[nickpsecurity]

This advice reflects what I've seen in safety-critical field reading on all kinds of deployments. This plus other comments to use simplest microcontrollers with tiny RTOS or no OS using simplified software. Good advice and good alias.

[tclmeelmo]

Thanks and thanks. To further bloviate, Tcl is my not-so-secret weapon. I first used it when doing exploratory work with some embedded one-off instruments and it made an impression because those doohickies are still running strong to this day, well beyond the design goal. They had sensors that were communicating over a serial console: Tcl made interfacing quick and painless, and a control GUI in Tk practically built itself. It's robust and a known quantity (flaws and all). There's also some level of je ne sais quoi where, like Lisp, I don't feel like I will paint myself into a corner: need more performance? drop down to C. language is limiting? make a better DSL. So I guess I'm either a fan or delusional (likely, both).

I don't personally know of anyone in medical using it, but your comment about no OS does prod me to say that I have wondered if running Forth on bare metal for medical is viable and/or desirable on a greenfield project. I'm not saying I would do it, but I would happily cheer on someone else. (OP, don't do this, I'm delusional)

And OP, I really hope that my wall of text won't be discouraging in any way. Personally, I found that documentation is (a la Homer Simpson) the cause of, and solution to, all of life's problems in a regulated environment. If you master that, document honestly and eagerly, it's downhill from there and life will be good.

[nickpsecurity]

I never thought of Tcl to be used in safety- or security-critical systems. It's certainly simple and easy to use. We played with it for agent-oriented programming back in the day. Had serious, design-level issues for security and was harder to parse than some others (eg LISP's).

Rather than just a critique, I'm curious where and how you use it with what benefits it brings you? I could certainly see it in UI or untrusted parts. Maybe also during development in a way that auto-generates C or something that runs in production.

[tclmeelmo]

I only use it like you guessed (and what I think it's best/appropriate for): gluing things together, embedded scripting, and Tk on internal tools/gizmos and early prototypes. I wasn't clear earlier, sorry.

To be perfectly fair, on the decision matrix Tcl gets a helpful boost due to my own familiarity with it and playing nice with C; if a butterfly had flapped it's wings just a little bit differently or I was starting out today I would probably be using something else. Probably Java. Ada would be great, but the lack of ecosystem diversity makes me apprehensive.

[nickpsecurity]

Gotcha. Look into REBOL/RED while you're at it. RED is a REBOL clone/modification for system programming. They're LISP like advantages without the parenthesis and having small footprint. RED is already used in one OS project. I keep thinking of modifying it for system use. People keep telling me to check out Nim as it's like Pascal and Python combined with extra safety, macros, and C code generation.

So, there you have it: REBOL, RED, and Nim. Maybe Ivory language from Galois, too, but you need to know Haskell for that.

[tclmeelmo]

I remember playing around with REBOL a long time ago and it seemed useful and practical, but for reasons long forgotten I never used it. Maybe licensing? RED does look cool and I hadn't heard of it before, thanks for the tip.

Don't have any experience with Nim, but I share your interest for the same reasons. Haskell and I don't get along, maybe I'm too old and set in my ways?

Did you catch the link to/discussion of Little shared on here a few days ago? It might be of interest. https://news.ycombinator.com/item?id=11530097

[nickpsecurity]

Me too on Haskell. Mainly plan to try other two. Saw Little but didn't really get it past adoption. Then, your comment led me to the Why page which told me that was exactly the point. Along with programming in the large support. Funnier when I found out the boss wrote that.

I'd say it's not a good language to go with today for same reasons I'd say Tcl isn't. It's an interesting improvement especially to get better syntax with legacy compatibility with field-proven, TCL modules. And TK is still the shit for portable, easy-to-build GUI's. A TCL shop should definitely experiment with it and maybe incrementally upgrade their code. I think I'd be fine with a more typed, efficient, and fixed version of Tcl for some apps. Especially a command shell replacement or prototyping system.

Just not production unless it's non-critical like what you use it for. I don't even use it to glue to critical things as the glue is part of the TCB to a degree. Gotta find close-to-metal, abstract, typed, efficient, and macro'd stuff to replace it. At least we have contenders.

[blacksqr]

Rosea (http://chiselapp.com/user/mangoa01/repository/mrtools/wiki?n...) is a tcl-based tool designed specifically for embedded medical applications where provable quality is critical. I think it deserves more attention.

[tclmeelmo]

This is really interesting. Do you know of anyone using it in production?

[blacksqr]

The author works for a custom embedded code shop, and I believe has been using it and its antecedents for years for his customers. He's on my short list of personal coding heroes.