Why Janet? (2023)

6/2/2026 at 9:59:15 AM

This post is refreshing - smells of the pre AI discussions on the internet. A new language, a new syntax, heavy debate with people who have spent years writing code. I think someone should start a community online where AI isnt allowed.

by krinne

6/2/2026 at 10:24:28 AM

> I think someone should start a community online where AI isnt allowed.

In case you haven't followed the saga, the latest[1] digg.com relaunch failed because they couldn't deal with the bot onslaught [2]. Whoever finds a reliable way to keep AI out of an online community first is likely to become a very rich person.

[1] Second-to-last, actually, seeing as there seems to be a new homepage right now.

[2] https://www.techspot.com/news/111698-digg-relaunch-fails-two...

by probably_wrong

6/2/2026 at 2:51:23 PM

I suspect real ways to keep AI out of a community, or really to have an online community at all, are going to be structurally incompatible with making anyone rich. The possibility of getting rich poisons the incentives.

by andrewflnr

6/2/2026 at 12:15:44 PM

We've already got models that can handle it - eg web of trust. We don't want to use them.

Plus "AI" is a spectrum, with "the AI fixed a typo for me" at one end, and "the AI writes my posts for me" at the other.

by flir

6/2/2026 at 1:37:55 PM

Web of trust has been a miserable failure because of the GPG's horrible UX and high entry barrier. It's dead, Jim.

by makkes

6/2/2026 at 2:03:52 PM

I think they were referring to invitation trees like lobste.rs.

by andrewflnr

6/2/2026 at 5:45:26 PM

That's for children. Make the Pope a certification authority, and he can certify people he trusts, and so on, until the chain reaches you. When you commit a sin, your certificate gets revoked, along with its children.

It would give the web of trust a flair of biblical damnnation, and after your fall you could always seek a new certification authority more aligned with your values, like Milei or Putin.

When a world leader dies, the tree pruning would be almost apocaliptic.

by ASalazarMX

6/2/2026 at 1:16:10 PM

> Whoever finds a reliable way to keep AI out of an online community first is likely to become a very rich person.

I believe it’s the opposite: You have to pay competent human moderators. Like here on HN.

by layer8

6/2/2026 at 1:56:48 PM

Half the posts here are AI grifting.

by LtWorf

6/2/2026 at 2:20:47 PM

That’s a pretty extraordinary claim. Do you have anything quantitative to back it up? HN has bots, I think that is a fair assumption, but half? How do you know that for sure?

by whyenot

6/2/2026 at 2:53:44 PM

[flagged]

by GroksBarnacles

6/2/2026 at 3:17:15 PM

TIL that statements of obvious exaggeration are called causal, hyperbolic statements. Who knew?

All kidding aside, I've never heard them called causal hyperbolic before. It's a good term.

by dcuthbertson

6/2/2026 at 11:21:39 AM

> In case you haven't followed the saga, the latest[1] digg.com relaunch failed because they couldn't deal with the bot onslaught [2]

Given that they wrote their goodbye post using LLMs and gave up after such a short amount of time, I don't take that at face value the same way I don't believe AI layoffs

by dwedge

6/2/2026 at 11:39:43 AM

Perhaps requiring webauthn credential for any post/comment with a whitelist of permitted webauthn hardware devices which must have touch/interaction enabled.

I'd have to read the FIDO specs, however the only place I've seen webauthn hardware pinning in the wild is with Azure AD/Entra which is ostensibly based on token GUID. If this is the only enforcement mechanism available, it's spoofable.

by ponkpanda

6/2/2026 at 12:50:04 PM

Then you’ll end up with a forum of only bots because they’ll spoof it and real people won’t put up with the hassle.

by nkrisc

6/2/2026 at 2:12:50 PM

Doesn't actually work that well. Browsers hate this, the hardware isn't actually difficult for bots to access, and privacy story is bad. There are solutions being worked on.

by wbl

6/2/2026 at 12:14:32 PM

FIDO tokens are designed to able (if authorized by the software, your web browser typically offers a pop-up where you can decline this) to prove their membership of a batch of tokens, but not their individual identity.

The Entra feature you thinking of lets somebody say "Only things which can prove they're in this list work". This could make sense if you, as their employer, issue every employee a custom DoodadCorp Doodad FIDO key and so you don't want somebody's Yubikey or off-brand generic device to work. It's stupid and you shouldn't do it in other scenarios, but your "this is how we detect humans" idea is arguably a scenario where that could make sense.

[Edited to add: This feature is called "Attestation"]

by tialaramex

6/2/2026 at 1:20:22 PM

This would result in hardware farms of such devices being automatically operated, like the existing iPhone farms used for similar purposes.

by layer8

6/2/2026 at 4:05:37 PM

Altman’s orb is as terrifying as it is because businesses might see it as a solution to a real problem—a problem he helped to create.

by Cassell

6/2/2026 at 5:02:55 PM

The reason we didn't see it in the US first is because he was probably gathering data from a pilot system. When he finishes his moonbase and/or volcano lab then we should probably start moving to the Northern Territories or the Yukon.

by throwway120385

6/2/2026 at 12:14:45 PM

Pay per interaction model? 1 cent per post.

by 21asdffdsa12

6/2/2026 at 5:49:06 PM

I think pay per account (like the Metafilter model) would be better. If you charge $10 for lifetime access and ban slop-posters, it quickly becomes expensive to be a slop merchant

by phainopepla2

6/2/2026 at 2:18:41 PM

Probably the only solution. But the penny has been deprecated so it will have to be a nickel.

by intrasight

6/2/2026 at 2:40:40 PM

Only copper was deprecated. Real $0.01 absolutely exists in your bank etc.

Anyway, marketers see a popular site like a physical billboard, where they would pay thousands a month for their message to be seen by thousands of people. If you made it cost pennies to post, and a few more pennies to boost and astroturf, AND that the post would be seen by millions of people, they'd say "By Grabthar's hammer, what a bargain!!" and order a hundred more per day...

by imglorp

6/2/2026 at 1:13:16 PM

Age verification with facial ID? ;)

by kitd

6/2/2026 at 12:01:39 PM

Isn’t the solution high-quality identity verification? There are piles of digital identity companies out there. They make money selling to banks for KYC compliance. Heck, there are background check as a service companies designed to add trust to gig economy platforms.

I used to think that a small payment could accomplish the same thing, but X selling blue check marks proved that doesn’t help much. Well, at least it’s a much weaker signal than the previous curated version.

