Ada 95 based RTOS

Ada 95 based RTOS

[xaplos]

I am aware of several commercial products integrating Ada with C/C++
based RTOS, but is there any open-source RTOS that is completely written
with the Ada programming language - from the hardware-specific kernel
all the way to the GUI.

I appologize for posting twice: this message and one to a non-related
thread [Ada95-Compiler Recommendation for Win32].

-


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Re: Ada 95 based RTOS

[Tucker Taft]

xaplos@my-deja.com wrote:
> 
> I am aware of several commercial products integrating Ada with C/C++
> based RTOS, but is there any open-source RTOS that is completely written
> with the Ada programming language - from the hardware-specific kernel
> all the way to the GUI.

RTEMS is an RTOS written in Ada, though I don't believe it contains
a GUI (I don't usually associate GUI's with RTOS's, though I guess
that is changing...).  I'm not certain whether RTEMS is open source.
It is available integrated with GNAT.

There are also Ada run-times that are written entirely in Ada from
several of the Ada vendors (e.g. Aonix, DDC-I, Rational, Green Hills
GNAT, etc.).  (NOTE: Some of these are subset Ada run-times designed for
safety-critical systems.)

An Ada run-time system is effectively a special purpose RTOS.  Many
vendors make the source code for their Ada run-time system available
to licensees of their compiler, though it may be an extra cost item.

> 
> I appologize for posting twice: this message and one to a non-related
> thread [Ada95-Compiler Recommendation for Win32].
> 
> -
> 
> Sent via Deja.com http://www.deja.com/
> Before you buy.

-- 
-Tucker Taft   stt@averstar.com   http://www.averstar.com/~stt/
Technical Director, Distributed IT Solutions  (www.averstar.com/tools)
AverStar (formerly Intermetrics, Inc.)   Burlington, MA  USA

Re: Ada 95 based RTOS

[xaplos]

Thank you very much for the reference to RTEMS. I downloaded version 4
only to find out that the source files are in C. I keep reading on
several sites that there is a version of RTEMS written in Ada; however,
I can't find it.

It is my understanding that I can compile Ada source into object files
with GNAT and link them with RTEMS which is written in C to run my
applications on lets say an M68K. Because of the nature of the project
I'm working on - master's thesis - I'd really like to be working with
code from the same language - hence my desire to find the Ada version of
RTEMS.

In article <38ADCA44.3B91BF6F@averstar.com>,
  Tucker Taft <stt@averstar.com> wrote:
> xaplos@my-deja.com wrote:
> >
> > I am aware of several commercial products integrating Ada with C/C++
> > based RTOS, but is there any open-source RTOS that is completely
written
> > with the Ada programming language - from the hardware-specific
kernel
> > all the way to the GUI.
>
> RTEMS is an RTOS written in Ada, though I don't believe it contains
> a GUI (I don't usually associate GUI's with RTOS's, though I guess
> that is changing...).  I'm not certain whether RTEMS is open source.
> It is available integrated with GNAT.
>
> There are also Ada run-times that are written entirely in Ada from
> several of the Ada vendors (e.g. Aonix, DDC-I, Rational, Green Hills
> GNAT, etc.).  (NOTE: Some of these are subset Ada run-times designed
for
> safety-critical systems.)
>
> An Ada run-time system is effectively a special purpose RTOS.  Many
> vendors make the source code for their Ada run-time system available
> to licensees of their compiler, though it may be an extra cost item.
>
> >
> > I appologize for posting twice: this message and one to a
non-related
> > thread [Ada95-Compiler Recommendation for Win32].
> >
> > -
> >
> > Sent via Deja.com http://www.deja.com/
> > Before you buy.
>
> --
> -Tucker Taft   stt@averstar.com   http://www.averstar.com/~stt/
> Technical Director, Distributed IT Solutions  (www.averstar.com/tools)
> AverStar (formerly Intermetrics, Inc.)   Burlington


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Re: Ada 95 based RTOS

[Matthew Majka]

xaplos@my-deja.com wrote:
> 
> Thank you very much for the reference to RTEMS. I downloaded version 4
> only to find out that the source files are in C. I keep reading on
> several sites that there is a version of RTEMS written in Ada; however,
> I can't find it.
> 
> It is my understanding that I can compile Ada source into object files
> with GNAT and link them with RTEMS which is written in C to run my
> applications on lets say an M68K. Because of the nature of the project
> I'm working on - master's thesis - I'd really like to be working with
> code from the same language - hence my desire to find the Ada version of
> RTEMS.

I think I remember hearing that the Ada version of RTEMS is no longer
supported/being updated.  At one point you could chose from sources
in either C or Ada, but apparently the demand for the Ada sources
wasn't large enough to justify the effort of producing them.

Re: Ada 95 based RTOS

[xaplos]

From what I can gather from the http://www.rtems.army.mil the last
version of RTEMS written in Ada was V 3.2.1. I really don't care if it's
being updated or maintained since I'm only planning to use it as a
reference. If anyone has a copy of this release or a later one, please
send it to macrod@earthlink.net - it would help me out considerably.

I'm fairly new to the Ada language and have spent a lot of time reading
how Ada is superior to C/C++ in design and safety. I'm currious if
someone can explain why there are so many RTOS based on C/C++ and "none"
(I mean easily and freely available) based on Ada. With Ada's real-time
annex and other language features, one would think an Ada-based
kernel/run-time would be superior to others.
In article <38B2A2A1.FDCDDFE7@honeywell.com>,
  Matthew Majka <matthew.majka@honeywell.com> wrote:
> xaplos@my-deja.com wrote:
> >
> > Thank you very much for the reference to RTEMS. I downloaded version
4
> > only to find out that the source files are in C. I keep reading on
> > several sites that there is a version of RTEMS written in Ada;
however,
> > I can't find it.
> >
> > It is my understanding that I can compile Ada source into object
files
> > with GNAT and link them with RTEMS which is written in C to run my
> > applications on lets say an M68K. Because of the nature of the
project
> > I'm working on - master's thesis - I'd really like to be working
with
> > code from the same language - hence my desire to find the Ada
version of
> > RTEMS.
>
> I think I remember hearing that the Ada version of RTEMS is no longer
> supported/being updated.  At one point you could chose from sources
> in either C or Ada, but apparently the demand for the Ada sources
> wasn't large enough to justify the effort of pr


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Re: Ada 95 based RTOS

[Stanley R. Allen]

xaplos@my-deja.com wrote:
> 
> I'm fairly new to the Ada language and have spent a lot of time reading
> how Ada is superior to C/C++ in design and safety. I'm currious if
> someone can explain why there are so many RTOS based on C/C++ and "none"
> (I mean easily and freely available) based on Ada. With Ada's real-time
> annex and other language features, one would think an Ada-based
> kernel/run-time would be superior to others.

How about:

    "Against stupidity the gods themselves contend in vain"  -- Schiller

?

-- 
Stanley Allen
mailto:Stanley_R_Allen@raytheon.com

Re: Ada 95 based RTOS

[Ted Dennison]

In article <88ugrd$7j7$1@nnrp1.deja.com>,
  xaplos@my-deja.com wrote:

> how Ada is superior to C/C++ in design and safety. I'm currious if
> someone can explain why there are so many RTOS based on C/C++ and
> "none" (I mean easily and freely available) based on Ada. With Ada's

How many RTOS's are there in *any* language that fit your criteria? Two
maybe? The fact that you can't easily find freely-available sources for
a particular language for either of those two RTOS's can hardly be taken
as having some statisticly significant meaning.

--
T.E.D.

http://www.telepath.com/~dennison/Ted/TED.html


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Re: Ada 95 based RTOS

[xaplos]

My intentions are not to bad-talk Ada in any way - I'm already convinced
its a superior language than C/C++. Your absolutely right in that the
specific requirements for any project (especially an RTOS project)
rarely can be met with an off-the-shelf product. It's just nice to have
some source code available as a reference (especially as a newbie to
Ada) when beginning a new project rather than starting from scratch.

There are several books available on embedded programming that discuss
C/C++ which is really nice for a beginning programming to use as a
starting reference. Even though these books probably won't discuss the
particulars of your project, it's still a nice reference. I just think
having access to Ada sources for low level system programming - like an
RTOS - will help beginners like myself become more familiar with the
capabilities of Ada.

I'm planning on devoting about a 1 to 2 years (probably will be much
more but my wife will kill me if I don't get out of school soon) working
on an open-source OS written entirely in Ada for wireless devices
(similar to the Palm OS, Windows CE, Epoc OS, etc.). I'd like the entire
project to be based on Ada from the low-level kernel and memory
management all the way to the programming API and GUI. I strongly
believe Ada is a perfect language for these types of consumer appliances
for obvious reasons. I don't expect to find any RTOS that will meet my
all of my requirements for this project; however, having access to the
Ada sources for RTEMS would be a great starting point.

In article <88umb5$c5p$1@nnrp1.deja.com>,
  Ted Dennison <dennison@telepath.com> wrote:
> In article <88ugrd$7j7$1@nnrp1.deja.com>,
>   xaplos@my-deja.com wrote:
>
> > how Ada is superior to C/C++ in design and safety. I'm currious if
> > someone can explain why there are so many RTOS based on C/C++ and
> > "none" (I mean easily and freely available) based on Ada. With Ada's
>
> How many RTOS's are there in *any* language that fit your criteria?
Two
> maybe? The fact that you can't easily find freely-available sources
for
> a particular language for either of those two RTOS's can hardly be
taken
> as having some statisticly significant meaning.
>
> --
> T.E.D.
>
> http://www.telepath.com/~dennison/Ted/TED.html
>
> Sent via Deja.com http://www.deja.co


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Re: Ada 95 based RTOS

[Marin D. Condic]

xaplos@my-deja.com wrote:
> I'm fairly new to the Ada language and have spent a lot of time reading
> how Ada is superior to C/C++ in design and safety. I'm currious if
> someone can explain why there are so many RTOS based on C/C++ and "none"
> (I mean easily and freely available) based on Ada. With Ada's real-time
> annex and other language features, one would think an Ada-based
> kernel/run-time would be superior to others.

