Quite a few years ago, I was looking for a way to program microcontrollers via an onboard interpreted language, and happened on the picol code. I still have my version somewhere. It was delightfully straightforward and easy for an amateur to modify. So I first got it to compile on a Teensy, then added a REPL, floating point, and a few functions to do things like flip the GPIO bits and read the ADC.
Today of course there are things like CircuitPython, and I enjoy using it too, but it's such a beast that it's really impenetrable for someone at my skill level if I want to add low level functions.
Thanks for your comment! Maybe it's time for picol2.c, same amount of lines of code, but floats and [expr]. I'm going to use a few hours today to get there. Such small changes would make it more practical for real use cases where one wants to retain understandability.
Yes. His work is really inspiring, eg. the text editor less than 1000 lines, tiny language in less than 1000 lines etc. When I read this on HN, I converted his text editor to my hobby programming language [1] (330 lines), and then wrote a chess engine with terminal UI [2] (400 lines), Tetris clone [3] in 140 lines. I also have a QR code generator and parser [4] (700 lines, still in Java only), a PDF generator (200 lines), and now also a tiny programming language [5].
best thing about TCL is easy syntax and that everything is a string :) Unique and simple and easy language with very slow changes.
Something like Python in good old days of 2.x before young internet javasceipt devs started pouring A LOT of new features to the language (feature creep).
Nowadays Python is so complex and flooded with ex C, C++, Java, JavaScript, Haskell programmers adding so many features, so fast that it's impossible to follow and understand them :(
Languages should not evolve on that rate. No time to master it :(
Tcl has stopped being everything a string with the release of Tcl 8.0 and bytecode engine.
> In earlier versions of Tcl, strings were used as a universal representation; in Tcl 8.0 strings are replaced with Tcl_Obj structures ("objects") that can hold both a string value and an internal form such as a binary integer or compiled bytecodes.
I remember this quite well, because as part of the core team tasked with writing native C extensions, the migration to Tcl 8 had quite an impact on our code.
I learned Python with version 1.6, and have a few O'Reilley books proving the point the language wasn't really that simple, those that never bothered reading the reference manuals end-to-end though it was.
There have always been attempts at caching non-string values in Tcl for performance gains, but the semantics are the same. The value’s types are whatever the operator requires and an error when not compatible. If, internally, $x is an integer, and you pass it to a string function, well, $x gets temporarily turned into a string. Dynamic with “weak” types.
There's certainly something to be said for stable, uncomplicated and minimalist tooling that wont evolve out from under you and leave you with something that won't just-work five years from now.
I guess that's why Tcl is so popular in the EDA arena. I can stick some custom JTAG tooling in a Cyclone II design and talk to it by Tcl-scripting the 15-year-old software - and be confident that the same code (both in the FPGA and on the host computer) would work with the latest software and a current device.
Having said that, Tcl's not entirely free of compatibility and fragmentation frustrations: I sometimes wish that OpenOCD used full-fat Tcl rather than JimTcl, just so that I could make use of Tk. Being able to plot a histogram of data collected from the FPGA or make clickable buttons to trigger events is very useful.
> Living proof that languages doesn't need forced types.
The opposite surely? TCL is practically dead, and only lingers on in the EDA industry (which has zero taste). Virtually every successful language today has at least a few different basic types for numbers, arrays, strings, maps and so on.
TCL's typicing discipline comes from shell languages and awk, which are decidedly not dead. The overwhelming majority of programmers have less than no taste, so language usage rates in general don't really mean much.
It depends on the use case. For instance you open a socket, write there any value you have without serialization, read it in the other side, data transfer done.
The convenience of not having to marshal data over a network is certainly a use case. But I'll admit that two of the worst programs I ever saw were written in Perl and TCL. Somehow just a big jumble of inscrutable regexes.
When "everything is a string" then you have no choice but to literally treat everything as a string. Painful. Very cool project though.
It's only the interface that is of a string. An array is a list of strings with space between, but only for the programmer. The runtime is free to use an actual array.
I remember we had users at a chip foundry who were super deep into TCL. Is it still used anywhere else? Would you use it for a new project if you for instance already knew Python or Lua?
Antirez (the author of this interpreter) uses it for the Redis test suite.
Personally, I know Lua and Python very well but I still used TCL a few years ago for something very specific: using ODBC on Windows. I gave more details on the Lua mailing list here: http://lua-users.org/lists/lua-l/2021-01/msg00067.html
That was interesting to read. So in your case it came down to ecosystem depth, especially on Windows - where there was a TCL solution to talk ODBC, but the equivalent Lua functionality had issues on Windows.
Tcl's first "release" was in 1988 and Magic was released in 1984, but it seems like John Ousterhout then wrote Tcl to have a common interface across tools [https://web.stanford.edu/~ouster/cgi-bin/tclHistory.php]. It still is a big thing in EDA, because (in theory) it lets a chip designer run their designs by tools from different vendors
Tcl/Tk to this day is the best tool to make GUI frontends for CLI applications. Besides that, in the past I used it in production for intranet database entry applications. It has since been replaced by Flask. In my opinion the higher complexity of the Flask version is no way justified and we should have kept the much simpler ~2k LOC Tcl/Tk solution.
Tk's GUI object model is sitting at a reasonable maxima between trivial to make use of vs. triggering the events necessary to make the GUI active.
Small example. You want a button on your GUI that triggers a procedure called "process" when it is clicked, this is the code you need (if you are fine with the remaining defaults) (and assuming you used 'pack' as the geometry manager):
button .process -text "Process Entries" -command process
pack .process -side top
And a fully active GUI button will now appear at the bottom of your Tk window, with a label of "Process Entries" and when you click it, a Tcl procedure named "process" will be executed.
CLI applications typically read text from stdin and write text to stdout. The tcl model of "everything is a string" makes exactly the right abstraction to create GUI frontends for CLI applications rapidly and keep them simple at the same time.
Today of course there are things like CircuitPython, and I enjoy using it too, but it's such a beast that it's really impenetrable for someone at my skill level if I want to add low level functions.
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