Tcl 9.0

https://www.tcl-lang.org/software/tcltk/9.0.html?post=new

by bch • 2 years ago

406 239 2 years ago

cmacleod412• 2 years ago

The first major release in 27 years. 64-bit internal structures, so data can be huge. Full unicode with all the funky new emojis. Zip filesystems, etc., etc.

There's lots of new stuff, and some old cruft has been dumped, so some programs may need a few updates, but there's still a high level of compatibility. The page above links to release notes with details of what's in and what's out.

Zuider• 2 years ago

Why did they remove tilde '~' as a convenient shortcut for the Home directory?

bch7• 2 years ago

Tcl Improvement Proposal (TIP) 602[0].

[0] https://core.tcl-lang.org/tips/doc/trunk/tip/602.md

cmacleod412• 2 years ago

In the long run, special cases like that often turn out to be more trouble than they are worth. If an ordinary file happened to start with '~' it would not be handled correctly. So you either accept or ignore that potential problem, or you have to write extra code to work around it. It's safer to not have such special cases at all.

Koshkin2• 2 years ago

Just recently I used '~' in the remote target path in the scp command, and, somewhat unexpectedly, it created the directory with that name and put the files there.

isr• 2 years ago

In 99% of cases, yes - this is a pain in the backside. Long ago I adopted something from the plan9 way of doing things (when I was heavily using acme).

Just symlink /h to /home. So ~user becomes /h/user, in places where ~ is not expanded for you.

wduquette11• 2 years ago

The Zip filesystem stuff is wonderful change to see: it takes a number of techniques that were common in the community (if you had the right tools and knew how to use them) for building standalone applications, and makes them part of the basic toolkit in a standard way. It's a truly excellent change, and I'm glad to see it.

packetlost• 2 years ago

Can you explain what zip filesystem is?

Klonoar• 2 years ago

The only time I’ve dealt with Tcl in recent memory was for some MacPorts portfile stuff.

Anybody using it for something else and can speak to why you’d use it today? Genuinely curious; I don’t hate the language but can never bring myself to enjoy it either.

metadat• 2 years ago

Eggdrop IRC bots. Even 25 years since I first created one, Eggdrop is still the best and most reliable + flexible IRC bot platform, and comes with native support for Tcl.

frankjr• 2 years ago

Curious as well. The only time I've seen it used in the wild is Redis' test suite. https://github.com/redis/redis/tree/unstable/tests/integrati...

aidenn02• 2 years ago

Tk based GUIs work across pretty much all desktop platforms and are much less resource intensive than electron and friends.

criddell6• 2 years ago

Is Electron really considered a competitor to Tk based GUIs?

In my (limited) experience, Tcl/Tk is great for basic stuff but I don't think you could do even a small part of what you can do with an html + css + javascript GUI.

catherinecodes• 2 years ago

Absolutely. It's even been remarkable stable--programs written 20 or 30 years ago work without any kind of modification.

jamal-kumar2• 2 years ago

Last use I remember seeing for it was in scripting Intel FPGAs

https://www.intel.com/content/www/us/en/docs/programmable/68...

duskwuff2• 2 years ago

Tcl is widely used in EDA automation in general - it's not just an Intel thing. Xilinx, Synopsys, Cadence, and Mentor all use Tcl extensively, for example.

neves• 2 years ago

When I had contact with TCL for a networking class in the 90's I already knew Python and didn't like that "everthing is a string" pathos.

For me the greatest TCL contribution was Ousterhout's dichotomy: https://en.wikipedia.org/wiki/Ousterhout%27s_dichotomy or by the author himself: https://web.stanford.edu/~ouster/cgi-bin/papers/scripting.pd...

vFunct4• 2 years ago

It's the scripting language of the EDA industry. If you're designing computer chips, you're using TCL. Cadence and Synopsys standardized on TCL 30+ years ago.

It's strength is that you get to operate EDA tools as if they were shell script commands, like run_my_task -option_a -option_B

If you aren't designing computer chips, you have no reason to use it. It's a horrible language.

The sooner the EDA industry can get rid of TCL, the better.

doublerabbit3• 2 years ago

If you aren't designing computer chips, you have no reason to use it. It's a horrible language.

What an unfair statement to make; by no means is it an horrible language. Just because it doesn't fit your tastes doesn't make it "horrible".

That's like me saying having to start a line of Python with three spaces is annoying design which makes it an horrible language. Take your statement elsewhere.

Karrot_Kream3• 2 years ago

I'm curious why you feel this way.

A long time ago as a college student I used Tcl in an EDA internship. It was awful for reasons completely unrelated to Tcl. There was a library of tool-specific primitives. The primitives were badly documented, badly tested, and nobody actually understood how any of it worked except cargo-culting and copy-pasting each others' scripts. Code only worked on the happy path and there was almost no thought given to edge cases. There was no culture of code review so nobody scrutinized your code to find out whether you were using Tcl in the right way or not. I'll grant, though very lightly, that Tcl has more accessible metaprogramming facilities than Python which makes it easier to misuse than Python. Similar to how Ruby in the hands of a undereducated/bad Ruby programmer is also quite gross.

But I had the same issues using Perl in the EDA industry. The conclusion I came to was that code standards were just abysmal in EDA because code was largely seen as a cost-center activity rather than a profit-center activity as the real output was the ETL or the device and not the code that went into it.