The challenge is any barrier to entry high enough to discourage motivated spammers is also high enough to discourage casual users. That disrupts the network effects you’ve traditionally needed to bootstrap a social website.

If I was trying to get a new social site off the ground right now, I would try:

1) secure a good brand from the pre-AI era. Twitter, Digg, Friendster, MySpace. Something that motivates a first look.

2) Require third party identity verification on sign up, configured so the social site is never the custodian of PII, though require enough demographics to support high-value advertising later. Verification is free to the user, ideally provide multiple verification options- one US and one EU at minimum.

3) Target a few core communities and invest. Find the people who moderate historically great subreddits, were active in twitter communities during the good years, etc. get them in your platform. Maybe even pay them.

That should be enough to tell you if it’s going to work or not.

by pbronez

6/2/2026 at 10:38:34 AM

lobste.rs uses a web-of-trust referral system. I guess it still involves a moderator killing off bad nodes, but it seems to scale well

by geokon

6/2/2026 at 5:44:46 PM

> it seems to scale well

This seems hard to say without knowing how large it is. To me, it seems like a relatively small community, far smaller than HN anyway.

by usefulcat

6/2/2026 at 11:30:07 AM

yeah but I can't post there because I don't know anyone with an account and frankly CBA traipsing around looking for someone who has an account.

does seem like more things will have to go this way though

by dust-jacket

6/2/2026 at 11:39:46 AM

+1, if anyone wants to help me I'd be honored. mail me at ramon(@)odeva(.)nl

by ramon156

6/2/2026 at 1:33:10 PM

Blizzard's Real ID system would fix all of this. It was ahead of it's time /s

by Decabytes

6/2/2026 at 2:18:13 PM

> I think someone should start a community online where AI isnt allowed.

That's lobsters I guess. AI posts got banned there after a 300+ comment discussion, probably the biggest ever on the site.

The exact rule the moderators settled on was "meaningful human authorship" but don't be fooled: a lot of people on lobsters are ideologically opposed to LLMs. Doesn't matter how "meaningfully" the technology was applied. My work was classified as slop simply because AI touched it. People referred to me as an exhibitionist and fetishist when I talked about using AI. Just a heads up for anyone who's thinking of joining.

by matheusmoreira

6/2/2026 at 2:23:02 PM

on my way!

by crumpled

6/2/2026 at 4:23:18 PM

Ironically, the top comment (this) is now about AI.

by wmedrano

6/2/2026 at 11:40:43 AM

> a community online where AI isnt allowed.

This is something I think about a lot, especially how one could pull it off without tearing down anonymity online. Having some sort of "proof of humanity" is a hard problem to solve.

by 9dev

6/2/2026 at 1:09:42 PM

not really, you can just ask people to do a shit job identifying traffic lights and motorcycles and they'll do it.

by mr-pink

6/2/2026 at 10:41:55 AM

The amazing thing about AI is that you don’t even need AI superfans to shoehorn it into a conversation that doesn’t even touch on AI. Detractors will do it for them.

by DoughnutHole

6/2/2026 at 11:13:22 AM

Yes, it’s similar to Trump. But that makes sense right? AI is changing the world drastically, and so is Trump and his fascist friends.

by NuclearPM

6/2/2026 at 10:26:28 AM

> a new syntax

How is the syntax new?

It looks like lispy - see the outer parens in the examples given.

by shevy-java

6/2/2026 at 11:19:10 AM

Heh, every time you show a average developer lisp for the first time the reaction is the same. Little do they know conditionals, GC, REPLs, macros and more comes from the syntax and language dreamed up in the 50s/60s.

by embedding-shape

6/2/2026 at 12:26:14 PM

I don't see why Lisp's history would necessarily imply the family is worth learning in 2026. What (other than macros) do lisps offer that other modern languages don't?

by maleldil

6/2/2026 at 12:43:11 PM

You don’t program in Lisp, do you? I used to be confused by the smug Lisp weenies. Now I am one. And the difficult thing I’ve found over the years is that Lisp is sort of unexplainable. You either “get it” or you don’t. Yes, it has macros, but macros are a bit overrated. I’ve been programming in Lisp for decades and I rarely write macros. I think the thing that is difficult to convey is how powerful Lisp’s core execution environment is while at the same time being just a page of code that a CS undergraduate can understand. Literally everything else is a library. And those libraries can create syntax, generate code on the fly, and do many other powerful things. But most people won’t “get it” until they take the plunge. I didn’t. Until I did. And now, I don’t feel a need to defend Lisp at all. It won’t go away. You can’t kill it. The folks that “get it” will always have it, and those that don’t “get it” will reach for their Blub language again and again. Such is the way of the world.

by drob518

6/2/2026 at 5:30:49 PM

Getting lisp is analogous to spiritual enlightenment. If someone doesn't have the eyes to see and ears to hear, there's little you can do for them, except pray.

by frwrfwrfeefwf

6/2/2026 at 4:43:07 PM

Yeah, I didn't get it either until I implemented my own lisp.

> the difficult thing I’ve found over the years is that Lisp is sort of unexplainable

I've found that getting rid of the parentheses helps.

  f(x)
  (f x)
  ["f", "x"]

  (print (< 10 20))
  ["print", ["<", 10, 20]]

Lisp code is just normal Python lists which get evaluated by an interpreter function. Like this:

  code = ["print", ["<", 10, 20]]

  def eval(code):
      # magic

  eval(code)
  True

Filling out that eval function is a great way to learn lisp.

These articles are very good and accessible:

https://www.norvig.com/lispy.html

https://norvig.com/lispy2.html

by matheusmoreira

6/2/2026 at 3:40:12 PM

> You don’t program in Lisp, do you?

Not anymore. I started with Racket and went through the Little Schemer. I did Clojure for a while. I even used Babashka to write all my scripts, then later rewrote them in other languages.

I gave it a good try. Maybe it wasn't enough to properly "get it"?

by maleldil

6/2/2026 at 3:50:54 PM

Aw man I love babashka. I will say the lack of static types in clojure is pretty brutal for me. Especially when combined with the obtuse error messages. But I still love babashka and the whole REPL driven world.