In many realtime and embedded applications, the tradition has been for
the Ada compiler to provide a runtime kernel which implements the
tasking primitives and similar features needed to make the code run on a
bare machine. This is a little different than the tradition with C/C++
compilers that rode on top of Unix (and others) and someone else would
provide a plug-compatible kernel as a separate piece. Many Ada compilers
have been targeted to unique hardware or somewhat obscure processors so
an RTOS would have been hard to develop that fit all those niches. Hence
reliance on a compiler provided RTK.

You may discover that there are Ada compilers out there which target
your favorite C/C++ based RTOS. An RTOS is, after all, nothing more than
another operating system. Just as you can target many languages to Unix,
you can target Ada to run on top of any RTOS. Check with some of the
compiler vendors. There are links to many of them on my web page.

MDC
-- 
=============================================================
Marin David Condic   - Quadrus Corporation -   1.800.555.3393
1015-116 Atlantic Boulevard, Atlantic Beach, FL 32233
http://www.quadruscorp.com/
m c o n d i c @ q u a d r u s c o r p . c o m

***PLEASE REMOVE THE "-NOSPAM" PART OF MY RETURN ADDRESS***

Visit my web site at:  http://www.mcondic.com/

"Because that's where they keep the money."
    --  Willie Sutton when asked why he robbed banks. 
=============================================================

Re: Ada 95 based RTOS

[Tarjei T. Jensen]

xaplos@my-deja.com wrote
>I'm fairly new to the Ada language and have spent a lot of time reading
>how Ada is superior to C/C++ in design and safety. I'm currious if
>someone can explain why there are so many RTOS based on C/C++ and "none"
>(I mean easily and freely available) based on Ada. With Ada's real-time
>annex and other language features, one would think an Ada-based
>kernel/run-time would be superior to others.

If your read (and believe) what the Jargon file
(http://www.tuxedo.org/~esr/jargon/) writes about Ada then it is not surprising
that languages like Ada are not popular with the hackers. Ada has had a
terrible reputation. To me the Ada vendors seems to have been very lethargic -
perhaps unable to to long term planning. Why should they, Uncle Sam seems to
have been very generous to many.

It is with GNAT that we have the means to show how great a language Ada is. The
availability of GNAT gives the Ada community a low cost Ada compiler which can
be the basis for long term work (10+ years) to increase Ada usage.

The increased use of Ada in education seems to have given good results and
there is a steady increase in projects that is done in Ada. The Adapower site
should be a good indication of this.

If this trend continues it is not unthinkable that Ada reaches the mainstream
within the next 5 years. With an expanding user base in eduation it is probably
a matter of time before we get an application which will force people to want
to learn Ada (like Zope has done for Python).


Greetings,

Re: Ada 95 based RTOS

[Gautier]

> If your read (and believe) what the Jargon file
> (http://www.tuxedo.org/~esr/jargon/) writes about Ada then it is not surprising
> that languages like Ada are not popular with the hackers. Ada has had a
> terrible reputation.

An interesting thing is that these impressions seem to be just based on gossips
(Ada 83, with the first compiler attempts) or simply copied from the criticism
about Pascal - which is somehow justified for Pascal.
A fundamental reason why fundamental things do not change in software as fast as
for other technical domains is that an ASCII text even doesn't become yellow with
the time. The "Ada" topic in the Jargon file must be about 20 years old, but a
newcomer could take it as fresh information... Anyway the whole text smells
its 1970-early 1980, with plenty of PDP-11 and so on... Maybe for the "Elderly
Hackers Club" ?...

-- 
Gautier

_____\\________________\_______\_________
http://members.xoom.com/gdemont/gsoft.htm

Re: Why should hackers love Ada. (Re: Ada 95 based RTOS)

[Vladimir Olensky]

Marin D. Condic wrote in message <38B41432.88D7389F@quadruscorp.com>...

>But I suppose those who would hang the moniker "hacker" upon themselves
>really want assembly language - only without the inconvenience of having
>to learn a new one every time new hardware comes out. Hence the
>popularity of things like C with hackers.
>


There even exists HLA (High Level Assembler) project which is nothing
more than new  variation of   C.
Intention is to use it instead of different assemblers.

Regards,
Vladimir Olensky

Re: Ada 95 based RTOS

[Ted Dennison]

In article <890ght$bih1@ftp.kvaerner.com>,
  "Tarjei T. Jensen" <tarjei.jensen@kvaerner.com> wrote:
>
> If your read (and believe) what the Jargon file
> (http://www.tuxedo.org/~esr/jargon/) writes about Ada then it is not

You shouldn't. This has come up before. ESR is not particularly Ada
friendly, and his jargon file is mainly his feelings on the defnitions
of things. He's a clever guy, but he doesn't know everything. So the
stuff in the jargon file is often quite off the mark.

I much prefer to refer people to FOLDOC (
http://foldoc.doc.ic.ac.uk/foldoc/mirrors.html ), which takes
submissions from anyone. Its much more comprehensive, better maintained,
and wittier.

--
T.E.D.

http://www.telepath.com/~dennison/Ted/TED.html


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Re: Why should hackers love Ada. (Re: Ada 95 based RTOS)

[Gautier]

> There even exists HLA (High Level Assembler) project which is nothing
> more than new  variation of   C.
> Intention is to use it instead of different assemblers.

There is also C-- http://www.research.microsoft.com/~simonpj/c--.html
(IMHO: whatever ++,--,... it is always a macro-assembler...)

BTW: Ada is also good for hacking. The "'range" & so attributes allow
to write faster your code, with less thinking, and obtain almost immediately
working code-cracking applets. In addition: understandable after 6 months,
even with poor formatting!

-- 
Gautier

_____\\________________\_______\
http://members.xoom.com/gdemont/

Re: Why should hackers love Ada. (Re: Ada 95 based RTOS)

[Gary]

Hi,

"Marin D. Condic" wrote:

> Ehud Lamm wrote:
> >
> In some ways, you'd think "hackers" should be fascinated with Ada. It
> provides all sorts of facilities to do bit-twiddling and low level
> access to the hardware.

I see this reference to ADA being good at bit twiddling, periodically.
Virtually all high-level languages provide facilities for bit twiddling.  Is
there something unique about ADA (I'm a non-ADA programmers, sorry).  Is this
a reference to a transfer function (other languages have this) or memory
aliasing tricks?

Re: Ada 95 based RTOS

[Ehud Lamm]

Hi

I have a rough outline for a memo titled "Why should hackers love Ada."
Beacuse of lack of time, it is yet to be finished. If someone wants to
cooperate - let me konw

Ehud Lamm mslamm@mscc.huji.ac.il
http://purl.oclc.org/NET/ehudlamm <== My home on the web 
Check it out and subscribe to the E-List- for interesting essays and more!


On Wed, 23 Feb 2000, Gautier wrote:

|> If your read (and believe) what the Jargon file
|> (http://www.tuxedo.org/~esr/jargon/) writes about Ada then it is not surprising
|> that languages like Ada are not popular with the hackers. Ada has had a
|> terrible reputation.
|
|An interesting thingis that these impressions seem to be just based on gossips
|(Ada 83, with the first compiler attempts) or simply copied from the criticism
|about Pascal - which is somehow justified for Pascal.
|A fundamental reason why fundamental things do not change in software as fast as
|for other technical domains is that an ASCII text even doesn't become yellow with
|the time. The "Ada" topic in the Jargon file must be about 20 years old, but a
|newcomer could take it as fresh information... Anyway the whole text smells
|its 1970-early 1980, with plenty of PDP-11 and so on... Maybe for the "Elderly
|Hackers Club" ?...
|
|-- 
|Gautier
|
|_____\\________________\_______\_________
|http://members.xoom.com/gdemont/gsoft.htm
|
|

Re: Ada 95 based RTOS

[Roger Racine]

On Tue, 22 Feb 2000 20:14:11 GMT, xaplos@my-deja.com wrote:

>My intentions are not to bad-talk Ada in any way - I'm already convinced
>its a superior language than C/C++. Your absolutely right in that the
>specific requirements for any project (especially an RTOS project)
>rarely can be met with an off-the-shelf product. It's just nice to have
>some source code available as a reference (especially as a newbie to
>Ada) when beginning a new project rather than starting from scratch.
>
>There are several books available on embedded programming that discuss
>C/C++ which is really nice for a beginning programming to use as a
>starting reference. Even though these books probably won't discuss the
>particulars of your project, it's still a nice reference. I just think
>having access to Ada sources for low level system programming - like an
>RTOS - will help beginners like myself become more familiar with the
>capabilities of Ada.
>
>I'm planning on devoting about a 1 to 2 years (probably will be much
>more but my wife will kill me if I don't get out of school soon) working
>on an open-source OS written entirely in Ada for wireless devices
>(similar to the Palm OS, Windows CE, Epoc OS, etc.). I'd like the entire
>project to be based on Ada from the low-level kernel and memory
>management all the way to the programming API and GUI. I strongly
>believe Ada is a perfect language for these types of consumer appliances
>for obvious reasons. I don't expect to find any RTOS that will meet my
>all of my requirements for this project; however, having access to the
>Ada sources for RTEMS would be a great starting point.
>

A company called TopLayer (www.toplayer.com) has a RTOS based on the
GNAT runtime system.  Mike Kamrad of that company has given a couple
talks at Ada conferences on the subject.  

I am not sure about the license issues.  Their code has "all rights
reserved", but it was based on the GNAT source.  The GNAT source has
pretty open language, but definitely -not- GPL (since it is expected
to be used as a library), so the TopLayer code does not appear to be
"open by extension".

Roger Racine

Re: Why should hackers love Ada. (Re: Ada 95 based RTOS)

[Marin D. Condic]

Ehud Lamm wrote:
> 
> Hi
> 
> I have a rough outline for a memo titled "Why should hackers love Ada."
> Beacuse of lack of time, it is yet to be finished. If someone wants to
> cooperate - let me konw
> 
In some ways, you'd think "hackers" should be fascinated with Ada. It
provides all sorts of facilities to do bit-twiddling and low level
access to the hardware. Tasks seem to provide ample opportunity for
playing with sophisticated OS or OS-like features. The control of the
representation of data down to bits, endianness, etc. ought to appeal to
people who like to get control of the bare machine.

