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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 . How does Tcl fare under these criteria?
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 de…
Absolutely. I would have hated to see things like
set x [ expr $y + $z ]
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Last use I remember seeing for it was in scripting Intel FPGAs https://www.intel.com/content/www/us/en/docs/programmable/68...
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.
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 . How does Tcl fare under these criteria?
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 l…
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Tcl Improvement Proposal (TIP) 602[0]. [0] https://core.tcl-lang.org/tips/doc/trunk/tip/602.md
One example from the document: > Consider the naive attempt to clean out the /tmp directory. > cd /tmp > foreach f [glob *] {file delete -force $f} > A file ~ or ~user maliciously placed in /tmp will have rather unfortunate consequences.
i learned a few new habits since then. i almost never use rm -r and i avoid "*" as a glob by itself. instead i always try to qualify "*" with a path, remove files first: "rm dir/*"; and then remove the empty directory. "rmdir dir/"
if i do want to use rm -r, it is with a long path. eg in order remove stuff in the current directory i may distinctly add a path: rm -r ../currentdir/*" instead of "rm -r *"
related, i also usually run "rm -i", but most importantly, i disable any alias that makes "rm -i" the default, because in order to override the -i you need to use -f, but "rm -i -f" i NOT the same thing as "rm". rm has three levels of safety: "rm -i; rm; rm -f". if "rm -i" is the default the "rm" level gets disabled, because "rm -i -f" is the same as "rm -f"
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.
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 ri…
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.
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 de…
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).
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One example from the document: > Consider the naive attempt to clean out the /tmp directory. > cd /tmp > foreach f [glob *] {file delete -force $f} > A file ~ or ~user maliciously placed in /tmp will have rather unfortunate consequences.
i once managed to create a directory named ~ using the mirror tool written in perl. then i naively tried to remove it using "rm -r ~" and started wondering why removing an empty directory would take so long, until it dawned on me... i learned a few new habits since then. i almost never use rm -r and i avoid "*" as a glob by itself. instead i always try to qualify "*" with a path, remove files first: "rm dir/*"; and t…
It has a syntax of your expectations, functionally existing as a set of boundaries, and you can hook it to always run as a wrapper for some set of commands. It essentially stages the wrapped command and if none of the boundaries are violated it goes through. Otherwise it yells at you and you need to manually override it.
For instance, pretend I'm ok with mv being able to clobber except in some special directory, let's call it .bitcoin or whatever. (chattr can also solve this, it's just an example). The tool can be implemented relying on things like bpf or preload
Originally I wanted it as a SQL directive ... a way to safeguard a query against doing like `update table set field=value expect rows=1` where you meant to put in the where clause but instead blew away an entire column. I think this would be especially useful surfacing it in frameworks and ORMs some of which make these accidents a bit too easy.
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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.
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 :-)
But most of my work isn't playing and I don't want it to be built on hacks.
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.
Why did they remove tilde '~' as a convenient shortcut for the Home directory?