I re-learned Tcl when I was older and when my time in EDA was a faint memory and I found the language a joy. It was remarkably easy to get started in and really easy to build an application out of. This experience further made me reflect on how bad the code culture in EDA was.

So I'm curious what specifically you'd see the EDA industry move to and how you think it would fix the problems EDA currently has with Tcl. Python, is the successor I imagine? That said my actual time in EDA was very short so I welcome the opinion of an actual insider.

wduquette11• 2 years ago

I think of Tcl as Lisp for C programmers; by which I mean, Tcl give you the metaprogramming capabilities you get with Lisp in a language that looks more like C, plays well with C, is much more straightforward than your typical shell language, and has a cross-platform GUI. A skilled Tcl programmer can do magic.

I spent ten years, from 2005 to 2015, programming almost entirely in Tcl/Tk and I loved it. Since then I mostly use it for casual scripts rather than for writing apps; but it's still my #1 choice when I need to do some scripting to automate something at the OS level.

wduquette11• 2 years ago

I should add...Tk is the easiest GUI toolkit I've ever used (and I've used a bunch of them). It's got all the basic stuff you need, either built-in or readily available. But it comes from the classic desktop GUI world, you have to work at it to make it look nice, and it's a pain to do webpage-like layouts with it.

I wouldn't do an end-user GUI in Tk at this point; but for in-house tools that need a GUI and don't need to be on the web it's hard to beat.

bch7• 2 years ago

Standard fare:

BigIP iRules in F5 network appliances (and A10 appliances)[0], orchestration in Argonne National Labs super computer[1], Tealeaf[2], Python Tkinter[3] …

I use it day to day because it’s got a great balance of Lispyness and simple scriptyness, and a great C interface. It’s got a fine REPL, and can be built up (by writing in C) with extensions that are 100% first-class canonical Tcl, in good part (wholly?) because Tcl is such a simple language[4], and homoiconic[5]. A joy to develop in and use.

[0] https://community.f5.com/kb/technicalarticles/irules-concept...

[1] https://www.mcs.anl.gov/~wozniak/papers/Swift_Tcl_2015.pdf

[2] https://www.acoustic.com/pdf/Acoustic-Experience-Analytics-%...

[3] https://docs.python.org/3/library/tkinter.html

[4] https://www.tcl-lang.org/man/tcl/TclCmd/Tcl.htm

[5] https://stackoverflow.com/questions/6492704/what-exactly-doe...

vodou• 2 years ago

Quite common in space industry. It is the script language used in many (all?) SCOS-2000 based mission control systems. Yes, is is actually used to control satellites and spacecrafts.

robinsonb52• 2 years ago

I used it a few weeks ago to fetch and display access timing histograms in an FPGA project.

wduquette11• 2 years ago

I should also note that Richard Hipp, the creator of SQLite, says that SQLite is coded in Tcl. The database engine itself is coded in C, of course; but the vastly larger test suite is mostly coded in Tcl; and it's the test suite that makes SQLite the reliable engine that it is. The test suite persists; the engine's been re-written in whole and in part.

bch7• 2 years ago

Indeed, SQLite started life as simply a Tcl extension[0] that “escaped into the wild”. Redis was initially prototyped in Tcl too, and ‘antirez has nice things[1] to say about Tcl.

[0] https://sqlite.org/tclsqlite.html

[1] http://antirez.com/articoli/tclmisunderstood.html

smartmic• 2 years ago

I often use the tool that is closest to another tool I am using. The closeness may be due to a common heritage, both technical and cultural. A common thread between the two is often high quality, maturity, cross-fertilization, long-term commitment, etc.

Now when it comes to Tcl, I use it for the above reasons because it is so convenient for writing scripts to use SQLite. In other words, it is my go-to wrapper for many SQLite applications. This is mainly related to (rapid) prototyping use cases.

From https://sqlite.org/tclsqlite.html :

The SQLite library is designed to be very easy to use from a Tcl or Tcl/Tk script. SQLite began as a Tcl extension and the primary test suite for SQLite is written in TCL. SQLite can be used with any programming language, but its connections to TCL run deep.

oldlaptop8• 2 years ago

If there's any better relational database API, in any language, than SQLite's Tcl interface, I've not seen it yet. (And the reasons SQLite's Tcl interface is so good would either be hard to replicate without Tcl, hard to replicate without SQLite, or both.)

forinti2• 2 years ago

I used it a few times, mainly because of Freewrap. With very little code I was able to write a Windows app with GUI that I could distribute easily as an executable:

  - A backup app for an online sales application (inputs items and spits out a file);
  - An app to fix files in a buggy POS for a large retail chain (this might have been used in thousands of machines, I can't recall the details now);
  - A small app to copy Forms/Reports to the server, fire compilation, and push the new file to git;
  - A wrapper for gs to help a media department easily join many PDFs into one file.

All these have a page or maybe two of code.

progmetaldev11• 2 years ago

I don't know if you'll see this, since it was a couple days ago, and I've been reviewing multiple posts. I think what you describe is exactly what got me into programming (beyond a hobby, which was brought on by BASIC games in the 80's), but also what really hooked me into writing code for a living.

These all seem like a huge deal, unless you don't understand business and their needs. I can easily see how all four solutions could provide enormous value. For myself, these are the types of things that I got involved in programming professionally for. I think it's impressive that you were able to take a language like Tcl (not traditionally taught in university), and able to find a useful library to implement your logic.

