Re: Good practical language and OS agnostic text?

glen herrmannsfeldt <gah@nospam.ugcs.caltech.edu> wrote:


> One Wirth language that you might find interesting is PL/360.
>
> PL/360 looks like a high-level language but works like assembly
> language. As an example (which I am remembering from 40 years ago)


I have the doc and compiler code, everything was released into the
public domain. It's so close to assembler I didn't consider it might
be a good way to learn to write a compiler but maybe it is. A 10
second look shows it's pretty heavily abstracted. I will have to spend
more time on it but it may be more a tribute to the traditional Wirth
terseness than something to learn from, at least without the professor
around to ask questions of.


> But I don't understand your refusal to use the tools that are
> available.


As I said they're not available on my target platform.


> FLEX and BISON are freely available, you can't complain that they cost too
> much.


True but irrelevant!


> You can run them on a freely available OS (Linux, FreeBSD, Solaris, etc.)
> on machines that you can find for very low prices, or often enough given
> away.


Ok but those aren't my targets. I'm not interested in using those for this
project, as I said. And I would really like to understand what I am doing
and the way I have always done that is to write my own code. Why is that
upsetting (hard to understand, etc.) to you? I haven't mentioned the cost of
anything, I'm not sure where you are coming from here.


> The nice thing about the tools is that you can get something running
> fairly fast, and without needing to get too deep into the math. You
> can go as deep or shallow into the innards of FLEX and BISON as you
> want. One project that should be about right for one person, and
> without a lot of math, is rewriting FLEX and BISON to generate code in
> another language, such as PL/I.


It would be nice to "get something running fairly fast" but if I do that
depending on other pieces I don't understand it doesn't really help me. I
want to learn as much as I can doing this.


> [PL/360 was a great little language, but the source code to the
> compiler was apparently lost. -John]


I believe Jay Maynard is hosting several PL/360 packages. AFAIK they are
complete.
[If so, they'd be a good place to start. It's basically an assembler with
Algol syntax, so it has a real parser. -John]

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