[tclmeelmo]

I really, really like that "Why?" explanation page; I feel like many projects could benefit from copying that idea.

Frequently, the first thought I have when I see projects is, "okay, neat, but why does this exist?", and the answer takes some digging. It's wonderful that in this example the answer is made so obvious.

[beachstartup]

> We (BitKeeper folks) did our GUI interfaces in Tcl/Tk years ago because it meant we could have one gui person and get the same gui tools on Windows, Mac, Unix, and Linux. Yes, somewhat clunky (less so over the years), but as a small start up it was great not having to have a developer for each platform, both for initial coding and for ongoing maintenance.

hey, that describes my very first development job! i wrote a cross-platform tcl-based installer for a desktop application at the first company (a small startup) i ever worked for. it was really easy to write (i was literally 17 years old) and there were fairly solid libraries for doing windows-y registry-ish things and unixey install things too. one of the senior guys on the team took my code and integrated it into their cross-compiled build system and it spat out a very decent product that helped our users install the program on i think 3 or 4 different platforms (win95, linux/X, and solaris, possibly HPUX or some other weird platform). that was my very first significant contribution to any software project.

i seem to remember that at the time the shrinkwrapped installer licenses cost $10's of thousands for commercial use. it probably took about 60-80 hours of my time at $17.50 an hour... clearly a bargain.

[tyingq]

> I really, really like that "Why?" explanation page;

Me too. Especially the comparison of tcl to their language:

  set x [expr {[lindex $red $i] - [lindex $blue [lindex $green $i]]}]

  vs

  x = red[i] - blue[green[i]]

I had to work in Tcl early in my career...80 hours a week for a straight year, so I recognized that madness immediately.

[nilkn]

Keep in mind that this example was (presumably intentionally) cherry-picked to show off the worst of Tcl's syntax. It's not really representative of how expressive the language can be in the right context, and it doesn't show the benefits that you can get from having a very simple, regularized syntax with little added sugar.

On the topic of expr, though, it can be avoided if desired in favor of Lisp-style prefix operators: http://www.tcl.tk/man/tcl8.5/TclCmd/mathop.htm

[luckydude]

That example was contrived but it wasn't designed to show off the worst of Tcl's syntax. There is worse out there.

Little wasn't a slam on Tcl, if you think that then you miss the point. Little is trying to bring people to Tcl. The Tcl ecosystem has a boatload of good stuff, people should check it out.

But many people are put off by Tcl's syntax, it's fine for glue, which is what Ousterhout intended, but it sucks for 300,000 lines of code. If you want to write big programs then perhaps some type checking could help you. And perhaps some familiar syntax might help. Little is for people that have to maintain a pile of code.

[nickpsecurity]

Whats the best resource for Tcl ecosystem and getting its main benefits?

[luckydude]

http://www.tcl.tk/about/language.html

is decent place to start. Then move on to

http://www.tcl.tk/software/

and there are all the Tk (GUI) APIs and libraries.

If you wade through that, or you get stuck, #tcl on freenode is a great resource.

Edit: #tcl told me to pass on this:

https://core.tcl.tk/jenglish/gutter/index.html

[ArkyBeagle]

Tcl is fine for big projects. Use OO as does Tk. Use namespaces. And type checking isn't exactly difficult in the language. Some combo of catch {} and scan usually does it for me.

[googie]

SQLiteStudio developer here. I think it's a project which could be considered big. Version 2.x.x was written entirely in Tcl and the main problem was memory sharing with threads. There's none. Threads can communicate only by messages. Worse than that - each thread has to load very same packages and same procedure definitions (into separate memory segment) for each thread that wants to use them. Threads in Tcl are like processes that can communicate through pipe. It's a major pitfall of this language in context of more complex projects. Besides that it is a very nice language to use and read. Gives quick results with little effort. I still use it almost every day, just not for complex projects.

I'm aware of tsv package (shared variable), but this is just sharing scalar variables or arrays. You cannot share objects, procedures, namespaces, resources, etc - and that is the major reason for sharing memory across threads.

[ArkyBeagle]

Tcl just totally wants to be event driven and single-threaded. I agree wholeheartedly with your assessment of threading in Tcl - the standard Tcl ideology is "don't use threads." It was a pretty deliberate decision as I recall.

[eggy]

Message passing without memory sharing. Isn't that what Erlang processes are? Is it because having to load the packages into the thread makes it too large? Just curious.

[tyingq]

There are things to like about tcl, but lists aren't really one of them.

Not cherry picked, an "official" page describing lindex: http://wiki.tcl.tk/1481 Objectively compare that with most any other language's docs for lists/arrays/whatever. "Everything is a string" does have some downfalls.

[nilkn]

I think you might have misinterpreted my point. When I said it was cherry-picked, I did not mean that it wasn't a legitimate example or that lindex is not a real, standard Tcl function. It's a completely fair example and is something that is liable to happen in practice.

All I meant is that it was clear from the context that an example was chosen showing a weakness of the language (relative to standard C-like syntax) and that it's not quite fair to judge the whole language based on that one example.

Tcl's incredibly simple syntax and lack of syntactic sugar are what lead to situations like that example. But those same things are also responsible for making the language Lisp-like and fairly homoiconic. You can do incredible things in Tcl thanks to its simple syntax which is amenable to macros and code generation.

[ArkyBeagle]

It's really important to use reduction of strength for lindex references:

set j [ lindex $red $i ]

set k [ lindex $green $i ]

set m [ lindex $blue $k ]

set x [ expr $j - $m ]

[kevin_thibedeau]

> so I recognized that madness immediately.

It's just bizarro lisp without the parentheses.

[fancy_pantser]

It combines the power of Visual Basic with the readability of PostScript.

[luckydude]

Thanks. Given the state of the world we felt that not answering why would just get a pile of "Neat|WTF|Huh - why did you do this?"

[tclmeelmo]

I should have also said in the original comment that Little, beyond the website, looks genuinely neat and I'm looking forward to exploring it further.

I just finished skimming through the paper you have linked on the site and liked it quite a bit. It directly answered another question I had, which was what would it take to implement Lisp-style syntax in the same fashion as you did for C-style syntax? I'd normally talk myself out of ideas like that, but your paper is talking me into thinking about it more.

Thanks for sharing all of this!

[luckydude]

Our pleasure. We're around on the irc channel or the forum or someplace there is a mailing list (if not, [e-mail] gets to all the people that are current hackers).

I'm tickled pink that Little is on the front page of hacker news.

[amelius]

> We (BitKeeper folks) did our GUI interfaces in Tcl/Tk years ago because it meant we could have one gui person and get the same gui tools on Windows, Mac, Unix, and Linux.

Ok, sounds reasonable. Except... now you have to hire another person to do language development/maintenance :)

[luckydude]

Now that's a valid point. So it's 2/3rds instead of 1/3rd but the guy doing the language is a languages/compiler guy (used to be professor at Brown) and he loves this stuff. So not a big money win but definitely a big karma win, he's having fun.