Beyond BASIC games in the very early 80's, Visual Basic and the "hacking" tools for AOL, were a huge inspiration for myself. I dipped my toes into some weird libraries to solve some issues, that are still used today, in companies that you would never expect to be using something so simple and crude, but sturdy. Crash out with a useful message if something is wrong, do nothing on failure. Not for regular consumers, but perfect for internal staff that load data into a database, and can understand "row X is not compatible with this data type", or "This transformation rule fails because X occurred," being some rule that can't be expressed through SQL where the data is stored (but was able to be imported).

IshKebab3• 2 years ago

The only reason to use it today is because you're forced to by the EDA industry. Otherwise there are far far better options.

That also means this release is basically irrelevant for the next 10 years because that's about how long it takes the EDA vendors to update their bundled TCL versions.

cmacleod412• 2 years ago

It's unfortunate that people who dont "get" Tcl feel forced to use it because they are in EDA.

I used to have the opposite problem. My employer would not allow me to write anything mission-critical in Tcl because they thought other people would not be able to maintain it. But now that I'm retired I can write as much Tcl as I like, which is quite a lot :-)

fullstop4• 2 years ago

I use it for "expect" because it just works.

dvzk• 2 years ago

Same. I learned Tcl recently for /usr/bin/expect. I wasn't happy to be forced into using yet another esoteric language, but Tcl itself is strangely fun: it's like a more expressive and functional Lua.

stackghost• 2 years ago

Anybody using it for something else and can speak to why you’d use it today? Genuinely curious; I don’t hate the language but can never bring myself to enjoy it either.

For a long time it was the only way to get a decent IRC bot going, because eggdrop[0] was a Tcl wrapper around a small C core, but the only place I've seen it in the wild other than IRC bots was in the Xilinx toolchain and once when I was in undergrad some TA was using it to get telemetry from Tektronix oscilloscopes in the robotics lab.

[0] https://www.eggheads.org/

throw0101b3• 2 years ago

Anybody using it for something else and can speak to why you’d use it today?

It was often used as an embedded language (e.g., in F5 load balancers), especially in the pre-Lua days.

BoingBoomTschak5• 2 years ago

Copy-pasting a "hype" checklist I made some eons ago:

* Extremely consistent and elegant syntax - whole syntax/grammar is described in 12 rules in a single man page (Tcl(n)) of 150 lines and there's no reserved keyword. Nearer to CL than Python on that point.

* Homoiconic through strings (like almost every language with eval) but most importantly, through "list-like" strings.

* Official man pages! No web-only and spec-like doc like cppreference nor lackluster "minimalist" stuff like pydoc (compare `pydoc print` with `man n puts`, for example).

* One of the simplest if not the simplest interaction with C, letting you write C plugins very easily (with critcl and swig to help).

* Not slow, not fast. In the same ballpark as cpython or Perl; doesn't need a tracing garbage collector, refcounting does the job since no cycles are possible by design (worse for throughput, but lighter runtime).

* Fun type system that is superficially "everything is a string" (like sh) but in reality "everything is a tagged union with on-the-fly conversion when needed and a guaranteed string representation". Allows for transparent serialization (`puts $mydict stdout` <=> `set mydict [read stdin]`), like CL's read/write.

* Powerful introspection through `info` (mainly). Allows for stuff like getting the name/body/arglist of a procedure, get all the registered procedures, know if a variable exists, get information on the stack frames and their content, etc... Together with `trace`, you can even write an internal debugger in few lines.

* Procedure arguments are passed by pointer with a copy-on-write system: don't modify the argument and you don't get any memory copy. To you, it just looks like regular passing by value.

* Modifying the procedure arguments is done via `upvar`: in Tcl, a variable reference is just a name (string) attached to a relative stack frame number, quite elegant considering the language's core concepts.

* If you use at least the builtin extensions (thread, http, tdbc, tcltest, msgcat) and the very basic tcllib/tclX/tclUdp/tklib packages, you're almost set for life. Personally, I also recomment the very convenient tclreadline, tdom, pipethread, tablelist and tclcurl.

* Channels is one of the cleanest I/O implementation I've ever used with some cool features:

- Transformations allowing filters like deflate/zlib/gzip or TLS to be put on a channel (see `transchan` for the API).

- Reflected aka virtual channels, to make your own channels. Basically like glibc/BSD's unportable fopencookie/funopen or CL's gray streams.

- Centralize a lot of ioctl/fcntl mess and even more (like defining the EOF char) in `chan blocked/configure/pending`.

- Integration with the event loop via `chan event/postevent` allows for a nice callback oriented approach to sockets and pipes.

- Other third-party channel types include pty (expect), random, memory or fifo (memchan).

* Builtin event loop (see `after`, `vwait`, `socket -server` and `chan event`) for powerful and seamless concurrency/command scheduling. Much simpler than Python's very "AbstractBeanFactory" asyncio.

* An elegant thread extension consisting of an interpreter per thread and no raw access to other thread's memory. Comes with both simple (`thread::send/broadcast/transfer`) and performant (`tsv`) synchronization/communication facilities.

* Finally a sane, light and portable (even more with Tile) GUI toolkit: Tk.