What did you end up rewriting your bb scripts in?

by chamomeal

6/2/2026 at 3:56:32 PM

If there's one thing that I sometimes wish Lisp had, it's types. Most of the time, I don't need or even want them. But when you're doing a big refactor or changing the shape of your primary data structure, it would be nice to have the compiler be able to assist you in detecting locations where you've cross-wired something. But other than that, I don't care. And yes, Clojure's error messages could be better, but they have been getting better over time.

by drob518

6/2/2026 at 3:53:59 PM

That's a very reasonable try. Your statements are not unfounded. If I may ask, what's your daily driver now and why do you favor it over Lisps?

by drob518

6/2/2026 at 1:25:55 PM

There are reasons why not that many programmers “get it”, and it’s not because the others are uninformed. It’s a matter of valuing different things.

by layer8

6/2/2026 at 3:25:23 PM

Hmm, that'd be weird, how do you know you "value something different" if you haven't "got it"? You'd need to "get it" first, then you can understand if you value something different or not, otherwise how would you know?

by embedding-shape

6/2/2026 at 4:05:09 PM

The usual insinuation is that if you don’t like it, you “just don’t get it”. I meant not “getting it” in that sense.

by layer8

6/2/2026 at 2:46:59 PM

Absolutely! But it’s also because they don’t really understand one of the things. It’s the Blub Paradox.

by drob518

6/2/2026 at 1:31:49 PM

this is incredibly smug, but fun to read :) I briefly "got" Clojure but forgot again. Maybe I'll give this Janet thing a try.

by cdelsolar

6/2/2026 at 4:01:09 PM

LOL, indeed. Clojure is fun. I haven't used Janet, but I appreciate seeing some of the good ideas that it stole from Clojure (stealing being the sincerest form of flattery, and all that). IMO, one of Clojure's greatest gifts, above and beyond other traditional Lisps like CL and Scheme, is its focus on immutable data structures. When I started playing with Clojure, I was skeptical. I figured performance was going to be horrible. Now, I can't live without them. It's one of those subtle features that just changes how you program. It's one reason I choose Clojure over CL and Scheme today. Janet seems to have both mutable and immutable data structures, which is nice. Clojure has transients, but that's sort of partially mutable. That said, with Clojure, one of the nice things is that you can always drop back to Java's full mutability if you want, but that's obviously relying on the platform and not Clojure the language.

by drob518

6/2/2026 at 4:50:48 PM

S-expressions. Defining data in JSON or XML is way worse than S-expressions.

by evdubs

6/2/2026 at 4:37:20 PM

Just saying "macros" is a bit reductive: in CL, you have access to the full language at (read) parse time, compile time and runtime. Said macros also mean that logical OR/AND short-circuiting isn't a compiler black box, you can implement such behaviour easily yourself.

------

The syntax is actually a big pro for a lot of people. I love its streamlined look that basically reads like Python once you let your IDE indent properly and learn to see "through" the parentheses (CL, Scheme).

The original language where everything is an expression and it shows. Where Python still needs an ugly ternary and made match a statement, Lisp has had the perfect IF and COND since the dawn of time.

Symbols are still a cool and useful concept that almost no other language I know of got.

The numerical tower - despite some holes - is amazing. Built-in rationals and "correct math" as sane default (i.e. 1/2 not returning 0) never get old.

------

And if you let me rave about CL specifically (e.g. DECLARATIONs as "#pragma done well", restarts, CLOS/MOP, runtime READ/COMPILE, etc...), there are a lot of cool features barely copied anywhere that'd improve other languages, but these aren't part of "what make Lisp Lisp".

by BoingBoomTschak

6/2/2026 at 10:05:53 AM

It’s been a few months, but I built a tool by Janet lang to communicate with an LLM via HTTP. Of course, I probably had Claude Code write it for me. It turned out better than I expected.

I was really impressed by how small the executable file was. I’d only ever done web development with Node.js up until then.

by soomtong

6/2/2026 at 1:54:20 PM

I have my qualms with Janet. Mostly, it's lack of package management versioning and lack of libraries in general (advanced HTTP routing, etc).

I do LOVE that Janet can create binaries with JPM, scripts, and is very portable. I once put the Janet programming language on the Playdate game console as POC.

I actually do enjoy writing Janet, but every time I do people think I created the language (I did not).

by janetacarr

6/2/2026 at 5:44:34 PM

If you want server side, as veqq says there's joy which implements its own lightweight http server. If you want a client, it's quite trivial to use the Janet C API to wrap libcurl or any other HTTP client. If you're open to LLM development have the LLM write the wrappers and write your actual logic in Janet.

by Karrot_Kream

6/2/2026 at 5:44:55 PM

Have you tried jeep?

https://github.com/pyrmont/jeep/

It let's you vendor deps and easily install modern Janet bundles without jpm.

by ramblurr

6/2/2026 at 4:26:56 PM

> advanced HTTP routing

What do you concretely mean by this? I use https://github.com/joy-framework/joy for all web stuff and can probably get your missing features in within the week.

by veqq

6/2/2026 at 1:58:07 PM

Julia Evans has a fun blog post using Julia to visualize Gunzip: https://jvns.ca/blog/2013/10/24/day-16-gzip-plus-poetry-equa...

you should totally do a "Janet writes Janet" version

by FelipeCortez

6/2/2026 at 11:29:12 AM

There is also fennel, earlier language originally by same developer, that is similar, but compiles to, and is fully implemented in, Lua. No standard library of its own so missing many nice things like the parser library from janet, but it is good for writing scripts for things that embed Lua.

https://fennel-lang.org/

by 1313ed01

6/2/2026 at 1:48:17 PM

Fennel really is great, and a great way to get into the clojure family. My biggest gripe with it is that debugging is the typical transpilation bed of needles. The bridge between Fennel and the Lua VM is super fragile, and it just doesn't have half the quality of the Janet debugger and REPL. It's a real shame, because Fennel is way more portable, and thanks to LuaJIT is capable of breaking SBCL's jaw, which is absolutely fucking insane. But the transpilation experience just completely kneecaps it imo. There are workarounds you can do, but even if you mess around with implementing a debug.setinfo you still run into less-than-fun edge cases like with match-blocks.

I think there's a lot of value in forking LuaJIT2 and reworking the debugging and error structures within to make it more suitable for language transparency. Doing so would make languages like Fennel much more attractive.

by ux266478

6/2/2026 at 2:23:33 PM

> capable of breaking SBCL's jaw

What exactly do you mean by this? Speed? Portability? Ease of use?

by JHonaker

6/2/2026 at 4:55:55 PM

What I mean by that is that it's in the same weightclass of speed, depending on the problem being tackled. In the case where data's shape is mutable, SBCL will scream ahead thanks to CLOS. You can cheat LuaJIT with dynamically-defined C-structures via abuse of the FFI lib instead of native tables, but it's not as nice as CLOS nor is it very safe. In the case that the shape of data is changed extremely frequently? CLOS might actually end up falling behind here. Another area where SBCL will likely win out is when the hotpath is bottlenecked on string operations.

