Modula-2 Developer ?

Question

Guess no new project is implemented in languages like Modula, Ada , Oberon .. anymore (right?). But still there are legacy systems floating around, popping out here and there looking for their creators. They cant find them because they might be retired sitting at a beach somewhere enjoying themselves.

Serious:
1) I am wondering if there are still active (experienced) Modula programmers around ?
2) Anyone experience with porting Modula code to a new hardware generation ?
3) Does anyone know about a tool that can re-engineer, means map Procedures and Mod-files in a graphical way. These tools are available for eg. C programs.

Sure, Modula Syntax is not that breathtaking in comparison to todays .net and Java API's with 1000's of methods, but if someone drop about 100.000 lines of almost undocumented sourcode at you (nicely mixed with some 8000 lines assembler), you better know if you better reject it. I have this request and I am very resistant. (Option: port and keep modula source or migrate to other language in 9 months!)

For the interested folks: Found a Modula IDE amongst others here: http://www.excelsior-usa.com/xdsx86win.html

cheers

Answer 1

I myself don't know much of Modula, however I worked at a research center in Brazil that had a packet switching network project (Compac) that was entirely created in Modula-2. If I'm not mistaken they even developed the compiler/linker themselves. Since I don't feel at liberty to point you to specific persons, I would suggest you do a google search for "compac" and "cpqd" and I can pretty much guarantee you will find names of people involved in it. It should come as no surprise that references to it are quite old, from late 80's.

Answer 2

1) I am wondering if there are still active (experienced) Modula programmers around ?

Yes, I'm one. But I already have a job :-)

2) Anyone experience with porting Modula code to a new hardware generation ?

Not clear if you meant porting code or porting a compiler. Porting Wirth's Modula-2 compiler (or Oberon compiler) should be easy. Ada and Modula-3 are another story.

3) Does anyone know about a tool that can re-engineer, means map Procedures and Mod-files in a graphical way. These tools are available for eg. C programs.

I don't understand the question. If you are looking to visualize the import graph of a Modula-2 program, you could easily write something to emit dot. Visualizing call graphs is another story.

Here's my bottom line on Modula-2 and Oberon:

1. Any C programmer worth his or her salt can quickly learn enough Modula-2 to maintain a large legacy application. Oberon's another story; its model of exported names and type extension is not like the object models found in other OO languages.

2. Wirth's genius as a language designer was to make things easy for the person writing the compiler. So if you need tools, any good compiler writer can produce them. Wirth's compiler should be available and easy to port.

Ada does not deserve to be mentioned in the same breath with Modula-2 and Oberon.

Answer 3

1) I am wondering if there are still active (experienced) Modula programmers around ?

There are plenty of them, but you have to do a bit of web search to find them. If you search for "Curriculum Vitae" (or "Resume") and "Modula-2" there should be plenty of hits. Also, anybody who has experience in Oberon, Pascal or Delphi will be able to handle Modula-2.

Also there are active Modula-2 projects, most notably:

• GNU Modula-2 at http://www.nongnu.org/gm2
• Modula2JCC at http://code.google.com/p/modula2jcc
• Objective Modula-2 at http://objective.modula2.net
• Modulipse at http://modulipse.sourceforge.net
• Schwarzer Kaffee http://sourceforge.net/projects/schwarzerkaffee

2) Anyone experience with porting Modula code to a new hardware generation ?

Ask on the GNU Modula-2 mailing list. Many GNU Modula-2 users have Modula-2 code from 16-bit DOS systems they like to port to modern platforms. The GNU Modula-2 website lists this as one important motivation for GM2. The GM2 mailing list is at:

• http://lists.nongnu.org/mailman/listinfo/gm2

There is also the Modula-2 Usenet news group, you can reach it via the Google interface at

• http://groups.google.com/group/comp.lang.modula2

Last but not least, there is a Modula-2 IRC channel at Freenode

• irc://irc.freenode.net/#modula-2

3) How to assess 100.000 lines of Modula-2 source code

"if someone drop about 100.000 lines of almost undocumented sourcode at you (nicely mixed with some 8000 lines assembler), you better know if you better reject it. I have this request and I am very resistant. (Option: port and keep modula source or migrate to other language in 9 months!)"

You may want to contact Rick Sutcliffe, a well known Modula-2 scholar and book author who is also the maintainer of the Modula-2 FAQ in which he states that he does get hired to do consulting work for assessing Modula-2 source code in company take-over situations. It seems to me that your situation might be similar enough to justify hiring an expert to establish the value of the software that is offered to you.

• The Modula-2 FAQ is at http://faq.modula2.net

Answer 4

Modula-2 is architecturally not that dissimilar to C. A programmer familiar with C should have little trouble figuring out Modula-2. Given that your application has a significant body of assembler code then you will need someone with low-level skills anyway.

IIRC Modula-2's grammar is LL(1) or nearly so, so writing a parser to generate call graphs for a Modula-2 code base is not beyond the wit of man. Graphviz is your friend if you want a quick and easy way of visualising the call graphs. Again, this suggests that you're up for employing a 'real programmer' to do the porting work.

If you need a reasonably viable Modula-2 compiler, you could look at the Amsterdam Compiler Kit which does have a competent Modula-2 compiler that can target a wide variety of platforms, although it doesn't support Win32 IIRC.

I would suggest that documenting and porting the existing Modula-2 code base is probably easier than attempting to re-write it in C. However, if you need to move to a different processor architecture then you will have to re-write the assembly language bits anyway. This does rather change the value proposition of porting.

If it is you doing the porting then you might consider doing it in two steps.

1. Arrange with the customer to do a utility to generate the call graph and give them a feasibility study recommending what to do and some estimate of the scope.

2. Do the port, either porting the code base or re-writing it. Bear in mind that you may not need a low level language for the entire code base if you're running it on a modern computer. You may be able to do it in a mixture of (say) Python and C with less effort than would have been needed for a rewrite purely in C.

Answer 5

Ada is still an very active language. I use it in my own research since 1995 and in my lectures since last year at a university.