Hi Tom,

Your situation sounds somewhat familiar, and you may be interested to know what we decided to do. The company SARC has been using Extended Pascal since the ’80s, with currently roughly half a million LOC in production. We have been using Prospero Extended Pascal, a compiler that has disappeared from the market a decade ago.  Migrating to gpc would have been an option technically, but strategically not sustainable due to weak vital signs. Therefore we decided to port all of our code to either Free Pascal, Ada or D. You can read about the selection process here[1]. I ended up developing a transcompiler to help automating the conversion of our Pascal code to D[2]. The status of that project is that we currently have some 40+ modules translated and test programs are running. Have a look at the video of my report at DConf last month[3].

I am not sure whether porting your code is worthwhile, you may be best off with installing a virtual machine on your Mac with an OS where gpc is still working, and run your software off of that. But there is no question in my mind that porting is the only option if a long productive future is important. You may be able to leverage much of the work that we have done, but it certainly is not a one-click solution.

The syntax of D is different from Pascal, it is more like C. But unlike C, D shares many of the traits of Pascal, like array bounds checking and nested functions. The language is powerful and versatile. The D community is not large but active. D is used in bioinformatics already[4,5].

Let me know if you want to know more.


[1] https://dlang.org/blog/2018/06/20/how-an-engineering-company-chose-to-migrate-to-d/
[2] https://dlang.org/
[3] https://youtu.be/HvunD0ZJqiA
[4] https://youtu.be/Nf6a8Fd7STY
[5] https://wiki.dlang.org/Bioinformatics_Libraries 

Bastiaan Veelo, PhD

SARC B.V. www.sarc.nl
Brinklaan 109 A II
1404 GA Bussum, Netherlands
Phone: +31(0)85 0409040
Phone direct: +31(0)85 0409051