Where I'd say it advances into breaking SBCL's jaw is that the runtime, interpreter, jitter, etc. are all much smaller than SBCL's runtime and compiler. If you're looking for a complete system, I'd say SBCL wins out obviously. You're talking a world-class REPL, debugger, a high quality stdlib, etc. All it's missing is a text editor like LispWorks (emacs and pretty much every other FOSS Lisp editor I've seen is a massive downgrade.) With that in mind, SBCL is not something you embed in an application written in another language. The holy grail is getting something as fast as SBCL, as flexible as SBCL, but as a 50k loc self-contained runtime. LuaJIT is the reigning heavyweight champ there, so having a Lisp-adjacent language like Fennel running atop it is a pretty damn compelling idea.

Interestingly with regards to text editors, Lua doesn't have that problem technically. Lite-XL is dangerously close to being zmacs/LispWorks for Lua. Poetically, just like Lua it's fairly bare bones and requires extension to be a decent IDE. But the underlying structure is absolutely fantastic, being based around a fairly cohesive object model rather than coats of paint over text buffers.

by ux266478

6/2/2026 at 3:41:35 PM

Is fennel clojure-ish? I’m vaguely aware of it being a lisp, but I didn’t know it was clojure-ey. Pretty neat sounding!

by chamomeal

6/2/2026 at 4:29:36 PM

All new Lisps since ~2010 have been Clojure-y-: https://p.hagelb.org/new-lisps.html (Lone Lisp and LispE are the only exceptions and LispE still has _some_ Clojure features.)

by veqq

6/2/2026 at 10:42:57 AM

Always nice to see janet getting some attention.

shout out to one modern feature: sandbox

"Disable feature sets to prevent the interpreter from using certain system resources. Once a feature is disabled, there is no way to re-enable it."

https://janet-lang.org/api/misc.html#sandbox

by ramblurr

6/2/2026 at 12:30:51 PM

It's a really cool feature but what is a scenario when your average programmer needs such sandboxing?

by declan_roberts

6/2/2026 at 12:44:52 PM

I sandbox all my utilities and programs in case some compromised third-party dependency decides to run lose. It's a way to limit the blast radius.

by myaccountonhn

6/2/2026 at 12:53:41 PM

you're embedding it as a scripting api and want to limit permissions to just what's needed

by briaoeuidhtns

6/2/2026 at 1:29:55 PM

The TIC-80 game engine embeds Janet, and if i recall sandboxes the games created

by petee

6/2/2026 at 11:56:18 AM

The author made these using Janet (discussed on HN in the past):

https://bauble.studio

https://toodle.studio

Those two fascinating art tools got me very excited about Janet a while back.

by xrd

6/2/2026 at 12:25:08 PM

> SETQ is def

At first I said "what" out loud, since SETQ doesn't create bindings, it only updates them then I read the doc (https://janet-lang.org/docs/bindings.html) and the author is indeed wrong ("bindings created with def are immutable"). He probably meant "SETQ is set".

I really want to like Janet, as it seems to be the sweet spot between Guile, Tcl and CL (minus the speed/maturity of SBCL) but I have a visceral reaction to square brackets (so vectors) being used in lambdas and control flow operators. Same as Clojure, I simply can't get over it. Maybe I will with enough effort?

Also, what's the current LSP/SLIME status? Really important these days.

by a-french-anon

6/2/2026 at 12:42:20 PM

Square brackets’ use is very consistent and rather logical in how they are used in Clojure’s syntax.

When round brackets are used, the first element in the list defines how the rest of the list is interpreted, for example:

(func a b c) — run a function with its parameters

(macro x y z) — expand a macro with its parameters

([p q r] …) — “bare” function body that starts with a vector of parameters, and executable forms follow.

Square brackets are used where elements are the same “kind”, and the first one is not special, e.g.:

(defn f [a b c] …) — a collection of same-kind parameters, the first parameter is not special

(let [a 1 b 2] …) — a collection of bindings, the first binding is not special

The only exception that comes to mind is grouping multiple matching elements in `case`, but it for ergonomics.

Once I got the logic, when which is used, I changed my mind, and ever since I’ve felt it’s beautiful.

by nlitened

6/2/2026 at 1:36:15 PM

Thanks a lot, that's a very interesting way of seeing it.

by a-french-anon

6/2/2026 at 4:06:10 PM

You can... just not use square (and curly) brackets. Instead of `[1 2 3]` just write `(array 1 2 3)`. Instead of `(fn [x] (+ 1 x))` just write `(f (x) (+ 1 x))`. They are never necessary.

by veqq

6/2/2026 at 4:39:36 PM

Huh! So like some Schemes and Racket? Yet I must read them in code that isn't mine, which is a large part of the problem.

by BoingBoomTschak

6/2/2026 at 12:07:15 PM

janet has replaced sh, python, awk, etc. for me, for system scripts over a certain length! it has a very fast startup time (on my system, 1.4ms via hyperfine vs. 1ms for dash) for scripts (not compiled executables), and its sh-dsl module allows typing shell commands very elegantly, like ($ cmda w x | cmdb y z). the ability to load an image to debug is a big help, too. i've started using it very recently but it's probably one of my favorite languages now, and the only other lisp i've used is mit scheme for sicp.

by mackeye

6/2/2026 at 11:59:13 AM

This document was really helpful when I first met Janet:

https://janetdocs.org/tutorials

https://janet.guide/ (the author's one)

by soomtong

6/2/2026 at 4:18:50 PM

I'm really happy you liked it! It's still a work in progress.

by veqq

6/2/2026 at 10:01:29 AM

> But by allowing you to unquote literal functions, Janet makes it possible to write macros that are completely referentially transparent.

These lisp guys really get excited over very abstract things. If you say this to an average person on the street they will probably try to run away.

by uka

6/2/2026 at 11:52:34 AM

> very abstract things

A C macro with literals that lacks referential transparency:

  #define MULTIPLY(x, y) x * y
  int result = MULTIPLY(2 + 3, 4); // 14

Not knowing what something means does not make it bad, which is what I'm assuming you meant given how you phrased your sentence.

Having a shared language of patterns and problems that occur in programming is a good thing. Ridiculing such terminology on the basis of "that group of programmers sure are weird" is pointless and counter productive.

by fredrikholm

6/2/2026 at 3:29:14 PM

Thank you for the lesson. Very productive of you and on point.

