Request for Community Feedback on g-code++ (sterp) Integration with LinuxCNC

Hi everyone! I’ve recently been working on integrating g-code++ (a lightweight g-code interpreter inspired by the rs274ngc NIST g-code specification) into the LinuxCNC ecosystem. Before I submit a pull request, I’d like to get some community feedback so as to ensure that it fits well and is aligned with the project's direction.

Link to my original repo:  github.com/s-mv/gcode-plus-plus
Link to the LinuxCNC fork:  github.com/s-mv/linuxcnc/tree/s-mv/sterp (s-mv/sterp branch)
Demo video: 

What I’ve Done

• Integrated g-code++ into the LinuxCNC environment.
• Verified it works for 3-axis machines on LinuxCNC.
• Documented the integration process and architecture.
• Set up an ANTLR4-based parser for g-code interpretation.

Key features

• Control flow: Support for

  while

  loops,

  for

  loops,

  if

  statements, imports,

  continue

  , and

  break.

• g-code compatibility: Supports standard G-codes like G0, G1, G2, G3, G20, G21, G54, M3, M4, etc.

Feedback would be greatly appreciated, especially from people who have experience using g-code interpreters with LinuxCNC or have experience maintaining/debugging the project. Eager to make this integration as frictionless as possible so that it meets the needs of the community. Thanks in advance, and I’m looking forward to hearing your thoughts!

Best regards,
s-mv (Shreerang Vaidya)

Please tell us the advantages of gcode++

Right now gcode++ extends g-code by introducing for loops, while/do-while loops, as well as imports (currently working on test cases for the same for the latest LinuxCNC release).

The inclusion of these control structures and import statements could greatly improve readability and code reusability.

It also ships with an in-house REPL for dry-running programs that can be used outside of LinuxCNC and has richer logging - I intend to add a simple debugger to it possibly in the future.

Thanks a lot for reaching out!

Yes, in the current fork, it lives under src/emc/sterp as a plug-in interpreter.
In fact, I modeled it after studying how canterp works.

I understand that it might not gain much traction.

I'd love to maintain and extend the project as long as life permits me! Currently, I’m just an undergraduate, so I can’t promise a fixed 20-year roadmap just yet, but I've built sterp/gcode++ with maintainability in mind.
I might also extend it in the near future and add more preliminary unit tests.

What do you mean "imports" ?
I would think that a more modern approach to parsing could be a good thing to get more people interested in working on the code.

Chris

In the source i see you how you handle expressions.

I shoukd use a lib like: mu parser to handle expressions. 
This also handles and updates gcode variables for you. 

It wont run (nested) while loops. This while loop algo you can design yourself.

in future i love to see gcode dialect parsing,
given a json config file.

Then hopely the interpreter is also able to read fanuc and kuka robot language and produce the motion outputs for it. An extended version off straight_feed xyz...
would look like straigt_feed j1 j2 ....

Mu parser example

Hello Hello! Good morning to everyone!
Today I bring a thing from my treasure box. Reading this post i remember about 5 years i made my own robot (somewhere deep down, buried in this forum there are pictures and videos of it working..). So i said why not publishing the parser here!
Here it goes:
Basically i have been using tons of different robot brand:
FANUC, KUKA, YASKAWA (MOTOMAN), ABB, COMAU, CHINESE ONES (curiously lcnc based with jerk controlled tp), CHINESE ONES WITH KEBA CONTROLLER, etc.
The one i like the most is KUKA followed closely by ABB, both similar to pascal so i grab the manual and my experience in writing parsers and wrote (almost) the whole kuka KRL and made it compatible with linuxcnc interp plugin system.
it is named krlInterp

it consist in two parts:
ANTLR v4 parser, sources in c++ needs to be generated
krlInterpreter, just compile with linuxcnc source code (honestly i dont remember if some small modifications have to be made in linuxcnc src)

Links attached:
KRL ANTLR PARSER    and
KRL INTERPRETER

Any doubts, here i am!
Best regrads
​​​​​​​Franco