* One of the fastest Unicode aware regex implementations, written by Henry Spencer himself. Has its own greater-than-POSIX-ERE syntax called ARE, not as complete as PCRE (lacking lookbehind constraints, most importantly), but still great for an hybrid NFA/DFA engine. Performance comparison with Perl: https://github.com/mariomka/regex-benchmark/pull/44.

* `uplevel` (eval a script in a different stack frame) and `tailcall` (replace the current procedure with another command) let you augment the language by implementing control structures and keywords yourself. Inferior to CL's synergy between unhygienic macros, "naked AST" style homoiconicity, symbols as first-class objects, gensym and quasi-quoting, but still quite powerful.

* Safe interpreters let you do very fun things like config files in Tcl with limited access to the machine and master interpreter.

* Recent versions (>= 8.5) really embraced FP with:

- Real lambdas (but not closures, these have to be emulated) through apply.

- Purer hash maps (dict) than ugly sticking-out-like-a-sore-thumb arrays.

- Lisp style prefix arithmetic (allowing for `* 3 [+ 1 2]` instead of `expr {3 * (1 + 2)}`) including sane behaviour for more than two (reduce) or zero (neutral element) arguments.

- Builtin map/filter (lmap) with 8.6. See https://wiki.tcl-lang.org/page/Functional+Programming for more.

* Multiple more-or-less powerful OO systems (now based on the builtin TclOO): [incr Tcl] for C++ style OO, XoTcl for a take on CLOS or Snit for something Tk oriented.

* Some massive issues on the top of my head: lacking a LSP/SLIME equivalent, the warts of the weird type system (no way to differentiate between atoms and single element lists or evenly sized lists and dicts), missing metaprogramming facilities like quasi-quoting, no official support for UDP and UNIX domain sockets, no GC for class instances (cf https://core.tcl-lang.org/tips/doc/trunk/tip/550.md), no FFI in core, subtly broken exec (cf https://core.tcl-lang.org/tips/doc/trunk/tip/424.md and https://core.tcl-lang.org/tips/doc/trunk/tip/259.md)

Here are some project I made with it, still worth using compared to CL which is my true love, simply because its stdlib is better suited for a lot of tasks:

  https://git.sr.ht/~q3cpma/mangadex-tools
  https://git.sr.ht/~q3cpma/rymscrap
  https://git.sr.ht/~q3cpma/lemonbar-tcl
  https://git.sr.ht/~q3cpma/tcl-misc

cmacleod412• 2 years ago

Hey, you missed out coroutines :-)

zvr3• 2 years ago

This is a great list.

* Safe interpreters let you do very fun things like config files in Tcl with limited access to the machine and master interpreter.

I keep looking for similar functionality in Python (the scripting language of choice for many, nowadays) but I am always disappointed.

sph2• 2 years ago

Sold. I know what I'm doing this weekend.

alhimik45• 2 years ago

refcounting does the job since no cycles are possible by design

So double-linked list is impossible to define?

BoingBoomTschak5• 2 years ago

For the few interested people, took the time to make a final version in Markdown with lots of links and some improvements/proofreading: https://gist.github.com/q3cpma/a0ceb6a7c6a7317c49704630d69b7...

natrys• 2 years ago

I use it to write long running little scripts. It's better than shell, and imo more useful out of the box than Lua. They are basically for I/O (often using sqlite which it has great integration with, or using expect which is also great) so I don't care about performance, but I like that it requires much less memory compared to say Python for that kind of little things (there is also jimtcl which is also neat in this regard).

badsectoracula• 2 years ago

Some time ago i was playing with a Raspberry Pi and wanted to write some code in there. The Gtk3-powered Geany was WAY too slow (like, type and wait for the letter to appear slow). I recompiled it to use Gtk2, it was much faster but also it was buggy (the code display was getting messed up).

Nedit (based on Motif) on the other hand was both very fast (faster than the Gtk2 Geany) and bug-free - it worked perfectly. But i wanted Geany because of the file browser sidebar.

So i wrote a small Tcl/Tk script to display a list of files using a filter in a directory and call Nedit to edit them when you doubleclicked. Also added a few buttons to call make, make clean, open a terminal, make a new file, etc and worked perfectly.

A few years since then i made a few improvements and modifications to this script and use it on my main PC whenever i want to work on C source code - though i use Krita instead of Nedit here (Krita has its own file browser sidebar but i find the way it works annoying - and doesn't have all the extra stuff i've added over time to the script).

The neat bit is that it reads a Tcl file from the home directory for "global" configuration (e.g. which editor to use, how to run terminal commands, etc) and then a Tcl file from the current directory for project-specific stuff, all of which having access to the main script's own procs for things like calling terminal commands, showing a few dialogs, etc.

I've uploaded the latest version of the script to my website a few days ago[0]. I've been mainly using it with Linux but a couple of years ago i also used it a bit with Windows using MSYS2 (with Notepad++ for the editor) and worked fine.

There is a screenshot on the site.

[0] http://runtimeterror.com/tools/projfiles/

pjmlp5• 2 years ago

Back in the late 90's we used it on our startup, several of companies at the time were trying the luck on Tcl based application servers, AOLServer being the most well known.

There was Vignette, and we at Intervento had our Safelayer product, loosely based on AOLServer.

Apache and IIS plugins for hosting Tcl interpreter, running on Aix, HP-UX, Solaris, Red-Hat Linux, Windows 2000/NT, with support for Oracle, Informix, DB2, Sybase SQL Server, Microsoft SQL Server, Access (only for test purposes).