But I suppose those who would hang the moniker "hacker" upon themselves
really want assembly language - only without the inconvenience of having
to learn a new one every time new hardware comes out. Hence the
popularity of things like C with hackers.

MDC
-- 
=============================================================
Marin David Condic   - Quadrus Corporation -   1.800.555.3393
1015-116 Atlantic Boulevard, Atlantic Beach, FL 32233
http://www.quadruscorp.com/
m c o n d i c @ q u a d r u s c o r p . c o m

***PLEASE REMOVE THE "-NOSPAM" PART OF MY RETURN ADDRESS***

Visit my web site at:  http://www.mcondic.com/

"Because that's where they keep the money."
    --  Willie Sutton when asked why he robbed banks. 
=============================================================

Re: Ada 95 based RTOS

[Simon Wright]

rracine@myremarq.com (Roger Racine) writes:

> I am not sure about the license issues.  Their code has "all rights
> reserved", but it was based on the GNAT source.  The GNAT source has
> pretty open language, but definitely -not- GPL (since it is expected
> to be used as a library), so the TopLayer code does not appear to be
> "open by extension".

"GNAT is free software; you can redistribute it and/or modify it under
 terms of the GNU General Public License ...

"As a special exception,  if other files  instantiate  generics from this 
 unit, or you link  this unit with other files  to produce an executable, 
 this  unit  does not  by itself cause  the resulting  executable  to  be 
 covered  by the  GNU  General  Public  License.  This exception does not 
 however invalidate  any other reasons why  the executable file  might be 
 covered by the  GNU Public License. ...

IANAL but seems to me that if I were to base my code on the GNAT
sources it would definitely come under the GPL. However, if I just use
functionality provided by the GNAT sources, that's a different matter.

Re: Why should hackers love Ada. (Re: Ada 95 based RTOS)

[Gisle S�lensminde]

In article <38B47521.1A80B6A1@lmtas.lmco.com>, Gary wrote:
>Hi,
>
>"Marin D. Condic" wrote:
>
>> Ehud Lamm wrote:
>> >
>> In some ways, you'd think "hackers" should be fascinated with Ada. It
>> provides all sorts of facilities to do bit-twiddling and low level
>> access to the hardware.
>
>I see this reference to ADA being good at bit twiddling, periodically.
>Virtually all high-level languages provide facilities for bit twiddling.  Is
>there something unique about ADA (I'm a non-ADA programmers, sorry).  Is this
>a reference to a transfer function (other languages have this) or memory
>aliasing tricks?
>

Because Ada heve some good methods for lowlevel access to hardware, and
this includes bit twidling. Some bit operations are:   

- Bitwise logical operators for modular types, and in the package interfaces 
  there is operators for bitwise shift and rotatate.

- Packed arrays of boolean(and other types). Yoy can declare an array of
  booleans, where each element corresponds to one bit. A 32-bit array of
  packed booleans fits in one word on a 32-bit computer.

- The compiler knows whether the target is a big endian or a little endian
  architecture, and you have tests to find it out, which can be used in code
  to make it portible.

- Representation clauses in records, so you can control where
  "the bits goes" in a record.
  

--
Gisle S�lensminde ( gisle@ii.uib.no )   

ln -s /dev/null ~/.netscape/cookies

Re: Why should hackers love Ada. (Re: Ada 95 based RTOS)

[David C. Hoos, Sr.]

Vladimir Olensky <vladimir_olensky@yahoo.com> wrote in message
news:sb8gj38sr2a132@corp.supernews.com...
>
> Marin D. Condic wrote in message <38B41432.88D7389F@quadruscorp.com>...
>
> >But I suppose those who would hang the moniker "hacker" upon themselves
> >really want assembly language - only without the inconvenience of having
> >to learn a new one every time new hardware comes out. Hence the
> >popularity of things like C with hackers.
> >
>
>
> There even exists HLA (High Level Assembler) project which is nothing
> more than new  variation of   C.
> Intention is to use it instead of different assemblers.
>
Are you confusing the term HLA with that of High-Level Architecture,
described in the following paragraphs from the project website?
http://www.sisostds.org/stdsdev/hla/

If not, where can one get information about High Level Assembler?


The High Level Architecture (HLA) has been developed with the
objective of providing a common architecture applicable across
all classes of simulation to support simulation interoperability
and reuse. The HLA is defined by the following three draft standards:

Framework and Rules - IEEE Standard P1516: The HLA rules describe the
responsibilities of federates (simulations, supporting utilities, or
interfaces to live systems) and federations (sets of federates
working together to support distributed applications). The rules
comprise a set of underlying technical principles for the HLA. For
federations, the rules address the requirement for a federation
object model (FOM), object ownership and representation, and data
exchange. For federates, the rules require a simulation object model
(SOM), time management in accordance with the HLA Runtime
Infrastructure (RTI) time management services, and certain required
functionality and constraints on attribute ownership and updates.

Federate Interface Specification - IEEE Standard P1516.1: In the HLA,
federates interact with an RTI (analogous to a special-purpose
distributed operating system) to establish and maintain a federation
and to support efficient information exchange among simulations and
other federates. The HLA interface specification defines the nature
of these interactions, which are arranged into sets of basic RTI
services.

Object Model Template (OMT) Specification - IEEE Standard P1516.2:
The HLA requires simulations (and other federates) and federations
to each have an object model describing the entities, not
necessarily platform entities, represented in the simulations and
the data to be exchanged across the federation. The HLA object
model template prescribes the method for recording the information
in the object models, to include objects, attributes, interactions,
and parameters, but it does not define the specific data (e.g.,
vehicles, unit types) that will appear in the object models.

Re: Why should hackers love Ada. (Re: Ada 95 based RTOS)

[Vladimir Olensky]

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David C. Hoos, Sr. wrote in message ...
>
>Vladimir Olensky <vladimir_olensky@yahoo.com> wrote in message
>news:sb8gj38sr2a132@corp.supernews.com...
>>
>> Marin D. Condic wrote in message <38B41432.88D7389F@quadruscorp.com>...
>>
>> >But I suppose those who would hang the moniker "hacker" upon themselves
>> >really want assembly language - only without the inconvenience of having
>> >to learn a new one every time new hardware comes out. Hence the
>> >popularity of things like C with hackers.
>> >
>>
>>
>> There even exists HLA (High Level Assembler) project which is nothing
>> more than new  variation of   C.
>> Intention is to use it instead of different assemblers.
>>
>Are you confusing the term HLA with that of High-Level Architecture,
>described in the following paragraphs from the project website?
>http://www.sisostds.org/stdsdev/hla/


Not at all.

   But I should admit that I was  wrong  that HLA is another
version of C :-(.
Something wrong switched on in my mind.

  HLA is some mix of different syntax features but it
looks more like  Ada than C.

  See below some notes where author  explains why HLA
looks more like Ada than C.

Ada people would be pleased with that words.

And that is just about "Why should hackers love Ada" :-)

>If not, where can one get information about High Level Assembler?


Pas de probleme.

Below is what I've extracted from my archive.

=================================================
From: Randall Hyde <rhyde@shoe-size.com>
Subject: High Level Assembly FAQ
Date: 9 ������ 1999 �. 6:58

=============================================================
The High Level Assembly Frequently Asked Questions (FAQ) List
=============================================================

This document describes the HLA (High Level Assembly)
language.  Many of these questions were asked in newsgroups
or email, some questions are simply "anticipated" questions
injected to help describe the HLA system.

-------- Purpose and General Questions ----------------------

1:  q.  Where do you get a copy of HLA
    a.  http://webster.cs.ucr.edu
        Following the High Level Assembly links.

2:  q.  What is HLA?
    a.  HLA is a high level assembly language.  It uses
        a high level language like syntax (similar to
        Pascal, C/C++, and other HLLs) for variable
        declarations, procedure declarations, and
        procedure calls.  It uses a modified assembly
        language syntax for the standard machine
        instructions.  It also provides several high
        level language style control structures (if,
        while, repeat..until, etc.) that help you
        write much more readable code.

3:  q.  Doesn't the presence of HLL control structures
        technically make HLA a high level language?
    a.  These control structures are similiar to those
        provide by MASM and TASM (indeed, HLA's are
        weaker in some respects).  So unless you're
        willing to call MASM and TASM high level
        languages, it doesn't make sense to call HLA a
        high level language.  Definitely, though, HLA
        provides a syntax that is usually "higher level"
        that that provided by MASM or TASM (even in
        TASM's IDEAL mode).

4:  q.  HLA programs look like Pascal.  Why didn't you
        make them look more like C/C++?
    a.  Actually, they look more like Ada or Modula-2
        than Pascal, but to answer the real question,
        Pascal is a much cleaner, easier to read language
        that C/C++.  The intent was to create an
        assembly language that allows the creation of
        readable programs.  The Pascal/Modula-2/Ada
        branch of the programming languages tree is
        generally acknowledged as producing more readable
        programs than the C/C++ branch.

5:  q.  But there are more C/C++ programmers today than
        Pascal programmers.  Don't you think that using
        a C/C++ based syntax would have made HLA easier
        to learn by most people?
    a.  No.
        HLA is only superficially related to Pascal.
        While Pascal programmers might have a tiny
        advantage when learning HLA, the majority of
        the learning effort is in other areas (like
        learning machine language) rather than
        learning Pascal's procedure declaration syntax
        vs. C/C++'s (about the only area where Pascal
        programmers have a real advantage).

6:  q.  Why is HLA necessary?  What's wrong with MASM,
        TASM, GAS, or NASM?  Do we really need another
        incompatible assembler out there?
    a.  HLA was written with two purposes in mind: The
        first was to provide a tool that makes it very
        easy (or, at least, easier) to teach assembly
        language programming to University students.
        Experiences at UCR bear out the success of
        HLA's design (even with prototype/alpha code
        with tons of bugs and little documentation,
        students are producing better projects than
        past courses that used MASM).  The second
        purpose was to provide a tool for very
        serious, code-quality-conscious programmers
        who want to write very powerful applications
        in assembly language (as opposed to the
        "DOS Hackers" who are still worrying about the
        fastest "sieve" program or the fastest integer
        to ASCII translation routine that can be
        written.