Now if you relaxed just a little bit - the world would be much nicer place.

by uka

6/2/2026 at 10:03:50 AM

you ever try to explain object oriented programming languages and their benefits to the "average person on the street"?

by bryanrasmussen

6/2/2026 at 10:06:54 AM

somehow i also never got the idea around these languages like lisp. I remember i studied them in school - but i quickly forgot and never got around to relearning it.

by rambrrest

6/2/2026 at 11:15:01 AM

It took me probably 5 years of writing Clojure before it clicked. Once you get used to structural editing and repl driven development, it’s really hard to go back to syntactic languages.

It’s kind of like in treesitter style editing, where you can “swap these two arguments,” “select this function,” “wrap this in a try block” with a single keyboard command… but way more standardized and granular. Plus with the ability to execute anything you highlight

All that and then you realize you can store code as data (since it’s just a data structure) and run data as code.

I think most programmers don’t realize how arbitrary the difference is between code and data until they get used to using LISP.

by barrell

6/2/2026 at 12:53:59 PM

Spot on. For me, it clicked with Common Lisp, 15 years after I graduated from university. Now, Clojure is my daily driver. And it’s extremely difficult to explain to people. I’ve gotten to the point where I don’t even try. You’re right about all the things you mentioned. Once you discover structural editing, everything else seems primitive, on the level of cavemen playing with rocks. But it’s not just one feature that makes Lisp better. It’s all of it which interrelates and creates a powerful synergy (I hate that word, but in this case it’s appropriate) that just isn’t matched by anything else. There are other languages that have a similar vibe, notably Forth and Prolog, but they are often misunderstood, too. Honestly, that’s my real test of whether someone is a senior programmer: do they understand and at least have an appreciation for these languages, even if they don’t program in them everyday.

by drob518

6/2/2026 at 10:24:41 AM

The idea is that instead of having to learn tens of different syntactic constructs with subtle and often arbitrary differences, you just have parentheses and use them to build everything.

by xigoi

6/2/2026 at 11:14:55 AM

This is such a undervalued benefit, once you've learned s-expressions, you can basically learn a bunch of languages without having to learn completely new syntax. It'll be slightly different, with different idioms and names, but a hell of a lot easier than doing the same across every "It's like C but 50% of the syntax is different actually" language out there, which is most of them.

by embedding-shape

6/2/2026 at 11:53:10 AM

Is the syntax really the stumbling block for most languages? Would Rust's lifetimes or Swift's isolation rules be easier if they used more parens? Are the scoping rule differences between Emacs Lisp and Scheme easier to comprehend because the syntax is similar?

by jurip

6/2/2026 at 12:19:46 PM

Yes, a commonly occurring stumbling block for me is trying to use one language's syntax while actually programming in another, especially when it comes to all the Algol/C-like language, I probably mix things on a daily basis.

The concepts would be easier to grok up front if they just used normal function calls instead of "And now for this special syntax that only exists for this particular feature" which just adds more things to remember, instead of just the concepts themselves.

by embedding-shape

6/2/2026 at 12:30:27 PM

Yes it is, because as soon as programmers step out of the most basic language level (which is kinda similar in most mainstream languages) there's a bunch of wildly different concepts, with wildly different ways of writing them. Writing them in isolation might be manageable, but it's combining them effectively that gets hairy very quickly, unless one is very experienced in said language. But then, translating that to OTHER languages becomes a bar that is too high!

by dragandj

6/2/2026 at 5:18:18 PM

[dead]

by iLemming

6/2/2026 at 1:30:51 PM

That just moves the subtle and often arbitrary differences to the functions and macros you use.

by layer8

6/2/2026 at 1:51:32 PM

The kind of subtle difference I’m talking about is that in C, you have to put a semicolon after struct {…} and do {…} while (…), but not after other curly brace constructs. What would be the analogue in Janet?

by xigoi

6/2/2026 at 2:27:14 PM

The first one is pretty C-specific and for example doesn’t exist in Java. Similarly for the second one, the reason is that `while` is used for two different constructs, which for example isn’t the case in Rust. These are just accidental complexities stemming from unfortunate design decisions in C. Having a richer repertoire of syntactic constructs doesn’t by itself imply such complications.

My point was, replacing n syntactic constructs by n functions or macros doesn’t reduce the cognitive load of having to know how each construct works. To the contrary, one can argue that everything having the same syntactic form makes it more difficult to distinguish different classes of features.

by layer8

6/2/2026 at 2:44:25 PM

> The first one is pretty C-specific and for example doesn’t exist in Java.

It was just an example, most languages have quirks like this. I don’t know about Java, but in Rust you have the turbofish operator, whose necessity stems from using the less-than sign as both an operator and a delimiter.

> My point was, replacing n syntactic constructs by n functions or macros doesn’t reduce the cognitive load of having to know each of them.

The difference is that if you don’t know a function/macro, you can just read its documentation. If you don’t know a syntactic construct, where do you look?

Another advantage is that if you want to create new functionality similar to existing language features, it won’t stick out like a sore thumb. For example, you could create an until loop:

  (until (window-should-close)
    (draw-screen))
  # is equivalent to
  (while (not (window-should-close))
    (draw-screen))

In Rust, it would have to look completely different from a while loop:

  until!(window_should_close(),
    draw_screen());
  // is equivalent to
  while window_should_close() {
    draw_screen();
  }

by xigoi

6/2/2026 at 10:30:45 AM

Probably depends on whom you are asking. For me the essence is (1) having functions or procedures as the basic building blocks, not classes. (2) Having all the utility and higher order functions you need to deal with the functions and procedures first idea. (3) Having a very powerful syntax, that allows great semantic editing and is never ambiguous. Oh and can actually be extended in useful ways, without having to wait for a committee to decide upon "the one syntax to rule them all".

by zelphirkalt

6/2/2026 at 4:35:26 PM

> can actually be extended in useful ways

I just made a library with [query syntax](https://codeberg.org/veqq/declarative-dsls) over various data structures a la sql:

    (import declarative-dsls/dataframes :as df)
    (def people (df/dataframe :name :age :job))
    (df/dataframe? people)

    (df/insert! {:name "Bob" :age 30 :job "Developer"} :into people)
    (df/insert! {:name "Alice" :age 27 :job "Sales"} :into people)
    (df/update! :set {:job "Engineer"}
             :where |(= ($ :job) "Developer")
             :from people)
    