Development environment was based on Emacs, eventually there was one written in Visual Basic specifically for the product, with project templates and other kinds of goodies.

However we eventually hit the limits of using Tcl, and having to rewrite parts of the platform in C.

As it was, being a gold MSFT partner gave us access to .NET before it was announced to the world, and a plan to rewrite our product into C# took place.

With the learnings of these experiences, and customisations done at client sites, the founders eventually moved on and created one of the best products for no code development still going strong nowadays, OutSystems.

Never used Tcl again since those days.

fraber• 2 years ago

AOLServer (now Naviserver again) is still the base for the largest open-source project management system: ]project-open[ (https://www.project-open.com/)

jasomill• 2 years ago

It has expect[1], a nice tool to automate terminal applications.

Two examples:

- Adding convenience features to the Cisco IOS CLI (e.g., ^D to exit).

- Implementing the back end of a native WPF Windows GUI application that downloads spooled print jobs from a third-party system that only provides remote spooler access through a full-screen interactive terminal application running over ssh. This application also makes use of another nice Tcl feature, its trivially-implemented remote protocol[2].

[1] https://core.tcl-lang.org/expect/index

[2] http://corex.tcl-lang.org/tcllib/doc/tcllib-1-18/embedded/ww...

breck2• 2 years ago

For those that are new to Tcl, there's an alternate universe where Tcl is the browser language instead of Javascript:

"Interesting footnote: the founding of Netscape occurred at the same time I was deciding where to go in industry when I left Berkeley in 1994. Jim Clarke and Marc Andreessen approached me about the possibility of my joining Netscape as a founder, but I eventually decided against it (they hadn't yet decided to do Web stuff when I talked with them). This is one of the biggest "what if" moments of my career. If I had gone to Netscape, I think there's a good chance that Tcl would have become the browser language instead of JavaScript and the world would be a different place! However, in retrospect I'm not sure that Tcl would actually be a better language for the Web than JavaScript, so maybe the right thing happened."

Source: https://pldb.io/blog/JohnOusterhout.html

hathawsh• 2 years ago

Perhaps. I think one of the main reasons JS caught on is that it had no significant baggage and the designers could take it in any direction it needed to go. Every language used by more than a few people, no matter how good it is, has some baggage. As a result, in that alternate universe, the browser scripting language landscape might have been a lot more fragmented.

breck2• 2 years ago

it had no significant baggage and the designers could take it in any direction it needed to go

This is a fantastic insight and put very well. Thank you.

New platforms unlock rare opportunities for new languages that have no baggage and can focus on fully exploiting the new platform.

IshKebab3• 2 years ago

I doubt the world would have stuck with TCL if that had happened. JavaScript was good enough for people to put up with. TCL definitely isn't. More likely we would have ended up with TCL + something else, with TCL deprecated.

kevin_thibedeau• 2 years ago

The work on the safe subset of Tcl for the web can be exploited today to run untrusted scripts in an easily managed sandbox. If you want you can strip away enough commands for the language to be non-Turing complete.

Koshkin2• 2 years ago

maybe the right thing happened

Absolutely. I would have hated to see things like

  set x [ expr $y + $z ]

all over the place. (As a command language, this is not so bad.)

froh• 2 years ago

funny enough, tcl browser plugins were around from at least 1996

https://sunsite.icm.edu.pl/pub/programming/tcl/plugin/

I'm pretty sure some fellow students came into our computer room before that, "look now there even is a TK plugin for Mosaic!". it was not in "look it's like gopher but with a mouse!" days, but not that much later.

however you of course had to _do_ something to use it, while JavaScript came out of the box (once it was there).

gorgoiler3• 2 years ago

I know of Tcl but I don’t know anything about its structure. The number one thing I ask of a language is consistency: the minimal amount of magic and most of the language implemented in itself. Ruby almost got there and then, for me, slipped up on class << self.

How does Tcl fare under these criteria?

wduquette11• 2 years ago

The Tcl language is made up of commands; a command has a name and takes an argument list, with which it can do literally anything. The standard commands are written in C; Tcl `procs` are commands that are written in Tcl. The control structures, like `if` and `foreach` and `while` is just a Tcl command. The `proc` command that defines a proc is just a Tcl command.

I think of it as Lisp for C programmers.

So: is the language implemented mostly in itself? No, it's mostly implemented in C. Is there a minimal amount of magic? No; the amount of magic you can do is effectively unlimited.

bch7• 2 years ago

Is there a minimal amount of magic? No; the amount of magic you can do is effectively unlimited.

I might be mistaken, but I think the OP was asking if there is surprising magic (I.e. special cases/considerations) built into the language, in which case I’d say, “No, Tcl is not “magical”, but surprisingly simple and regular.” That said, indeed it’s powerful in its application of its primitives, but you do still need to mind some things (don’t pretend* you can quote better than the quoting engine, don’t pretend* you can do lists better than the list processor, …). Not magical though - very understandable.

*rules are meant to be broken, blah, blah, but the “gotchas” are new practitioners falling into this, or advanced cases, falling into this…

robinsonb52• 2 years ago

It's also absurdly easy to integrate into C or C++ projects, or to write an extension in C or C++ which can be loaded to implement new commands.

gorgoiler3• 2 years ago

Thanks for this explanation. It was very helpful. In terms of magic I meant it simply as how big is the set of unchangeable axioms, as opposed to how many things are derived in the language itself from a more minimal set of magical axioms. With Lisp being the language with the least magic lisp for C programmers was insightful!

sph2• 2 years ago

The Tcl language is made up of commands

As someone that is stubbornly trying to design a Smalltalk-Forth hybrid syntax, where everything is words, nay, messages in a declarative/concatenative pipeline, without success, reading this makes me inappropriately giddy.