        What's wrong with MASM, TASM, GAS, and NASM?
        (a) Their very syntax encourages people to
        write unreadable programs (if you don't believe
        me, look at the code being posted to the net).
        (b) Their macro facilities are non-existent
        to moderate.  They don't, for example support
        the creation of DSELs (domain specific embedded
        languages) very well.

        As to whether another incompatible assembler
        is good or bad, well, that toothpaste is
        already out of the tube and there is no
        putting it back.  If you've got two incompatible
        assemblers, you may as well have three or four.
        Certainly, there was no good reason to attempt
        to make HLA compatible with an existing product.
        The whole point of HLA was to start fresh, not
        carry around a lot of old baggage from the
        late '70s (when Microsoft's first assemblers
        started appearing).

7:  q.  Is HLA intended for high level language programmers?
    a.  Only in the sense that a HLL programmer who
        doesn't know assembly language will probably
        have an easier time learning HLA rather than, say,
        MASM.

        Otherwise, HLA is not intended for HLLs at all.
        While you can certainly write assembly language
        modules in HLA that link to other HLLs, HLA was
        specifically designed to let you write stand-alone
        application in assembly language under Win32.

8:  q.  HLA looks like BASM in Delph.  What relationship
        does it have to BASM?
    a.  None whatsoever at all.  Indeed, HLA only superficially
        looks like BASM.  Most likely, this confusion exists
        because HLA looks like Pascal.

9:  q.  HLA looks like it will save your students a lot of
        effort learning.  Since the amount of information
        learned is usually directly proportional to the
        effort extended in learning the subject, don't you
        feel you are shortchanging your students by letting
        them use an assembler that requires less effort to
        learn?
    a.  If I had a fixed amount of material to teach and I
        stopped once the material was covered, this observation
        would be correct.  However, in the University I have
        a fixed amount of time for teaching, not a fixed
        amount of material to cover.  By making the learning
        process more efficient, I can cover more material
        and get farther along in the same amount of time.

10: q.  Students writing code with IF, WHILE, and FOR statements
        aren't writing true assembly language code.  They
        are missing much of what assembly is about at that
        point.  This isn't teaching assembly, this is teaching
        another mid-level language like C.
    a.  This is true.  A good instructor will not allow students
        to continue using HLA's high level language control
        structures throughout the term.  However, they come in
        very handy at the beginning of the term because they
        allow students to write meaningful programs using a
        programming paradigm they already understand before
        they've had time to assimilate the entire instruction
        set.

11: q.  Does HLA run under DOS?
    a.  No.  It only runs under Win32.


12: q.  Does HLA run under Win 3.11?
    a.  No.  It only runs under Win32.  That would be Windows 95, 98,
        NT, and 2000 (and probably later versions as well).

13: q.  Why didn't you write it so that it runs under DOS?
    a.  DOS is truly dead at this point.  Most die-hard assembly
        language programmers still work in DOS because DOS is easy
        to program in assembly language and there is a large
        amount of programming information associated with DOS.
        A major point of HLA is that it is intended to make
        Windows programming as easy as DOS in assembly language.
        Currently, HLA does a good job of this with console apps.

14: q.  Does HLA support console application programming?
    a.  Yes.  Very well.  The console module in the HLA Standard
        Library is especially powerful.

15: q.  Does HLA support graphics/GUI Windows application
        programming?
    a.  There is nothing in the language that prevents you from
        writing graphical applications.  At the current time,
        however, the HLA Standard Library doesn't provide much
        support for GUI apps.  This will change with time.

16: q.  Do you provide an application framework like OWL, MFC,
        or VCL for use with HLA?
    a.  See the above answer.

17: q.  Is HLA Shareware?
    a.  No.  HLA is free.

18: q.  Is HLA GPL'd?
    a.  No.  You are free to do whatever you want with it.
        GPL puts a lot of restrictions on the code that
        I don't particularly agree with.

19: q.  Is HLA public domain?
    a.  No.  I (Randall Hyde) retain the copyright.
        However, I allow you to distribute the release
        package with no restrictions whatsoever.

20: q.  Is the source code available?
    a.  Not yet.  I am currently putting together a formal
        test suite for HLA and I don't want to release
        the source code until I get the product tested
        better.

21: q.  Why not use the services of all the programmers
        on the net to test and debug your program, as has
        happened for Linux, NASM, and other Open Source
        projects?
    a.  The HLA system is currently in excess of 100,000
        lines of code.  Part of this is due to inappropriate
        choice of programming language (FLEX/Bison), part
        of the size is due to sloppy coding, part of the
        size is due to the fact that HLA is a big language.
        I had to pull a lot of tricks with Flex and Bison
        in order to implement the language.  The code is
        not easy to follow and easy to mess up if one isn't
        careful.  It took me over three years to create this
        mess and I suspect it would take someone at least
        a year to figure out what I've done (never mind
        why I did it).  By the time someone could really be
        providing useful help, I'll have the testing finished
        on my own.  Then I'll release the sources.

22: q.  Earlier you talked about writing readable code.  Why
        didn't you follow your own advice on the HLA source?
    a.  HLA is currently a prototype.  A prototype is a
        program you write in order to test ideas out.  I've
        been testing lots of ideas for over three years now.
        Many ideas have worked, many have failed, some have
        succeeded only through the application of brute force.
        However, the end result of all this experimentation
        is a grand kludge.  The saying "always prepare to
        write your program twice, because you will..."
        certainly applies here.  My prototype is the first
        version of the program.  Version 2.0 will have to
        be a complete rewrite, applying what I've learned.

23: q.  What are the other implications of a "prototype"
        piece of software?
    a.  I don't have any problems changing the syntax of
        the language in such a way that it renders existing
        code uncompilable.  I've done this on several
        occasions already, it will likely happen in the
        future.

24: q.  What is the current version?
    a.  The current version changes so often that any
        attempt to specify it here would produce something
        that is completely out of date.  Go to Webster
        and you can find the latest version there.

25: q.  You keep calling HLA a compiler.  Aren't translators
        for assembly language called assemblers?
    a.  In general, yes;  HLA should be called an assembler.
        However, the internal design is that of a compiler
        rather than an assembler.  Combined with the fact that
        HLA produces assembly code, not object code, the label
        "compiler" just seems to be a better fit.

26: q.  What do you need in order to use HLA?
    a.  You need to be running a Win32 OS.  You need the HLA
        distribution package.  You need MASM and a 32-bit
        version of MS-link.  You also need some Windows
        DLL libraries like Kernel32.lib.  All of these files
        are available free on the Internet.

27: q.  Does HLA work with TASM?
    a.  Kind of.  The "m2t" (MASM to TASM)  post-processor
        program converts the HLA MASM output to a form that
        will compile under TASM 4.0 (and later, hopefully).
        However, since MASM is freely available from Microsoft
        on the Internet, bother to use TASM seems hardly worthwhile.

28: q.  Does HLA work with NASM?
    a.  No.  Feel free to modify "m2t" to produce "m2n", though.
        However, since MASM is *still* free, this doesn't seem
        worth the effort.

29: q.  MASM is a disgusting assembler.  Why do you force us to
        use it?
    a.  MASM, NASM, GAS, or TASM.  The choice is irrelevant since
        HLA automatically emits the MASM code, runs MASM, and
        links the code to produce an executable.  You don't write
        MASM code and you don't run MASM.  So unless you simply
        hate Microsoft and don't want to run the software they
        are giving you for free "just because,"  you don't have
        to worry about what assembler you're using.

30: q.  Microsoft software is big and slow.  Why force us to use
        it in order to use HLA?  We'd prefer to use more
        efficient code.
    a.  If you don't like MASM and LINK, you'll really hate
        HLA.  MASM and LINK are faster than HLA.  Remember, HLA
        is a prototype.  No effort was made to make it efficient.



--------- Language Specific Questions -----------------------------

1:  q.  Could you give an example of a simple HLA program?
    a.  Here's the HelloWorld program:

        program helloWorld;
        #include( "stdlib.hhf" );

        begin helloWorld;

            stdout.put( "Hello World" nl );

        end helloWorld;


2:  q.  Wait a second! There aren't any real machine instructions here!
        This isn't assembly language.
    a.  Okay, here's the version in "real" machine code, still using
        HLA:

        program helloWorld;
        #include( "stdlib.hhf" );

        static

            hw: string := "Hello World" nl;

        begin helloWorld;

            push( hw );
            call stdout.puts;

        end helloWorld;

        Feel better?  HLA lets you specify HLL-like procedure calls
        and it will automatically push the parameters on the stack
        for you.  This is very similiar to the "invoke" statement
        MASM and TASM (although I personally feel that HLA's syntax
        is cleaner, clearer, and easier to read).  If you really like,
        you can always explicitly write the assembly instructions
        yourself.  However, there is little benefit to doing so.

3:  q.  Isn't it inefficient to pass parameters on the stack?
    a.  In some cases yes.  But if the procedure you're calling
        expects parameters on the stack, whether the compiler pushes
        them or you push them, there is hardly any difference.

4:  q.  The statement <<hw:string:="Hello World" nl;>> hardly looks
        like machine code, explain this.
    a.  Note that <<hw byte "Hello World",13,10,0>> is no more a
        machine instruction than is the HLA declaration.  Semantically,
        the two are equivalent and they generate nearly the same
        machine code (actually, HLA strings aren't simply zero-
        terminated arrays of characters; but ignoring that...).
        Syntactically, however, HLA turns out to be much easier
        to read.

5:  q.  Initialized data in the static section appears to be typed.
        What if I want to go wild and put untype, unstructured
        data into my program?
    a.  Initialized data in the static section is indeed typed.
        You cannot initialize a string variable with a floating
        point numeric value (for example).  However, HLA provides
        a second type of data initialization section, the "data"
        section, that allows the creation of unstructured
        initialized data.  Since most data is structured, you
        will rarely use this feature in the language.