    (df/save-csv people "people.csv" :sep "\\t")
    (def people2 (df/load-csv "people.csv" :sep "\\t"))
    
    (-> people2
       df/dataframe->rows
       df/rows->dataframe
       df/print-as-table)

Printing:

    job       age  name
    --------  ---  -----
    Engineer  30   Bob
    Sales     27   Alice

It also has datalog and minikanren (with s expr, sharing the same goals etc.) And it vectorizes like APL:

    (df/v + [1 2 3] 1 [1 2 3] 1) # returns: [4 6 8]
    (df/v + 1 {:column [1 2 3] :key [1 2 3]}) # returns: {:column @[2 3 4] :key @[2 3 4]}

    (df/v * [1 2 3] [[1 1 1]
                     [1 2 2]
                     [1 2 3]]) # returns: @[@[1 1 1] @[2 4 4] @[3 6 9]]

Or you can just use [J directly from Janet](https://git.sr.ht/~subsetpark/jnj):

    (jnj/j "3 4 $ i. 10") # returns: ((0 1 2 3) (4 5 6 7) (8 9 0 1))
    (jnj/j "$" [3 4] (range 10)) # returns: ((0 1 2 3) (4 5 6 7) (8 9 0 1))

The Joy Web Framework has a cool [db query dsl](https://github.com/joy-framework/joy/blob/master/docs/databa...) too: `(var account (db/find-by :account :where {:login (auth-result :login)}))`, used for a [web auth](https://codeberg.org/veqq/janetdocs/src/commit/848dcbd8e54ad...).

From my response, bigger than the article: https://lobste.rs/s/y0euno/why_janet_2023#c_lspe6n

by veqq

6/2/2026 at 12:16:12 PM

Pretty straight-forward, as the world as we perceive it is made of objects with attributes, interacting with each other via their methods. OOP easily fits the brain of the average person in the street.

by skeledrew

6/2/2026 at 12:54:17 PM

[dead]

by the_af

6/2/2026 at 5:37:24 PM

> over very abstract things.

I beg to differ. There's just isn't "easy and straightforward" path to simplicity. We thought that explaining the world with "objects" was simple and instead of using already existing language, OOP took "objects" (an easy choice) and invented a elaborate taxonomy of "patterns" to work around the limitations of objects. Just look at this mess:

- Strategy Pattern: Interface + multiple classes + dependency injection + factory maybe. Bruh, it's just a function that takes a function.

- Singleton: Private constructor + static instance + thread safety + double-checked locking. Bruh, it's a fucking value. You define it once. It doesn't change. You're done.

- Observer/Event System: Interface + listener registration + event loop + memory leak when you forget to unsubscribe. Bruh, tis a fucking function applied to a list (or stream).

- Decorator; Wrap a class in another class that implements the same interface. Bruh - it's function composition. You learned this in algebra class before you turned fourteen.

- Command: Encapsulate a method call as an object with execute(), undo(), history queue... It's a function stored in a variable. That's it. That's the pattern.

- Factory: Separate class whose entire job is to call constructors. Come on, it's just a fucking function.

- Template Method: Abstract base class with a method that calls abstract methods subclasses must override. It's a higher-order function.

- Iterator: Interface with hasNext() and next(), mutable state, ConcurrentModificationException. It's fucking map.

The Gang of Four book exists because Java made functions second-class citizens, so programmers spent 20 years building elaborate object scaffolding to simulate... functions. FP didn't solve these problems. It just never had them.

Yet somehow the industry likes to pretend that every programmer knows (or should know) OOP, while keep telling everyone how hard programming is.

Those who found the truth understand that there's a reason why Lisp just refuses to die and it's unlikely it ever will. At 70 years, it is still flourishing.

by iLemming

6/2/2026 at 10:53:45 AM

Average programmer too /j

Frankly, though, I think lispy community has benefited from being smaller. For example, even though the now ancient Design Patterns already warned programmers to prefer composition over inheritance, the OO programmers still created 15 levels deep hierarchies.

by prerok

6/2/2026 at 1:01:12 PM

> These lisp guys really get excited over very abstract things. If you say this to an average person on the street they will probably try to run away.

Referential transparency is a funny name for a very powerful feature which helps you understand what the program does better, it's not a deeply abstract thing. Don't let the name scare you.

You could ask "why the funny name"? Well, specialized professionals use specialized jargon, even for "normal stuff". It's unreasonable to expect otherwise. Car mechanics also have weird names for car parts that are absolutely essential for the car and not that hard to understand if they explained them to you.

by the_af

6/2/2026 at 10:17:45 AM

I've been drawn into the Janet posts that surface every once in a while here on HN, but found the otherwise highly praised "Janet for Mortals", not being for mortals at all.

by wodenokoto

6/2/2026 at 4:20:35 PM

I have some gentler introductory stuff like: https://janetdocs.org/tutorials

by veqq

6/2/2026 at 10:53:17 AM

> I've been drawn into the Janet posts that surface every once in a while here on HN, but found the otherwise highly praised "Janet for Mortals", not being for mortals at all.

I'm surprised: the language is very straightfoward, simple, very few rules to remember. It's a Lisp but with a very small surface area.

I mean, compared to other languages, Janet really is easier to lean, so I'm surprised that the book for it is difficult (did not read the book, but familiar-ish with the language. I don't have anything but praise for it, TBH).

by lelanthran

6/2/2026 at 11:14:52 AM

Personally I get hung up on the macro syntax being near the beginning, but there is so much valuable stuff past that

by petee

6/2/2026 at 10:27:09 AM

> not being for mortals at all.

I had that with Haskell. Although, while Haskell is too hard for me, I actually like its syntax.

Janet seems to be Lisp 2.0, so the syntax is lispy.

by shevy-java

6/2/2026 at 10:42:44 AM

Seems some of the listed advantages for Janet would also apply for tcl (small/simple, easy to learn, embeddable, usable as a shell, great for domain specific languages). It would be interesting, to me at least, to see a fan of Janet compare the two.

by 0x0203

6/2/2026 at 11:21:52 AM

I've only used Tcl briefly, mostly for automation which it's great at. But it's a Algol-like imperative language, doesn't have any type of macros and makes everything based on strings (which makes sense for automation) instead of lists, with all the tradeoffs that comes with.

It seems easier to figure out what the similarities are, because I think they're pretty few, they seem to differ more than they are similar.

by embedding-shape

6/2/2026 at 1:23:20 PM

Tcl being based on strings creates the same problems like in bash scripts, i.e. it is too easy to misuse the quotation rules, leading to subtle bugs.

