Som VS crosstalk

> Smalltalkish

Have a look at the SOM dialect which is successfully used in education: http://som-st.github.io/

Here is an implementation in C++ which runs on LuaJIT: https://github.com/rochus-keller/Som/

> unfortunately out of print book Smalltalk 80: the language and its implementation is commonly recommended

I assume you know this link: http://stephane.ducasse.free.fr/FreeBooks/BlueBook/Bluebook....

Here is an implementation in C++ and Lua: https://github.com/rochus-keller/Smalltalk

- https://github.com/rochus-keller/Smalltalk/ Parser, code model, interpreter and navigable browser for the original Xerox Smalltalk-80 v2 sources and virtual image file

- https://github.com/rochus-keller/Som/ Parser, code model, navigable browser and VM for the SOM Smalltalk dialect

- https://github.com/rochus-keller/Simula A Simula 67 parser written in C++ and Qt

> do you regret those endeavours?

No, not in any way; the projects were very entertaining and gave me interesting insights.

If your DSL is statically typed then I recommend that you have a look at the Mono CLR; it's compatible with the ECMA-335 standard and the IR (CIL) is well documented, even with secondary literature.

If your DSL is dynamically typed I recommend LuaJIT; the bytecode is lean and documented (not as good as CIL though). LuaJIT also works well with statically typed languages, but Mono is faster in the latter case. Even if it was originally built for Lua any compiler can generate LuaJIT bytecode.

Both approaches are lean (Mono about 8 MB, LuaJIT about 1 MB), general purpose, available on many platforms and work well (see e.g. https://github.com/rochus-keller/Oberon/ and https://github.com/rochus-keller/Som/).

At the latest when you run a benchmark suite like Are-we-fast-yet; here are some measurment results: http://software.rochus-keller.info/are-we-fast-yet_crystal_lua_node_som_pharo_i386_results_2020-12-29.pdf. See also https://github.com/rochus-keller/Som/ and https://github.com/rochus-keller/Smalltalk.

LuaJIT is well suited as a backend/runtime environment for custom languages; I did it several times (see e.g. https://github.com/rochus-keller/Smalltalk, https://github.com/rochus-keller/Som/, https://github.com/rochus-keller/Oberon/). I also implemented a bit of infrastructure to ease the reuse: https://github.com/rochus-keller/LjTools. LuaJIT has some limitations though; if you require closures you have to know that the corresponding LuaJIT FNEW bytecode is not yet supported by the JIT, i.e. switches to the interpreter; as a work-around I implemented my own closures; LuaJIT also doesn't support multi-threading, but co-routines; and there is no debugger, and the infrastructure to implement one has limitations (i.e. performance is low when running to breakpoints). For most of my projects this was no issue. Recently I switched to CIL/Mono for my Oberon+ implementation which was a good move. But still I consider LuaJIT a good choice if you can cope with the mentioned limitations. The major advantage of LuaJIT is the small footprint and impressive performance for dynamic languages.

One option is to leverage someone else's JIT: you could, for example, rewrite the interpreter to transpile to Lua source, which is then run in LuaJIT. There's a Smalltalk dialect which does this successfully; the Lua version runs in 1/12th the time of the C interpreted version. https://github.com/rochus-keller/Som You can use LuaJIT's FFI to call back into the Stunt server, or else just rewrite it completely in Lua --- large parts of the Stunt server will just go away in a native Lua implementation (e.g. the object database is just a table). Javascript would be another candidate for this.

This is a completely different kind of measurement; unfortunately this is not clear enough from my Readme. I wanted to find out, how well my naive Bluebook interpreter performs on LuaJIT (using my virtual meta tracing approach) compared to Cog, which is a dedicatd Smalltalk VM optimized with whatever genious approaches over two decades (or even longer considering the long experience record by Elliot). This experiment continues in https://github.com/rochus-keller/Som, because I didn't want to modify the original Smalltalk image. I found that my naive LuaJIT based approach is about factor seven behind the highly optimized Cog/Spur, and further improvements would require similar optimization tricks as in the latter.

I don't know why this popped up again now, but it's nice to see that some people are still interested in this little Smalltalk 80 system (I'm the author, happy to answer your questions...).

Code at https://github.com/michaelengel/crosstalk

Your concept looks nice, it reminds me a bit of the Lisperati: https://www.hackster.io/news/the-lisperati1000-is-a-cyberdec...

So, did you consider Lisp or maybe Smalltalk? Plan 9 or Inferno might also be options.

Plan 9 comes in different variants, the "classic" one (with a Raspberry Pi port by Richard Miller) or 9front, an Inferno porting tutorial can be found at https://github.com/yshurik/inferno-rpi

Lisp and Smalltalk can run with or without Linux underneath, e.g. on the Raspberry Pi.

Bare-metal Lisp is available with interim: http://interim-os.com

Finally, bare-metal Smalltalk is available in my crosstalk system: https://github.com/michaelengel/crosstalk

Of course, Lisp and Smalltalk can also run hosted under Linux, e.g. using Squeak (https://squeak.org), Pharo (https://pharo.org) or InterLisp (https://github.com/Interlisp/medley).

Or - a crazy idea - build an emacs-only machine. That would be fun! :)

Author here - this xv6 port to the D1 (based on the riscv64 xv6 version developed at MIT) is an experimentation vehicle for me and my students since working with qemu alone can be a bit boring and it's easier to test some feature in a tiny OS. Of course, it's also fun to work on it...

"...won't be big and professional like gnu." :)

Based on the experiences with xv6, we are also working on porting some other non-mainstream systems to RISC-V hardware, including Plan 9, Inferno, Oberon, Smalltalk-80 (see my Raspberry Pi bare metal ARM version at https://github.com/michaelengel/crosstalk) and the f9 microkernel.

If you have any questions about the xv6 port just ask.

Shameless plug - I'm looking for a PhD student to work on OS/compiler/architecture-related topics in my research group here at Bamberg University (in the northern part of Bavaria in Germany).

If you know someone who might be interested, please let them know...

What if those already-used tools weren't as-good for writing Smalltalk programs?

----

> … its own OS and GUI.

Well there are examples of bare metal Smalltalk (I'm guessing we could say the same of Java?)

    https://github.com/michaelengel/crosstalk

Well, you can run a bare metal Smalltalk-80 on the Raspberry Pi.

https://github.com/michaelengel/crosstalk

- NetBSD (https://wiki.netbsd.org/ports/evbarm/raspberry_pi/)

- FreeBSD (https://wiki.freebsd.org/arm/Raspberry%20Pi)

- Interim Lisp OS (http://interim-os.com - this runs on Raspi 2 only, so porting to the ARM v6 in the Raspi 1 would be a nice project) - btw., this is a project by Lukas Hartmann, who is also the creator of the open MNT Reform ARM laptop (https://mntre.com)

- (shameless plug) my bare metal "crosstalk" Smalltalk-80 (https://github.com/michaelengel/crosstalk)

I'm pretty sure this list isn't complete...

Some operating systems are not supported at the moment:

- OpenBSD only seems to support the Aarch64-based models 3 and 4

- Haiku seems to be looking for a maintainer for the Raspberry port