6:  q.  Why the parentheses around the push operand?
    a.  HLA instructions are "composable".  This means that
        you can often supply one instruction as the
        operand of another instruction.  For example, consider
        the following statements:

        mov( 0, eax );
        mov( eax, ebx );

        These could be rewritten as:

        mov( mov( 0, eax ), ebx );

        The interior mov instruction returns its destination
        operand for use as the operand the instruction represents.
        That is, HLA substitutes "eax" for "mov( 0, eax )" in the
        statement above.  This funny looking statement generates
        exactly the same two instructions as the two separate
        mov instructions above it.

7:  q.  This doesn't look very readable.
    a.  No, it is not.  This feature needs to be used with extreme
        care or you can quickly produce an unreadable mess.
        However, composition of instructions is *very* useful
        in certain special cases.

8:  q.  The operands are backwards in your examples.
    a.  No they are not.  You're simply used to Intel syntax
        whose operands are generally orderd "instr dest, src".
        HLA reverses this order to obtain "instr( src, dest )"
        which is a little more intuitive for most instructions.

9:  q.  What happens with those instructions where the src,dest
        ordering is not intuitive?
    a.  HLA uses dest, src ordering.  The two primary examples
        are "cmp( dest, src )" and "lea( dest, src )".

10: q.  Wait, this is horrible!  You're saying that you're
        inconsistent with the order of the operands?
    a.  No.  Intel was inconsistent with the operands.  They
        got lea and cmp right, almost everything else was wrong;
        at least if you consider the English pronouciation of
        the instruction to provide the "inituitive" ordering.
        We generally say "move source to dest", not "move dest
        from source".  Likewise, we normally say "compare dest
        to source" (I can't even rephrase this with the operands
        reversed, forgive me).  I usually say "load a register
        with an effective address."  Hence the HLA syntax.

11: q.  Your choice of the lea operand order is really bad.
        What if we say "load effective address into register."
    a.  Fine, you can say that.  I don't and I wrote the assembler
        so I got to choose.

12: q.  That makes your assembler harder to learn.
    a.  I disagree, but if you're really hung up on this *one*
        instruction (to date, no one has complained about cmp),
        you can easily write a macro to fix this problem.
        Consider the following macro for "sea" (store effective
        address):

        macro sea( source, dest );

            lea( dest, source )

        endmacro;

        Now your problems are solved.  If you feel you must use the
        lea mnemonic, you've got two choices: (1) write a preprocessor
        to fix the syntax (very easy using HLA's pattern matching code)
        or (2) wait until the sources are available and change the
        source code.

13: q.  Why didn't you use "sea" to begin with.
    a.  For pedagogical reasons, I wanted to stick with instruction
        mnemonics that were upwards compatible with Intel's.  As
        a new version of "Art of Assembly" using HLA is still quite
        a ways off, using Intel mnemonics allows students to look
        up an instruction by name and read about its semantics.
        True, the syntax is different, but providing a handout with
        HLA syntax is a much smaller task than providing a handout
        explaining what each instruction does.

14: q.  Doesn't this (lack of good book explaining HLA syntax and
        semantics) make life hard on your students?
    a.  Number one complaint.  With time, this will go away (i.e., as
        I bring various chapters of AoA/HLA on-line.

15: q.  Looking though the HLA documentation suggests that HLA
        supports instructions like "mov(mem, mem);", "pea( mem );",
        "mul( 10, ax );"  These machine instructions do not exist
        on the 80x86.  What's going on here.
    a.  Although I made sure I supported almost all of the Intel
        instructions by name, by no means did I limit myself to
        only using Intel mnemonics.  Once I covered the basic
        Intel instruction set, I took some liberties and added
        a few new instructions.

        mov( mem1, mem2 ), for example, compiles to

            push( mem1 );
            pop( mem2 );

        (this only supports 16- and 32-bit operands.)

        pea( mem ) compiles to

            push( eax );
            lea( mem );
            xchg( eax, [esp] );

        and finally, "mul( 10, eax );" compiles to

            static tempName:dword := 10; endstatic;
            mul( tempName, eax );

16: q.  Isn't compiling code like this inefficient?
    a.  If you abuse it, yes, there can be some slight inefficiencies.
        No one is putting a gun to your head and forcing you to use
        these new instructions or syntaxes, however.

17: q.  MASM has a nasty habit of changing instructions behind your
        back.  HLA also seems to have this same problem.
    a.  Yes and no.  Once again, if you stick to straight Intel
        instructions, HLA emits exactly what you specify.  However,
        HLA emits MASM assembly code, so MASM may do a number on
        your code afterwards.

        In general, I have plans of adding a data flow analyzer
        and an optimizer around version three of HLA.  While I
        certainly intend to provide source level control of the
        optimizer, if you are offended by an assembler that
        plays with your source code, then HLA is not for you.
        On the other hand, if you would like to be able to write
        readable code and leave it up to the compiler to deal
        with instruction scheduling and peep-hole optimizations,
        HLA will be a big win.


18: q.  Does HLA support decent macro facilities?
    a.  Yes.  HLA supports the best macro facilities of any
        programming language I have personally seen.  The
        macro facilities are so powerful, you can easily
        extend the language with it.  For example, the HLA
        Standard Library includes a macro that provides
        a C/C++ style switch statement.  Try doing that
        (easily and effectively) in MASM.

19: q.  What high level language statements does HLA support?
    a.  if..then..elseif..else..endif, while..endwhile, for..endfor,
        forever..endfor, foreach..endfor, repeat..until, break,
        breakif, continue, continueif, context..exit/exitif..endcontext,
        and try..exception..endtry.

20: q.  What about statements like

            stdout.put("hello world" nl );


    a.  These aren't actually statements in the HLA language.  Instead,
        these types of statements are either procedure calls or
        macros provided by the HLA Standard Library.  The HLA
        Standard Library, and the way it extends the HLA language,
        provides a good example of the power of HLA's macros and
        HLL syntax.


21: q.  Why doesn't the statement

            if( ax == bx && cx < dx ) then ... endif;

        work properly?

    a.  HLA does not allow complex expressions like this.  In particular,
        the conjunction operator ("&&") is not allowed here.

22: q.  MASM allows this in it's .if statement.
    a.  Yes it does.  I chose not to implement this because HLA's
        HLL statements are intended as a crutch for students who
        are just learning assembly.  However, I don't want the
        students writing arbitrary C/C++ programs in HLA.  I want
        to force them to think in assembly rather than in C/C++.
        HLA's boolean expressions limit you to the types of operands
        that are legal in a compare instruction.  This better prepares
        the students for when they have to use compares and conditional
        jumps in place of the HLL statements.

23: q.  For those of us that are advanced and understand this conversion,
        this seems somewhat limiting.  What if we want to use HLA's
        HLL control structures to write more readable code?
    a.  HLA provides another syntax that lets you implement arbitrary
        expressions by combining HLL syntax with low level syntax.  The
        previous example could be written as:

            if
            {
                cmp( ax, bx );
                jne false;
                cmp( cx, dx );
                jnb false;
            }
                .
                .
                .

            endif;

        The false label corresponds to the code after the "then"
        section of the if statement (though not present, the "true"
        label would transfer control directly to the "then" portion
        of the if statement).

24: q.  Does HLA support classes and object oriented programming?
    a.  Yes.  It provides a very powerful class mechanism along with
        static class procedures, dynamic methods, and dynamic iterators.
        HLA support inheritence and many other features found in C++
        and Delphi.

25: q.  Do HLA procedure allow overloading?
    a.  Not directly.  However, you can easily use macros to provide
        any procedure overloading that you need?

26: q.  Does HLA support operator overloading?
    a.  Uh, no.  Assembly language in general does not support
        run-time arithmetic expressions (which is where operator
        overloading makes sense).  Hence the notion of operator
        overloading is foreign to HLA.

27: q.  Doesn't HLA's HLL statements make the language inefficient?
    a.  Not really.  First of all, keep in mind that you don't have
        to use them.  If you don't use them, they certainly won't
        affect the efficiency of your program  Second, keep in mind
        that most HLL control structures compile to a cmp, a
        conditional jump, and, perhaps, a jmp instruction.  Since
        this is exactly the type of code you'd probably write
        yourself, there is very little efficiency loss.

        Having said this, I should point out that anyone who
        approaches assembly language programming with a HLL mindset
        cannot expect to write super efficient programs.  In order
        to obtain the benefits of assembly language, you need to
        think in assembly language.  Using the HLL control structures
        relieves you of the need to think in assembly language.


---------------- HLA Standard Library Questions ---------------------

1:  q.  How to I write a procedure that converts a number to
        an ASCII string for output?
    a.  You don't.  Instead you should call one of the many
        Standard Library routines that will solve this problem
        for you.

2:  q.  What is the HLA Standard Library?
    a.  It is a set of procedures you can call in your HLA
        programs.  There are literally hundreds of routines
        you can call to accomplish many common tasks (for
        example, printing a number).

3:  q.  What library routines are available?
    a.  The list appears at the end of this document (it's long!).

4:  q.  What are the categories these routines fall into?
    a.  There are several categories, here's the current list
        (growing each week, so this is probably out of date):

            args-       Command line argument parsing.
            console-    Console window/smart terminal support routines.
            conv-       Numeric/string and other conversions.
            cset-       Character set functions.
            excepts-    Exception handling.
            hla-        Various constants, etc., for HLA compile-time
                        language support (e.g., DSELs).
            hll-        Macros to implement additional HLL statements.
            math-       Transcendental and logarithmic functions.
            memory-     Memory allocation and deallocation.
            misctypes-  Various miscellaneous data type declarations.
            patterns-   Pattern matching library (sorta like Snobol4/Icon).
            rand-       Random number generators and support routines.
            stdio-      Console and file I/O routines.
            strings-    String library.
            Tables-     Tables (associative array) library.
            win32-      Win32 API constants and declarations.
            x86-        Constants associated with Intel chips.





WIP (work in progress, more to come later, including the full routine
listing).

Re: Ada 95 based RTOS

[Robert Dewar]

In article <x7v7lfvt811.fsf@pogner.demon.co.uk>,
  Simon Wright <simon@pogner.demon.co.uk> wrote:
> IANAL but seems to me that if I were to base my code on the
> GNAT sources it would definitely come under the GPL. However,
> if I just use functionality provided by the GNAT sources,
> that's a different matter.