Using for scripting LISP-like languages is much more foolproof, especially for more complex scripts.

by adrian_b

6/2/2026 at 2:28:07 PM

Ok, but now I want to embed Janet in a TCL program

by packetlost

6/2/2026 at 1:34:34 PM

Janet is faster, but lacks anything like tk. It's probably also quicker to learn, as you don't get into complex evaluation structure until you start messing around with quasiquotes, while tcl requires you to understand mixing 3 different layers of evaluation right off the bat. tcl's vm imo is easier to understand as well.

tcl if you want a UI, janet if you want an embedded scripting language.

by ux266478

6/2/2026 at 5:30:20 PM

DSLs. Creating a language that only you know that will double the learning curve for the folks coming after you. It's fine for personal projects, but almost always an anti-pattern.

by doug_durham

6/2/2026 at 1:24:47 PM

The author does not mention that Janet comes with _built-in_ networking

Having tried many tiny interpreters over the years, that's relatively rare IME

by 1vuio0pswjnm7

6/2/2026 at 4:57:07 PM

Wow I never realized Janet was released more than 10 years after Clojure.

Clojure: 2007

Janet: 2019

by didibus

6/2/2026 at 10:01:36 AM

This got me thinking of Hy. I wonder how syntactically close they are; there might be an exploitable Python -> Hy -> Janet path here.

[0] https://hylang.org/

by skeledrew

6/2/2026 at 3:20:06 PM

I use both. They're similar for simple use, but above a certain level of complexity Hy has a lot of Python-isms that bleed through. It really doesn't ever let you forget that underneath all the parentheses you're really writing Python. Janet feels like its own stand-alone language in that respect, where Hy is more like a syntax swap.

I have the impression that Hy's user base is larger, though (not that either one is huge).

by cfiggers

6/2/2026 at 10:18:05 AM

I used Hy for a long time, then tried Janet, and ultimately realized that I wanted more batteries included but didn't want Python... So I forked https://github.com/rcarmo/go-joker and am tinkering with it until it does all I want.

by rcarmo

6/2/2026 at 10:06:32 AM

Previously (April 2023) | 140 comments: https://news.ycombinator.com/item?id=35539255

by defrost

6/2/2026 at 11:34:43 AM

Does embedding Janet still lean on global state?

by AHTERIX5000

6/2/2026 at 2:49:39 PM

My first question too, and I checked out the linked book [1], and sure seems like it! There's global functions like `janet_init()` and `janet_loop()` all over the place.

A language shouldn't advertise itself as "embeddable" if it does this. It means you can't have multiple interpreters, you can't use it on multiple threads, etc. GNU Guile does this too, and it's a baffling decision! For my field (audio plugins like VSTs), it means it's absolutely a no-go, because hosts can load any number of instances of your plugins and potentially run them in parallel in the same address space, they can't rely on global state like this. Each interpreter has to be separate.

Lua does this right, as does Python (as of 3.12, when they made the GIL local to each interpreter) and I think most of the JavaScript engines. And it's not hard, instead of a global `janet_init()`, just have an opaque pointer bundle all the state, like `janet_init(interpreter)`. If you want a global interpreter, just stick it in a global variable.

[1]: https://janet.guide/embedding-janet/

by OskarS

6/2/2026 at 3:48:27 PM

Janet global state is thread local;[1] janet_init() is called once per thread.

[1] official docs: https://janet-lang.org/capi/embedding.html

by petee

6/2/2026 at 12:18:11 PM

Thought this might be about JANET, the rationale for which I have never really understood. The wikipedia article on it is not very explanatory: https://en.wikipedia.org/wiki/JANET

by zabzonk

6/2/2026 at 10:03:18 AM

> Instead of regular expressions, Janet’s text wrangling is based around parsing expression grammars. Parsing expression grammars are simpler, more powerful, and more predictable than regular expressions.

I would dispute that this is the case. In PEGs, alternatives are not commutative, unlike in regular expressions. This can lead to quite frustrating debugging. While a valid choice, the advantage over REs is overstated.

by lindig

6/2/2026 at 3:43:13 PM

I'd argue they are not commutive in regexes either, at least as implemented in practice. Implemented regexes favor the leftmost alternative even when both sides of the alternative match. This matters in cases like: capturing groups, and backtracking implementations. There absolutely are cases where one ordering of alternatives could yield catastrophic backtracking for some input, while the other will avoid it completely.

I personally don't like this at all. This means that regex engines that try to generate optimized matching code for an expression can end up generating suboptimal code if you don't want alternative order to matter, since the engine needs to keep that invariant, except in the case when it can prove that the alternatives won't overlap, and a later one can be checked in constant time. If both are true, it is legal to reorder them to do the constant time check before the big complicated wildcard-filled alternative.

But personally, I have never written a regex where I actively cared about the alternative evaluation order. I've used some other people made where order is important but never written one myself.

I'd love to be able to tell the engine "feel free to swap the evaluation order of my alternatives while optimizing", but few if any such engines offer that as a feature.

Now I get that PEGs have commutivity problems are that are different from regexes', which make the issue worse, but that doesn't mean regexes do things right either.

by jsmith45

6/2/2026 at 10:59:22 AM

The non-commutavity is a feature, not a bug. It allows you to have clearly defined parsing for grammars that would traditionally be considered ambiguous.

by xigoi

6/2/2026 at 1:37:05 PM

But that’s not how humans writing code generally think about ambiguous expressions. You can see that by how few precedence rules programmers tend to internalize, and often prefer extra parentheses to make sure that the parser interprets it the way they mean.

by layer8

6/2/2026 at 3:21:09 PM

I am not talking about operator precedence, that’s a separate thing. Consider the parsing of math expressions, where juxtaposition of terms denotes multiplication unless it can be interpreted as something else. So f(x+2) is function application, whereas 3(x+2) is multiplication. With a PEG, you just write a standard expression grammar with an additional choice at the end for the implicit multiplication. With a conventional parser, this is much more difficult – you have to explicitly list all the different ways that terms could be next to each other without meaning something else.

by xigoi

6/2/2026 at 10:41:09 AM

PEGs are just soooo much easier to read than regexes for anything more complex than a few words or single line matching. REs are a hammer that tempts people to see everything as a nail, but once one progresses beyond that phase one usually wants as few REs as possible.

by zelphirkalt

6/2/2026 at 1:40:15 PM

That’s mostly an artifact of concise regex syntax I believe. When you write regular expressions in an ABNF-like form, they become much more intelligible.