I need to learn Tcl.

orthoxerox2• 2 years ago

Tcl is incredibly consistent, because it's homoiconic.

talideon• 2 years ago

Tcl's magic is mainly from uplevel and upvar as they allow you to do crazy stuff with the callstack to enable all kinds of metaprogramming. It's not a lot of magic, but it's very powerful.

smrtinsert• 2 years ago

It's a lot of magic. New control structures mean dsls are as easy as thinking about them

tpoacher• 2 years ago

I recently asked HN if Tcl is still relevant in 2024 https://news.ycombinator.com/item?id=41108667

Nice to see a new release coming out not too long after such a question :)

fithisux2• 2 years ago

It is very still relevant.

It is also supported on Scilab.

Karrot_Kream3• 2 years ago

New Notifiers: The central event handling engine in Tcl is now constructed on top of the system calls epoll or kqueue when they are available. The select based implementation also remains for platforms where they are not.

This is huge! A big portion of why concurrency in Tcl was so dated and why the language was considered so non-performant was because it relied on `select` despite `epoll` and `kqueue` being available for at least a decade.

Tcl is one of my favorite languages because of how easy it is to get started with and how easy metaprogramming is.

kragen3• 2 years ago

mostly people consider tcl non-performant because fundamental operations are about twice as slow as cpython, which is no speed demon: https://news.ycombinator.com/item?id=41637953

another reason is that we don't know how to write fast tcl, as i inadvertently demonstrated in that thread

sedatk2• 2 years ago

I can't overstate my love for Tcl, yet I had only a little chance to use it when writing XiRCON IRC scripts back in the late 90's. Such an elegant language: simple, easy to learn, flexible. I call it Lisp for humans. I wish it were more popular. So glad to see that it's still alive and kicking.

mattw2121• 2 years ago

Agreed, my only exposure to Tcl was writing IRC scripts for bots and I have nothing but fond memories of the experience.

sshine• 2 years ago

Same. Such a simple life writing text-only event handlers.

anthk• 2 years ago

I call it Lisp for humans.

Except for upvar.

makmanalp• 2 years ago

What's upvar? :-)

mdaniel6• 2 years ago

CMake similarly is sick in the head: https://cmake.org/cmake/help/v3.30/command/set.html#normal (heh, I enjoy that the documentation anchor is "normal" for SET(FOO BAR PARENT_SCOPE)

sandos• 2 years ago

I also wrote TCL scripts for a IRC client in the 90s, and it was awesome. For that purpose the language was awesome. On the other hand, my other language at that time was x86 assembly so I didnt require much to be awed I guess!

doublerabbit3• 2 years ago

I'm going to give a shout out to NaviServer [0], prior called AOLServer [1]. This web server has been battle-tested and is bullet proof. When something has been used power AOL back in the day, what can you say.

OpenACS [2] is the main project of, which has existed since 1997 and that alone is highly powerful in what it can do with. Especially when coupled with TCL. It's still maintained and now supports TCL9 too!

Javascript, TCL and NaviServer (and which has it's own modules such as DNS Server, LDAP, Mail really makes an powerful tool.

If you're looking to get in to TCL and Web Development, you can really create fun with the two combined. I highly recommend that if you wish to dabble with something on the side for easy learning and plentiful features. Go take a look.

[0] https://wiki.tcl-lang.org/page/NaviServer

https://github.com/naviserver-project/naviserver

[1] https://news.ycombinator.com/item?id=35648805

https://www.linuxjournal.com/article/6164

[2] https://openacs.org/about/history

https://openacs.org/

sbuttgereit• 2 years ago

Brings back great memories and (more or less) where I learned both Tcl & SQL... Back in the mid-90's this is the stack and software I was playing with, though admittedly I was using the ArsDigita Community System proper rather than OpenACS (and back when ArsDigita was a thing).

Funny thing is I remember taking some free classes sponsored and taught by ArsDigita in an office they had in Pasadena, CA (or was it Glendale....???) they weren't too deep or long, but nice introductory stuff.

urbandw311er2• 2 years ago

Wow Tcl is still a thing? Takes me back to university days — and even 20 years ago it was considered a bit of a poor man’s UX. I’m off to read the article and see if it’s any better these days…

bachmeier3• 2 years ago

Really enjoy the language, even if I don't use it much these days. Does it still produce GUIs from 1995 on Linux? I'd still be using it today if it had halfway reasonable support for building GUIs on Linux, like they've had for ages on other platforms.

oldlaptop8• 2 years ago

A theming engine went in something like 15 years ago now; the default theme looks rather dated, but there are plenty of others. See https://wiki.tcl-lang.org/page/List+of+ttk+Themes (though the screenshots of core themes are from 8.5/8.6 - default in particular has changed a bit in Tk 9).