That's incorrect.

First, if you modify the GNAT sources for your own use, they
definitely do not need to be licensed to anyone but yourself,
and your modifications can be kept entirely to yourself under
whatever restrictions you like. It is only if you decide to
distribute the sources that they would be covered by the GPL
since otherwise your distribution of the modified sources
would violate the original copyright.

Second, if you merely write new modules using the same interface
as GNAT, then there is definitely no restriction. For instance
there is nothing to stop someone providing a proprietary
replacement for the GNAT runtime library.

As for TopLayer, I think the eventual intention is for them
to distribute what they do under the GPL or modified GPL, but
they are not yet at that point in their development as I
understand the situation. of course you have to check with them
to get the definitive story!

Robert Dewar
Ada Core Technologies


Sent via Deja.com http://www.deja.com/
Before you buy.

Re: Why should hackers love Ada. (Re: Ada 95 based RTOS)

[Larry Kilgallen]

In article <38B55928.8A0EAB06@quadruscorp.com>, "Marin D. Condic" <mcondic-nospam@quadruscorp.com> writes:
> Gary wrote:
>> I see this reference to ADA being good at bit twiddling, periodically.
>> Virtually all high-level languages provide facilities for bit twiddling.  Is
>> there something unique about ADA (I'm a non-ADA programmers, sorry).  Is this
>> a reference to a transfer function (other languages have this) or memory
>> aliasing tricks?
> 
> Well, I don't know what the rest of the world means by "bit twiddling"
> but I know what *I* mean when I say that. ;-)
> 
> You have all the facilities you need in Ada (Ada95 - Ada83 didn't do
> this well) to do shifting, masking & other manipulations of individual
> bits within words. If you've ever had to do interfacing to low level
> devices, hardware registers, I/O ports, etc., then you know that you
> can't always deal with data as an "abstraction" where you can allow the
> compiler to pick whatever representations it wants and manipulate things
> any way it likes. Often I have been up against time constraints where
> even if a high level method of solving the problem may work fine, we
> dipped into bit masks and logical operators because they degenerated to
> much more efficient code.
> 
> Ada95 lets you get at things like this when you need to. The difference
> between Ada and C on this issue is that with Ada it is a "last resort"
> whereas with C it is a "way of life". (Look at how lots of bindings to C
> stuff includes numeric constants for specifying options by or'ing
> together the constants. While Ada can do that, it isn't the usual
> idiom.)

I think a major advantage of Ada is that it lets the programmer deal
at a higher level for the main body of the program, while only the
interface description contains the specification that bits 2-4 are
treated as a numeric field for the unit number.  The compiler aids
and enforces adherence to that specification without requiring the
programmer to be constantly thinking about it and getting it right.

Re: Why should hackers love Ada. (Re: Ada 95 based RTOS)

[Ted Dennison]

In article
<Pine.A41.3.96-heb-2.07.1000224095942.88252E-100000@pluto.mscc.huji.ac.i
l>,
  Ehud Lamm <mslamm@mscc.huji.ac.il> wrote:

> Hacking evolved through time. Today, I think coding in assembly is
more
> the realm of what is known as 'Real Programmers" and not hackers.
> (Hope you are all familiar with the funny "Real programmers don't Eat
> Quiche" and its relatives)

If you're not, here are some from FOLDOC:
 Real Programmers Don't Use PASCAL -
http://www.instantweb.com/foldoc/foldoc.cgi?Real+Programmers+Don't+Use+P
ascal

(Oddly, has a farily positive mention of Ada)

 The Story of Mel, a Real Programmer -
http://www.instantweb.com/foldoc/foldoc.cgi?The+Story+of+Mel

Reading both of these lengthy but entertaining tales will give a very
good idea of what is meant by "Real Programmer".

--
T.E.D.

http://www.telepath.com/~dennison/Ted/TED.html


Sent via Deja.com http://www.deja.com/
Before you buy.

Re: Why should hackers love Ada. (Re: Ada 95 based RTOS)

[Ehud Lamm]

On Wed, 23 Feb 2000, Gautier wrote:

| In addition: understandable after 6 months,
|even with poor formatting!
|

But this takes all the fun from reading the source! Now every wannabe will
be able to read the source.

Ehud Lamm mslamm@mscc.huji.ac.il
http://purl.oclc.org/NET/ehudlamm <== My home on the web 
Check it out and subscribe to the E-List- for interesting essays and more!

Re: Why should hackers love Ada. (Re: Ada 95 based RTOS)

[Ehud Lamm]

On Wed, 23 Feb 2000, Marin D. Condic wrote:

|But I suppose those who would hang the moniker "hacker" upon themselves
|really want assembly language - only without the inconvenience of having
|to learn a new one every time new hardware comes out. Hence the
|popularity of things like C with hackers.
|

It is worth noticing that hackers also like VHLL, since they are
interesting to play with. Scheme is well liked (though APL isn't. So it is
tempting to see the "hacker attitude" as fashion?!)

Hacking evolved through time. Today, I think coding in assembly is more
the realm of what is known as 'Real Programmers" and not hackers.
(Hope you are all familiar with the funny "Real programmers don't Eat
Quiche" and its relatives)

Ehud Lamm mslamm@mscc.huji.ac.il
http://purl.oclc.org/NET/ehudlamm <== My home on the web 
Check it out and subscribe to the E-List- for interesting essays and more!

Re: Why should hackers love Ada. (Re: Ada 95 based RTOS)

[Marin D. Condic]

Gary wrote:
> I see this reference to ADA being good at bit twiddling, periodically.
> Virtually all high-level languages provide facilities for bit twiddling.  Is
> there something unique about ADA (I'm a non-ADA programmers, sorry).  Is this
> a reference to a transfer function (other languages have this) or memory
> aliasing tricks?

Well, I don't know what the rest of the world means by "bit twiddling"
but I know what *I* mean when I say that. ;-)

You have all the facilities you need in Ada (Ada95 - Ada83 didn't do
this well) to do shifting, masking & other manipulations of individual
bits within words. If you've ever had to do interfacing to low level
devices, hardware registers, I/O ports, etc., then you know that you
can't always deal with data as an "abstraction" where you can allow the
compiler to pick whatever representations it wants and manipulate things
any way it likes. Often I have been up against time constraints where
even if a high level method of solving the problem may work fine, we
dipped into bit masks and logical operators because they degenerated to
much more efficient code.

Ada95 lets you get at things like this when you need to. The difference
between Ada and C on this issue is that with Ada it is a "last resort"
whereas with C it is a "way of life". (Look at how lots of bindings to C
stuff includes numeric constants for specifying options by or'ing
together the constants. While Ada can do that, it isn't the usual
idiom.)

MDC
-- 
=============================================================
Marin David Condic   - Quadrus Corporation -   1.800.555.3393
1015-116 Atlantic Boulevard, Atlantic Beach, FL 32233
http://www.quadruscorp.com/
m c o n d i c @ q u a d r u s c o r p . c o m

***PLEASE REMOVE THE "-NOSPAM" PART OF MY RETURN ADDRESS***

Visit my web site at:  http://www.mcondic.com/

"Because that's where they keep the money."
    --  Willie Sutton when asked why he robbed banks. 
=============================================================

Re: Why should hackers love Ada. (Re: Ada 95 based RTOS)

[Mike Silva]

Gary Scott wrote in message <38B5C9E6.143A32D6@flash.net>...
>Larry Kilgallen wrote:
>
>> In article <38B55928.8A0EAB06@quadruscorp.com>, "Marin D. Condic"
<mcondic-nospam@quadruscorp.com> writes:
>> > Gary wrote:
>> >> I see this reference to ADA being good at bit twiddling, periodically.
>> >> Virtually all high-level languages provide facilities for bit
twiddling.  Is
>> >> there something unique about ADA (I'm a non-ADA programmers, sorry).
Is this
>> >> a reference to a transfer function (other languages have this) or
memory
>> >> aliasing tricks?
>> >
>> > Well, I don't know what the rest of the world means by "bit twiddling"
>> > but I know what *I* mean when I say that. ;-)
>> >
>> > You have all the facilities you need in Ada (Ada95 - Ada83 didn't do
>> > this well) to do shifting, masking & other manipulations of individual
>> > bits within words. If you've ever had to do interfacing to low level
>> > devices, hardware registers, I/O ports, etc., then you know that you
>> > can't always deal with data as an "abstraction" where you can allow the
>> > compiler to pick whatever representations it wants and manipulate
things
>> > any way it likes. Often I have been up against time constraints where
>> > even if a high level method of solving the problem may work fine, we
>> > dipped into bit masks and logical operators because they degenerated to
>> > much more efficient code.
>> >
>> > Ada95 lets you get at things like this when you need to. The difference
>> > between Ada and C on this issue is that with Ada it is a "last resort"
>> > whereas with C it is a "way of life". (Look at how lots of bindings to
C
>> > stuff includes numeric constants for specifying options by or'ing
>> > together the constants. While Ada can do that, it isn't the usual
>> > idiom.)
>>
>> I think a major advantage of Ada is that it lets the programmer deal
>> at a higher level for the main body of the program, while only the
>> interface description contains the specification that bits 2-4 are
>> treated as a numeric field for the unit number.  The compiler aids
>> and enforces adherence to that specification without requiring the
>> programmer to be constantly thinking about it and getting it right.
>
>This is a good feature, but many other languages have similar features
(some very old like Jovial and PL/1).
>In other languages, my experience is that you simply define
pack/unpack/scale routines and write the main
>executive and high-level functionality in a high-level fashion (possibly
OO) and simply invoke these low-level
>"reformat" routines at the top and bottom of the frame (or as-required).
Then again, I'm also used to being
>able to embed assembly to gain access to an interval timer or generate an
interrupt right into the high-level
>language code.


It seems that you are challenging the group to prove that Ada is somehow
"the best" at "bit-twiddling".  I suspect that the only claim that can be
made is that Ada has very good support for such things -- not only
bit-twiddling but also e.g. specification of data representations, tasking
and interrupt handling.  Ada is simply a very nice general purpose language
that has everything you need for cuddling up to the hardware.

