the ASCII standard was expanded to include characters 128
through 255.  So, the odds of ASCII becoming obsolete are
slim to none.  So, I wouldn't worry too much about whether
or not to use ASCII.

Even if it does become obsolete, it is a relatively
simply global substitute to replace "ASCII" with 
"Ada.Characters.Latin_1.Nul", or do a library level rename.
Besides "Ada.Characters.Latin_1.Nul" being ugly to look at,
if for nothing else, I will continue to use ASCII to avoid
the lame analogies of Latin to Ada made by some of the C++
hacks ("A dead language for a dead language").

Frank

Re: Cannot use NULL as identifier?

[John English]

"Beard, Frank" wrote:
> Even if [ASCII] does become obsolete, it is a relatively
> simply global substitute to replace "ASCII" with
> "Ada.Characters.Latin_1.Nul", or do a library level rename.

You'd also have to put "with ASCII" in front of the relevant units,
since it would then be a normal package rather than part of Standard.

-----------------------------------------------------------------
 John English              | mailto:je@brighton.ac.uk
 Senior Lecturer           | http://www.comp.it.bton.ac.uk/je
 Dept. of Computing        | ** NON-PROFIT CD FOR CS STUDENTS **
 University of Brighton    |    -- see http://burks.bton.ac.uk
-----------------------------------------------------------------

Re: Cannot use NULL as identifier?

[Florian Weimer]

"Beard, Frank" <beardf@spawar.navy.mil> writes:

> As Ben Brosgol pointed out, ASCII was obsolescent before
> the ASCII standard was expanded to include characters 128
> through 255.

Well, I think I've got a current copy of the ASCII standard, and it
defines only 128 characters...

RE: Cannot use NULL as identifier?

[Beard, Frank]

Well, I saw it referenced somewhere, and Ben
confirmed it.  I think it was the same reason
type Character was expanded from 128 to 256.

In any event, the first 128 characters are 
never going to change.  So, worse case, I'll
cut and paste the current ASCII package and
paste it into my own "My_ASCII" package and
do a library level rename.  It will probably
have all the character constants I will ever
need.  Or I could be lazy and make ASCII
rename Latin_1.

And, if I turns out that I am wrong, then in
twenty years, when it finally goes away, I'll
admit you're right.  :-)

Frank

-----Original Message-----
From: Florian Weimer [mailto:fw@deneb.enyo.de]
Sent: Saturday, June 02, 2001 6:54 AM
To: comp.lang.ada@ada.eu.org
Subject: Re: Cannot use NULL as identifier?


"Beard, Frank" <beardf@spawar.navy.mil> writes:

> As Ben Brosgol pointed out, ASCII was obsolescent before
> the ASCII standard was expanded to include characters 128
> through 255.

Well, I think I've got a current copy of the ASCII standard, and it
defines only 128 characters...
_______________________________________________
comp.lang.ada mailing list
comp.lang.ada@ada.eu.org
http://ada.eu.org/mailman/listinfo/comp.lang.ada

Re: Cannot use NULL as identifier?

[Robert A Duff]

"Beard, Frank" <beardf@spawar.navy.mil> writes:

> Well, I saw it referenced somewhere, and Ben
> confirmed it.  I think it was the same reason
> type Character was expanded from 128 to 256.

Not sure what "it" Ben confirmed...

> In any event, the first 128 characters are 
> never going to change.  So, worse case, I'll
> cut and paste the current ASCII package and
> paste it into my own "My_ASCII" package and
> do a library level rename.  It will probably
> have all the character constants I will ever
> need.  Or I could be lazy and make ASCII
> rename Latin_1.

It is illegal to have a library unit called ASCII.
(And I'll bet you it will always be illegal.)

> And, if I turns out that I am wrong, then in
> twenty years, when it finally goes away, I'll
> admit you're right.  :-)

Package ASCII will never go away, so long as there is an Ada standard.

- Bob

RE: Cannot use NULL as identifier?

[Beard, Frank]

-----Original Message-----
From: Robert A Duff [mailto:bobduff@world.std.com]

"Beard, Frank" <beardf@spawar.navy.mil> writes:

>> Well, I saw it referenced somewhere, and Ben
>> confirmed it.  I think it was the same reason
>> type Character was expanded from 128 to 256.
>
>Not sure what "it" Ben confirmed...

The extension of ASCII from 128 to 256 characters.

>> In any event, the first 128 characters are 
>> never going to change.  So, worse case, I'll
>> cut and paste the current ASCII package and
>> paste it into my own "My_ASCII" package and
>> do a library level rename.  It will probably
>> have all the character constants I will ever
>> need.  Or I could be lazy and make ASCII
>> rename Latin_1.
>
>It is illegal to have a library unit called ASCII.
>(And I'll bet you it will always be illegal.)

Seems like something would have happened by now
if this were true.

>> And, if I turns out that I am wrong, then in
>> twenty years, when it finally goes away, I'll
>> admit you're right.  :-)
>
>Package ASCII will never go away, so long as there
>is an Ada standard.

I agree with you.  I don't think it will ever go
away either, but the LRM did indicate that it 
probably would.

So, I think everyone's concerns were valid.
And if you don't mind using the
Ada.Characters.Latin_1, more power to you.

Frank

Re: Cannot use NULL as identifier?

[Robert A Duff]

"Beard, Frank" <beardf@spawar.navy.mil> writes:

> >It is illegal to have a library unit called ASCII.
> >(And I'll bet you it will always be illegal.)
> 
> Seems like something would have happened by now
> if this were true.

Heh?

> I agree with you.  I don't think it will ever go
> away either, but the LRM did indicate that it 
> probably would.

The RM says it's "obsolescent".  It doesn't say it's going away.

- Bob

RE: Cannot use NULL as identifier?

[Beard, Frank]

-----Original Message-----
From: Robert A Duff [mailto:bobduff@world.std.com]

>> I agree with you.  I don't think it will ever go
>> away either, but the LRM did indicate that it 
>> probably would.
>
> The RM says it's "obsolescent".  It doesn't say it's going away.

To quote my American Heritage Dictionary:

   obsolescent - In the process of passing out of use;
                 becoming obsolete.

   obsolete - No longer in use.

So it sounds to me like "obsolescent" means at some point
it will no longer be used, just not yet.

Frank

Re: Cannot use NULL as identifier?

[Tucker Taft]

"Beard, Frank" wrote:
> 
> -----Original Message-----
> From: Robert A Duff [mailto:bobduff@world.std.com]
> ...
> > The RM says it's "obsolescent".  It doesn't say it's going away.
> 
> To quote my American Heritage Dictionary:
> 
>    obsolescent - In the process of passing out of use;
>                  becoming obsolete.
> 
>    obsolete - No longer in use.
> 
> So it sounds to me like "obsolescent" means at some point
> it will no longer be used, just not yet.

Our real reason for moving things into the "obsolescent"
annex was to eliminate features from the "main" part of the
manual that were clearly redundant with other features.
New users of Ada need know nothing about the obsolescent
features.  They may stay in the language forever for
compatibility reasons, but there is no other reason that
we believe they are needed, and we wouldn't expect new
code to use them.

So they are going away in the sense that less and less
Ada code will use the features.  They may be supported
by compilers, and perhaps even in the Standard, "forever."

> 
> Frank

-- 
-Tucker Taft   stt@avercom.net   http://www.avercom.net
Chief Technology Officer, AverCom Corporation (A Titan Company) 
Burlington, MA  USA (AverCom was formerly the Commercial Division of AverStar:
http://www.averstar.com/~stt)