The "catch" is that the theming engine has its own new widgets, and so to be themed an application has to use the new API. Code from 1995 (or 2005) still produces GUIs from 1995.

bmacho• 2 years ago

Those are TK? They look good!

bachmeier3• 2 years ago

Yeah, they added that a long time ago, but it's not at all the same as built-in support. My experience was trying out fragile third-party projects with little or no documentation. The whole point of using Tcl/Tk for writing a GUI was the convenience.

Things may have changed over time. I no longer pay attention. Maybe I'll give it another try.

progmetaldev11• 2 years ago

Reminds me of using Tkinter with Python, while learning Python. There are other GUIs available, but finding examples of working code with a newer GUI is going to be more troublesome (but not impossible). I think it's just that the documentation has been centered around Tk(inter) for so long, most people just choose it as a default. I know Python has gotten better about GUI support (probably from the popularity in machine learning/AI usage), but with Tcl being less popular, you need to do some due diligence to find up to date documentation on modern GUI usage.

urbandw311er2• 2 years ago

It’s not exactly encouraging when a website for a UI tool contains absolutely no visual examples of UI on any of its main pages.

cmacleod412• 2 years ago

There is a redesign of the website in progress. In the meantime, take a look at https://wiki.tcl-lang.org/page/Showcase .

monetus• 2 years ago

That tcl wiki is actually a fossil instance iirc - the VCS the Richard hipp evangelizes.

synergy20• 2 years ago

Tcl remains to be the king scripting language in chip design ecosystem

padf• 2 years ago

Also useful if you want to do microprocessor debugging.

OpenOCD is scriptable/configurable using a small variant of TCL called JimTcl.

https://openocd.org

https://jim.tcl.tk/index.html/doc/www/www/index.html

niobe2• 2 years ago

Great to see all the love for TCL here :) Too bad it's not more popular really but even I struggle to find cases where I'd prefer it. Usually it come down to bash for simple stuff and python everything else.

stroupwaffle• 2 years ago

I’ve recently discovered Tcl and absolutely love it! It’s such a fun language.

The starpacks/starkits for packaging apps together are really nice.

For anyone interested there’s a fork of the Tcl Dev Kit at: https://github.com/bandoti/tdk

This allows one to package applications with shared libraries and all bundled together.

sedatk2• 2 years ago

Not those scenarios, but I think it still has potential to take place of embedded scripting languages like Lua, if it can keep up of course.

buescher2• 2 years ago

Language snobs and 1990s OO snobs really love to hate on tcl - yeah everything is a string or a command, and the OO extensions were kind of kludgy - but there's a design ethos to the ecosystem that is really special. Ditch tkinter, which is basically writing python to write tcl, and try doing a GUI in straight tcl/tk. Try the sqlite interface. Write a modest C extension or wrap a library. So much of it just works.

mdaniel6• 2 years ago

yeah everything is a string or a command

And you're not kidding about everything being a command - this here is some "what the fuck is wrong with you people": https://wiki.tcl-lang.org/page/comment

Including the truly stunning collection of:

- one must terminate the command with ; before one can comment

- one cannot have mismatched braces so don't try to comment out bogus code

- one cannot have a backslash in a comment but hey it's a feature not a bug because this is how they launch wish:

  #!/bin/sh
  # the next line restarts using wish \
  exec wish8.0 "$0" "$@"

since the backslash is ignored by the shell but parsed by wish

pjmlp5• 2 years ago

It made our startup possible, and the experience and learnings we got out of it, were in the genesis of OutSystems.

One of those learnings, was that I never wanted to again use a dynamic language without any kind of JIT compiler for full blown web servers.

The language is great, rewriting Tcl libraries into C on regular basis due to performance issues not so much.

rahen• 2 years ago

What do you use now? Node.js? Groovy?

eadmund2• 2 years ago

I never wanted to again use a dynamic language without any kind of JIT compiler

What about a dynamic language with an AOT compiler? E.g. SBCL implements Common Lisp by compiling everything ahead of time.

crabmusket• 2 years ago

I found an article by antirez about TCL [1] which had an interesting perspective. IIRC Redis uses TCL for its test scripts. It was linked from the documentation of https://folk.computer, which uses TCL as its scripting language. And... For that purpose I'm not sure I even hate it.

[1] http://antirez.com/articoli/tclmisunderstood.html

__s• 2 years ago

I got to work with a lot of tcl while working on TPC benchmarks for Citus

https://github.com/TPC-Council/HammerDB/blob/master/src/post...

tcl makes as an alright shell script language

criddell6• 2 years ago

Why are they still on SourceForge? To me, SourceForge feels like one of those scammy download sites that installs spyware.

an1sotropy• 2 years ago

Sourceforge still works, and is (now) reliable. The awful DevShare malware stuff that Sourceforge started (under new ownership) in 2012 was stopped (under different new ownership) in 2016.

criddell6• 2 years ago

The site is ugly and difficult to navigate. Go there and enter TCL in the search box and see how many clicks you have to do to actually find the project. Then when you click the download button a timer has to run out before the download will start.