Mike

Re: Why should hackers love Ada. (Re: Ada 95 based RTOS)

[Gary Scott]

Larry Kilgallen wrote:

> In article <38B55928.8A0EAB06@quadruscorp.com>, "Marin D. Condic" <mcondic-nospam@quadruscorp.com> writes:
> > Gary wrote:
> >> I see this reference to ADA being good at bit twiddling, periodically.
> >> Virtually all high-level languages provide facilities for bit twiddling.  Is
> >> there something unique about ADA (I'm a non-ADA programmers, sorry).  Is this
> >> a reference to a transfer function (other languages have this) or memory
> >> aliasing tricks?
> >
> > Well, I don't know what the rest of the world means by "bit twiddling"
> > but I know what *I* mean when I say that. ;-)
> >
> > You have all the facilities you need in Ada (Ada95 - Ada83 didn't do
> > this well) to do shifting, masking & other manipulations of individual
> > bits within words. If you've ever had to do interfacing to low level
> > devices, hardware registers, I/O ports, etc., then you know that you
> > can't always deal with data as an "abstraction" where you can allow the
> > compiler to pick whatever representations it wants and manipulate things
> > any way it likes. Often I have been up against time constraints where
> > even if a high level method of solving the problem may work fine, we
> > dipped into bit masks and logical operators because they degenerated to
> > much more efficient code.
> >
> > Ada95 lets you get at things like this when you need to. The difference
> > between Ada and C on this issue is that with Ada it is a "last resort"
> > whereas with C it is a "way of life". (Look at how lots of bindings to C
> > stuff includes numeric constants for specifying options by or'ing
> > together the constants. While Ada can do that, it isn't the usual
> > idiom.)
>
> I think a major advantage of Ada is that it lets the programmer deal
> at a higher level for the main body of the program, while only the
> interface description contains the specification that bits 2-4 are
> treated as a numeric field for the unit number.  The compiler aids
> and enforces adherence to that specification without requiring the
> programmer to be constantly thinking about it and getting it right.

This is a good feature, but many other languages have similar features (some very old like Jovial and PL/1).
In other languages, my experience is that you simply define pack/unpack/scale routines and write the main
executive and high-level functionality in a high-level fashion (possibly OO) and simply invoke these low-level
"reformat" routines at the top and bottom of the frame (or as-required).  Then again, I'm also used to being
able to embed assembly to gain access to an interval timer or generate an interrupt right into the high-level
language code.



--

Gary Scott
mailto:scottg@flash.net

mailto:webmaster@fortranlib.com
http://www.fortranlib.com

Re: Why should hackers love Ada. (Re: Ada 95 based RTOS)

[Gary]

"Marin D. Condic" wrote:

> Gary Scott wrote:
> > This is a good feature, but many other languages have similar features (some very old like Jovial and PL/1).
> > In other languages, my experience is that you simply define pack/unpack/scale routines and write the main
> > executive and high-level functionality in a high-level fashion (possibly OO) and simply invoke these low-level
> > "reformat" routines at the top and bottom of the frame (or as-required).  Then again, I'm also used to being
> > able to embed assembly to gain access to an interval timer or generate an interrupt right into the high-level
> > language code.
> >
> There are lots of languages that give you good control of the underlying
> representation of data and access to the hardware. Jovial was better
> than most in this respect. However, I think there is a difference
> between Ada and other languages in this respect. Ada tends towards
> encouraging encapsulation of the low-level features so that they exist
> in an isolated spot, whereas other languages treat access to low level
> features as the "normal" mode of writing code. For example, you mention
> embedded assembly. Ada will let you do that but you have to isolate it
> in a subprogram - you can't just stick assembler instructions anywhere
> you feel like.
>

This has quite a lot to do with programming style.  I can encapsulate/isolate "low-level" functions in almost any
language, but few languages restrict my choices.  I agree that encapsulation/isolation is a good thing in general
and I practice it for the most part, regardless of the language that I use (primarily for portability reasons).  I
prefer to have the freedom to make those types of decisions.  For some applications, it may be entirely appropriate
to generate an interrupt in a program main.

>
> MDC
> --
> =============================================================
> Marin David Condic   - Quadrus Corporation -   1.800.555.3393
> 1015-116 Atlantic Boulevard, Atlantic Beach, FL 32233
> http://www.quadruscorp.com/
> m c o n d i c @ q u a d r u s c o r p . c o m
>
> ***PLEASE REMOVE THE "-NOSPAM" PART OF MY RETURN ADDRESS***
>
> Visit my web site at:  http://www.mcondic.com/
>
> "Because that's where they keep the money."
>     --  Willie Sutton when asked why he robbed banks.
> =============================================================

Re: Ada 95 based RTOS

[Mike Silva]

(Tried to post this earlier but seems to have been bit-bucketed...)

Do you actually need the RTOS if you're using Ada?  Given the concurrency
support provided in Ada you may not need it.  Of course, the Ada
implementation you use will use some RTOS-like code "under the hood" to
provide the language concurrency features, but you may be able to do what
you want strictly in Ada -- depends on what you're trying to do.

I suspect the reason there aren't many (any?) RTOSes in Ada because, unlike
C/C++, there's no need for one to do tasking in Ada (yes it's there, but not
visible).

Mike

xaplos@my-deja.com wrote in message <88qli0$gvr$1@nnrp1.deja.com>...
>Thank you very much for the reference to RTEMS. I downloaded version 4
>only to find out that the source files are in C. I keep reading on
>several sites that there is a version of RTEMS written in Ada; however,
>I can't find it.
>
>It is my understanding that I can compile Ada source into object files
>with GNAT and link them with RTEMS which is written in C to run my
>applications on lets say an M68K. Because of the nature of the project
>I'm working on - master's thesis - I'd really like to be working with
>code from the same language - hence my desire to find the Ada version of
>RTEMS.

Re: Why should hackers love Ada. (Re: Ada 95 based RTOS)

[Marin D. Condic]

Gary Scott wrote:
> This is a good feature, but many other languages have similar features (some very old like Jovial and PL/1).
> In other languages, my experience is that you simply define pack/unpack/scale routines and write the main
> executive and high-level functionality in a high-level fashion (possibly OO) and simply invoke these low-level
> "reformat" routines at the top and bottom of the frame (or as-required).  Then again, I'm also used to being
> able to embed assembly to gain access to an interval timer or generate an interrupt right into the high-level
> language code.
> 
There are lots of languages that give you good control of the underlying
representation of data and access to the hardware. Jovial was better
than most in this respect. However, I think there is a difference
between Ada and other languages in this respect. Ada tends towards
encouraging encapsulation of the low-level features so that they exist
in an isolated spot, whereas other languages treat access to low level
features as the "normal" mode of writing code. For example, you mention
embedded assembly. Ada will let you do that but you have to isolate it
in a subprogram - you can't just stick assembler instructions anywhere
you feel like.

MDC
-- 
=============================================================
Marin David Condic   - Quadrus Corporation -   1.800.555.3393
1015-116 Atlantic Boulevard, Atlantic Beach, FL 32233
http://www.quadruscorp.com/
m c o n d i c @ q u a d r u s c o r p . c o m

***PLEASE REMOVE THE "-NOSPAM" PART OF MY RETURN ADDRESS***

Visit my web site at:  http://www.mcondic.com/

"Because that's where they keep the money."
    --  Willie Sutton when asked why he robbed banks. 
=============================================================

Re: Ada 95 based RTOS

[Scott Ingram]

Ted Dennison wrote:
> 
> In article <890ght$bih1@ftp.kvaerner.com>,
>   "Tarjei T. Jensen" <tarjei.jensen@kvaerner.com> wrote:
> >
> > If your read (and believe) what the Jargon file
> > (http://www.tuxedo.org/~esr/jargon/) writes about Ada then it is not
> 
> You shouldn't. This has come up before. ESR is not particularly Ada
> friendly, and his jargon file is mainly his feelings on the defnitions
> of things. He's a clever guy, but he doesn't know everything. So the
> stuff in the jargon file is often quite off the mark.
> 
> I much prefer to refer people to FOLDOC (
> http://foldoc.doc.ic.ac.uk/foldoc/mirrors.html ), which takes
> submissions from anyone. Its much more comprehensive, better maintained,
> and wittier.
> 
> --
> T.E.D.
> 
> http://www.telepath.com/~dennison/Ted/TED.html
> 
> Sent via Deja.com http://www.deja.com/
> Before you buy.

Also note the interesting Ada entry in the "Super Linux Encyclopedia" at
http://smalllinux.netpedia.net/links/ada.html.  Its well done, neutral,
and
provides links to all of our favorite sites.
-- 
Scott Ingram
Sonar Processing and Analysis Laboratory
Johns Hopkins University Applied Physics Laboratory

Re: Ada 95 based RTOS

[xaplos]

I'm an Ada newbie so I'm flying by the seat of my pants:-) I have worked
on several large projects in both C/C++ and Java, but have only recently
joined the Ada family (thanks to all for sending the RTEMS Ada sources).

My goal is to develop an open-source, Ada-based environment for wireless
devices - similar to the Palm OS. I'm planning to run it on the M68K
processor and imagine the Ada run-time environment must be embedded in
the ROM of the device to support the standard Ada packages; that way an
application engineer can program third party apps using the standard
packages in ROM rather than keeping another copy of the package for each
program that references it. I was thinking that rather than trying to
support the entire Ada run-time environment, I would use RTEMS or some
other Ada-based RTOS to support only the necessary features for this
type of OS and minimize overhead.

If I'm not making any sense, please correct me (this is the design goal
used by the Palm OS - reduce memory by not supporting the standard C
run-time library but rather the Palm OS API in ROM). Again, the
reasoning behind this type of thinking is from my knowledge of C/C++.

In article <UUAt4.1405$dw3.82979@news.wenet.net>,
  "Mike Silva" <mjsilva@jps.net> wrote:
> (Tried to post this earlier but seems to have been bit-bucketed...)
>
> Do you actually need the RTOS if you're using Ada?  Given the
concurrency
> support provided in Ada you may not need it.  Of course, the Ada
> implementation you use will use some RTOS-like code "under the hood"
to
> provide the language concurrency features, but you may be able to do
what
> you want strictly in Ada -- depends on what you're trying to do.
>
> I suspect the reason there aren't many (any?) RTOSes in Ada because,
unlike
> C/C++, there's no need for one to do tasking in Ada (yes it's there,
but not
> visible).
>
> Mike
>
> xaplos@my-deja.com wrote in message <88qli0$gvr$1@nnrp1.deja.com>...
> >Thank you very much for the reference to RTEMS. I downloaded version
4
> >only to find out that the source files are in C. I keep reading on
> >several sites that there is a version of RTEMS written in Ada;
however,
> >I can't find it.
> >
> >It is my understanding that I can compile Ada source into object
files
> >with GNAT and link them with RTEMS which is written in C to run my
> >applications on lets say an M68K. Because of the nature of the
project
> >I'm working on - master's thesis - I'd really like to be working with
> >code from the same language - hence my desire to find the Ada ver


Sent via Deja.com http://www.deja.com/
Before you buy.

Re: Why should hackers love Ada. (Re: Ada 95 based RTOS)

[Robert Dewar]

> > Gary wrote:
> >> I see this reference to ADA being good at bit twiddling,
periodically.
> >> Virtually all high-level languages provide facilities for
bit twiddling.

Sure, but the facilities in Ada are far more powerful, allow
more control, and most importantly, provide a much better level
of abstraction. For example, packed bit arrays are a powerful
feature missing from C. Sure you can program this yourself in
C, but it is messy, error prone, and results in ugly and
possibly inefficient code.


Sent via Deja.com http://www.deja.com/
Before you buy.

Re: Why should hackers love Ada. (Re: Ada 95 based RTOS)

[Gary Scott]

Mike Silva wrote:

> Gary Scott wrote in message <38B5C9E6.143A32D6@flash.net>...
> >Larry Kilgallen wrote:
> >
> >> In article <38B55928.8A0EAB06@quadruscorp.com>, "Marin D. Condic"
> <mcondic-nospam@quadruscorp.com> writes:
> >> > Gary wrote:
> >> >> I see this reference to ADA being good at bit twiddling, periodically.
> >> >> Virtually all high-level languages provide facilities for bit
> twiddling.  Is
> >> >> there something unique about ADA (I'm a non-ADA programmers, sorry).
> Is this
> >> >> a reference to a transfer function (other languages have this) or
> memory
> >> >> aliasing tricks?
> >> >
> >> > Well, I don't know what the rest of the world means by "bit twiddling"
> >> > but I know what *I* mean when I say that. ;-)
> >> >
> >> > You have all the facilities you need in Ada (Ada95 - Ada83 didn't do
> >> > this well) to do shifting, masking & other manipulations of individual
> >> > bits within words. If you've ever had to do interfacing to low level
> >> > devices, hardware registers, I/O ports, etc., then you know that you
> >> > can't always deal with data as an "abstraction" where you can allow the
> >> > compiler to pick whatever representations it wants and manipulate
> things
> >> > any way it likes. Often I have been up against time constraints where
> >> > even if a high level method of solving the problem may work fine, we
> >> > dipped into bit masks and logical operators because they degenerated to
> >> > much more efficient code.
> >> >
> >> > Ada95 lets you get at things like this when you need to. The difference
> >> > between Ada and C on this issue is that with Ada it is a "last resort"
> >> > whereas with C it is a "way of life". (Look at how lots of bindings to
> C
> >> > stuff includes numeric constants for specifying options by or'ing
> >> > together the constants. While Ada can do that, it isn't the usual
> >> > idiom.)
> >>
> >> I think a major advantage of Ada is that it lets the programmer deal
> >> at a higher level for the main body of the program, while only the
> >> interface description contains the specification that bits 2-4 are
> >> treated as a numeric field for the unit number.  The compiler aids
> >> and enforces adherence to that specification without requiring the
> >> programmer to be constantly thinking about it and getting it right.
> >
> >This is a good feature, but many other languages have similar features
> (some very old like Jovial and PL/1).
> >In other languages, my experience is that you simply define
> pack/unpack/scale routines and write the main
> >executive and high-level functionality in a high-level fashion (possibly
> OO) and simply invoke these low-level
> >"reformat" routines at the top and bottom of the frame (or as-required).
> Then again, I'm also used to being
> >able to embed assembly to gain access to an interval timer or generate an
> interrupt right into the high-level
> >language code.
>
> It seems that you are challenging the group to prove that Ada is somehow
> "the best" at "bit-twiddling".  I suspect that the only claim that can be
> made is that Ada has very good support for such things -- not only
> bit-twiddling but also e.g. specification of data representations, tasking
> and interrupt handling.  Ada is simply a very nice general purpose language
> that has everything you need for cuddling up to the hardware.

:-) I wasn't really challenging the group to prove Ada's worth, I'm just an
interested non-ADA programmer.  My company uses Ada 83 extensively and has had
significant difficulty meeting memory footprint and code execution performance
criteria.  I believe this to be mostly the result of poor management decisions
regarding forced use of OO in inappropriate ways (yes I know its Ada 83, not Ada
95).  I'm really just interested in understanding better the reasons for these
difficulties.

>
>
> Mike




--

Gary Scott
mailto:scottg@flash.net

mailto:webmaster@fortranlib.com
http://www.fortranlib.com

Re: Why should hackers love Ada. (Re: Ada 95 based RTOS)

[Gary Scott]

Robert Dewar wrote:

> > > Gary wrote:
> > >> I see this reference to ADA being good at bit twiddling,
> periodically.
> > >> Virtually all high-level languages provide facilities for
> bit twiddling.
>
> Sure, but the facilities in Ada are far more powerful, allow
> more control, and most importantly, provide a much better level
> of abstraction. For example, packed bit arrays are a powerful
> feature missing from C. Sure you can program this yourself in
> C, but it is messy, error prone, and results in ugly and
> possibly inefficient code.
>

C or C++ or both?  Fortran 95 has better facilities than C (and certainly better
syntax)...I do wish, however, that support for packed bit arrays was more
widespread.

>
> Sent via Deja.com http://www.deja.com/
> Before you buy.




--

Gary Scott
mailto:scottg@flash.net

mailto:webmaster@fortranlib.com
http://www.fortranlib.com

Re: Why should hackers love Ada. (Re: Ada 95 based RTOS)

[Mike Dimmick]

"Gary Scott" <scottg@flash.net> wrote in message
news:38B80EBA.721830@flash.net...
> Robert Dewar wrote:
>
> > > > Gary wrote:
> > > >> I see this reference to ADA being good at bit twiddling,
> > periodically.
> > > >> Virtually all high-level languages provide facilities for
> > bit twiddling.
> >
> > Sure, but the facilities in Ada are far more powerful, allow
> > more control, and most importantly, provide a much better level
> > of abstraction. For example, packed bit arrays are a powerful
> > feature missing from C. Sure you can program this yourself in
> > C, but it is messy, error prone, and results in ugly and
> > possibly inefficient code.
> >
>
> C or C++ or both?  Fortran 95 has better facilities than C (and
certainly better
> syntax)...I do wish, however, that support for packed bit arrays was
more
> widespread.

C.  C++ has the <bitvector> as part of the standard library (alright,
it's not part of the language, but it should be there on all
implementations of standard C++).

Unfortunately not all compilers are standards-compliant yet.  MSVC 6 is
close, but missing a few things; GCC (egcs) isn't quite there yet
either.  For example, egcs has only just added support for namespaces,
while some of the stream_iterators are broken on MS VC++.

As an example of this, try compiling some of Stroustrup's examples from
'The C++ Programming Language'.  I'd advise anyone considering flaming
C++ to look at this book to see what it's truly capable of, and how you
should now program in C++ given the standard language and its
library.[1]  The C++ standards committee stole quite a few ideas from
Ada95.

--
Mike Dimmick

[1] The first rule is, forget anything and everything you ever knew
about C.

Re: Why should hackers love Ada. (Re: Ada 95 based RTOS)

[Wil]

On Tue, 7 Mar 2000 20:37:37 -0000, "Mike Dimmick"
<mike@dimmick.demon.co.uk> wrote:

Thank God Stroustrup never borrowed tasks from Ada. Otherwise the 
standard never gets done.  On the other hand, C++ could go for 
another 10 years without a standard, and yet, enjoy a popularity
than (standardized) Ada can only dream about.
>As an example of this, try compiling some of Stroustrup's examples from
>'The C++ Programming Language'.  I'd advise anyone considering flaming
>C++ to look at this book to see what it's truly capable of, and how you
>should now program in C++ given the standard language and its
>library.[1]  The C++ standards committee stole quite a few ideas from
>Ada95.
>
>--
>Mike Dimmick
I can't. I am typing this from an OS written in C ! Will that Ada OS
ever get done, or is it just a hoax?

>[1] The first rule is, forget anything and everything you ever knew
>about C.
>
Will

Ada OS again Re: Why should hackers love Ada. (Re: Ada 95 based RTOS)

[David Starner]

On Fri, 10 Mar 2000 01:52:42 GMT, Wil <wv@fiam.net> wrote:
>I can't. I am typing this from an OS written in C ! Will that Ada OS
>ever get done, or is it just a hoax?

How long do you think it takes to write an OS? Especially when you're
designing it from scratch, and try and blaze a new path. (Personally,
I think it's never going to work if they continue to be as iconoclastic
as they are, but it's far to early to say.)

-- 
David Starner - dstarner98@aasaa.ofe.org
Only a nerd would worry about wrong parentheses with
square brackets. But that's what mathematicians are.
   -- Dr. Burchard, math professor at OSU

Re: Why should hackers love Ada. (Re: Ada 95 based RTOS)

[David Botton]

You may want to join the new mail list for AdaOS and see how things are
going.

Send the word subscribe in the body to AdaOS-list-request@adapower.com

David Botton

Wil wrote in message <38c85476.1996324@news.fiam.net>...
>Will that Ada OS
>ever get done, or is it just a hoax?