Maybe it technically works, but it's a terrible UX.

sigzero3• 2 years ago

They mirror to Github.

https://github.com/tcltk/tcl

CarpaDorada• 2 years ago

It would be nice if the releases were cryptographically signed. I've never used Tcl/Tk before but I just downloaded the 9.0 release and I'll give it a go.

replwoacause6• 2 years ago

Are there any good tcl web frameworks ?

mdaniel6• 2 years ago

~~A very famous(? infamous?) one: https://github.com/aolserver/aolserver#readme~~

sorry, https://news.ycombinator.com/item?id=41663259 does a much better job answering than my link

replwoacause6• 2 years ago

Awesome! Can’t wait to play with this some more tomorrow. TCL looks like a fun language for my hobby projects.

v9v• 2 years ago

Rivet (https://tcl.apache.org/rivet/) may also be of interest.

replwoacause6• 2 years ago

Indeed thank you

conoro• 2 years ago

Love reading this. I spent a few years in the late 90s using Tcl/Tk to build cross-platform installers for Embedded tools/libraries, along with Expect for a bunch of our testing. One of those pragmatic toolsets for getting sh*t done.

kras143• 2 years ago

In the realm of Electronic Design Automation (EDA), TCL is ubiquitous. Virtually every EDA tool offers a TCL interface or API, making it the predominant language for tool configuration. I've always wondered why TCL hasn't gained traction in other domains. It possesses the elegance of Lisp while maintaining practicality.

pipeline_peak• 2 years ago

Anyone know if any new projects are using Tcl? Surprised they went with this

cmacleod412• 2 years ago

Some people like Tcl and use it, some people don't. The Tcl Wiki sees a regular stream of updates - https://wiki.tcl-lang.org/recent . Personally I'm working on a Usenet/Web gateway which does web serving, NNTP, caching in Redis, user db in sqlite, all implemented in Tcl - https://cmacleod.me.uk/ng .

mdaniel6• 2 years ago

Courtesy of kicking the tires on your app, I discovered: https://github.com/apnadkarni/tcl9-migrate#migration-tool-fo... (via https://cmacleod.me.uk/ng/comp.lang.tcl/67166 )

and "EuroTcl 2024 - presentation videos and slides now online" https://openacs.org/conf2024/info/schedule (via https://cmacleod.me.uk/ng/comp.lang.tcl/67134 )

dontdieych• 2 years ago

Nice. `gitk` could be better.

teleforce• 2 years ago

Fun facts, the author of Tcl and tk is Prof. John Ousterhout, and his Software Design book is in its 2nd edition:

A Philosophy of Software Design:

https://web.stanford.edu/~ouster/cgi-bin/book.php

WillAdams2• 2 years ago

This is an _amazing_ book, and one which I am currently working through --- I was reading one chapter, thinking as deeply as I could on it, then re-writing my current project using the lessons from it.

Currently on Chapter 11 (Design it Twice), so will probably just finish, then work on a top--bottom re-write (switching from a current model which has a minimal Python core for variables only, and the balance is in OpenSCAD to a new implementation where everything possible is in Python, allowing usage from there via OpenPythonSCAD: https://pythonscad.org/ )

tessierashpool9• 2 years ago

is tcl relevant beyond maintenance of existing legacy projects?

sigzero3• 2 years ago

Outstanding! I know a lot of work has gone into this release. Kudos to the TCT.

butz• 2 years ago

Tcl/tk Wayland support when?

replwoacause6• 2 years ago

I’m looking forward to installing this and having a play. Looks great

replwoacause6• 2 years ago

So I started playing with TCL for the first time this weekend after seeing this post, and here are my thoughts. I think the language is fun and much different than I’m used to, but my biggest challenge so far is just getting packages installed. There seems to be no current, modern, maintained package manager or central repository, and to do basic stuff like stand up a web server requires compiling from C source. Kinda brutal. TclHttpd failed to compile with TCL 8.6 installed because I guess there was some change in APIs. I didn’t bother spending time figuring out how to patch the C code to make it work because that’s getting in for more than I bargained for.

It’s too bad there’s not a simple way to get up and running with packages because for me so far that had been the biggest barrier to entry / deterrent. Also, I wanted to create a ES256 JWT but there’s no good way to do that apparently, due to the dated ecosystem, whereas in other languages this sort of this is just a package install away. I found a third-party solution in the form of Chilkat software but it costs $300 to license.

So overall while I think TCL is fun, I can see why people don’t choose it when they want to be productive fast and not have to fuss around with deeply manual things that are commonplace and quick in other languages.

cmacleod412• 2 years ago

Take a look at http://www.ch-werner.de/LUCK.html . This site builds custom single-file Tcl executables for various architectures. It has a large selection of packages and you can choose which ones get included in the build. E.g if you select tclhttpd to be included in the build and name the output file tcluck, you can then start the web server by running: ./tcluck tcluck/tclhttpd3.5/bin/httpd.tcl

This is still using Tcl8.6 though, it will take time for all these packages to be updated to work with Tcl9.0. I am actually running tclhttpd with Tcl9.0 myself, after making a handful of tweaks for compatibility.

cmacleod412• 2 years ago

I'm not familiar with JWT at all, but I found a description of how to generate an ES256 JWT from the command line: https://techdocs.akamai.com/iot-token-access-control/docs/ge... .

I don't know if this would meet your needs, but from Tcl you could use `exec` to run these commands and read the result.

replwoacause6• 2 years ago

Thanks for sharing this. My preference is to do it all in Tcl without having to shell out, which is possible (and easy!) to do in most other languages.

fithisux2• 2 years ago

More important than Python 3.13.

Bravo !!!!

Can't wait Scilab and Python to ship with Tcl/Tk 9.0

I think Next Scripting latest releases are 9.0 ready.

Keep an eye on Undroidwish and the Binary Releases section of the official page.

Tcl 9.0

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