by layer8

6/2/2026 at 11:13:57 AM

"small peg tracer"[1] is really helpful for breaking down a PEGs operation

[1] https://github.com/sogaiu/small-peg-tracer

by petee

6/2/2026 at 10:30:55 AM

Came here for this comment. Janet would score positively in my mind if the evolutionary dead-end PEG were replaced with a grammar parser that is known to work under all circumstances.

by bmn__

6/2/2026 at 10:05:48 AM

Maybe needs a (2023) in the title?

by 6LLvveMx2koXfwn

6/2/2026 at 1:50:21 PM

The shell DSL is what made me want to try Janet

by hlude

6/2/2026 at 4:22:48 PM

We recently migrated to a standard library version: https://janet-lang.org/1.41.2/spork/api/sh-dsl.html

by veqq

6/2/2026 at 10:01:49 AM

The embeddability sounds very appealing. Does anyone have experience with using this somewhere one might traditionally reach for Lua?

by gspr

6/2/2026 at 10:26:59 AM

I have built a markup language with embedded scripting in Janet. I originally tried to use Lua, but found the verbosity extremely frustrating.

by xigoi

6/2/2026 at 1:44:05 PM

if those are the reason why you love janet, then you will love tcl because you will be able to do all the same things without drowning in parenthesis and weird syntax.

by boltzmann64

6/2/2026 at 5:14:05 PM

There are three languages worth learning that expand your mind: Lisp, Forth and Tcl. Despite all exhibiting homoiconicity, they couldn't be more different from one another.

(I'd include Rebol but it's as mind-blowing as it's dead technology from a lost timeline)

by sph

6/2/2026 at 3:14:30 PM

Dammit, Janet, I love you!

by WalterBright

6/2/2026 at 9:47:46 AM

Pretty compelling, especially "Janet does not adhere to the ancient customs. CAR is called first. PROGN is called do. LAMBDA is fn, and SETQ is def." - a sign of good sense for sure!

How fast is it?

Also my main objection to Lisps is still the horrible bracket syntax. Yes it's unambiguous and easy to parse, but it's HORRIBLE to read and edit. I wish this project had been a success (or something similar to it): https://readable.sourceforge.io/

Also I don't think static typing is really optional for me at this point.

by IshKebab

6/2/2026 at 11:27:37 AM

Actually not all those are ancient customs, and not all that Janet uses is newer.

In the first description of the language LISP, from March 1959 (AIM-008), John McCarthy had used the names "first" and "rest", instead of what later will be called "CAR" and "CDR".

The names of "CAR" and "CDR" appear to have come from the students who worked at the practical implementation of the LISP interpreter on an IBM 704, and unfortunately we have remained stuck with them, like also with other features that were intended only for a temporary use, until being replaced in the "final version" (which was abandoned).

by adrian_b

6/2/2026 at 10:01:49 AM

> Pretty compelling, especially "Janet does not adhere to the ancient customs. CAR is called first. PROGN is called do. LAMBDA is fn, and SETQ is def." - a sign of good sense for sure!

Just FYI, many of these are also done in Scheme and its derivative Racket. They kept lambda (but even Python did that), but progn -> begin, setq -> set!, car -> first, and so on.

> Also my main objection to Lisps is still the horrible bracket syntax. Yes it's unambiguous and easy to parse, but it's HORRIBLE to read and edit.

I have pretty mixed feelings at this point. I don’t mind it for normal programming, but when I do numerical programming (physics models, etc.) you often get extremely long and verbose expressions that are IMO difficult to parse compared to the math-like infix operator notation used in other languages.

by setopt

6/2/2026 at 10:07:56 AM

I'm starting to prefer the s expression syntax when dealing with tree structures like json.

I wonder if we were raised on tree based algebra if math would be easier to do, or harder.

Like, solve for x.

   (= (+ (* 2 x) 3) 11)
   (= (* 2 x) (- 11 3))
   (= (* 2 x) 8)
   (= x (/ 8 2))
   (= x 4)

Though this isn't too bad.

    (= (+ (pow x 2)
          (pow y 2))
       (pow r 2))

by aeonik

6/2/2026 at 1:15:23 PM

I think also a lot of my objections could be worked around if one simply had a "math" macro that evaluates infix math notation as a DSL, similarly to how the CL "loop" macro does a DSL for iteration.

Perhaps this exists already somewhere?

by setopt

6/2/2026 at 5:44:11 PM

> exists already

The helloworld of macros lets you do `(infix 1 + 2)`:

    (defmacro infix [a op b]
      ~(,op ,a ,b))

A useful one with precedence letting you to `(infix 2 + 4 * 5)`:

    (defmacro infix  [& toks]
      (def prec {'+ 1 '- 1 '* 2 '/ 2 '% 2})
      (var pos 0)
      (defn climb [min-p]
        (var left (toks pos))
        (++ pos)
        (while (>= (get prec (get toks pos) -1) min-p) # nil/operand -> -1, stops the loop
          (def op (toks pos))
          (++ pos)
          (set left ~(,op ,left ,(climb (inc (prec op)))))) # inc => left-associative
        left)
      (climb 0))

But ultimately, APL notation is best: https://git.sr.ht/~subsetpark/jnj

by veqq

6/2/2026 at 1:13:56 PM

I definitely prefer s-exps over both xml and json myself too!

Interesting question. Much of the difficulty does stem from mentally translating back and forth between conventional notation and s-exps too, since you can’t really avoid the standard notation when reading and writing math and physics papers. And current-day math and physics notation has been optimized to some extent for the infix notation; perhaps one would have invented more expressive higher-order functions or macros to denote s-exp math if that was what everyone used for centuries.

by setopt

6/2/2026 at 2:07:18 PM

If you ever used an RPN calculator then this is very familiar

by krupan

6/2/2026 at 2:26:19 PM

All programming languages have horrible syntax (except maybe Forth). Some examples:

Statements are terminated by either a dedicated graphical character, in which case it's easy to forget the character and have a problem, or by a newline (or maybe a different white space character, but I haven't encountered that yet) in which case decent formatting of code may require a dedicated graphical character to indicate that the newline DOESN'T terminate the statement, in which case we have the same problem. Having newline-terminated statements without continuation character would be consistent, but would hamper readability because identifiers would need to be strictly limited in length to keep certain lines from exceeding available screen space (or alternatively readability would suffer from lines only being partially readable).

And that's before getting into the weeds of how mathematical notation is tricky (most people have learned infix notation at maths class in school, so they mightn't appreciate how horrible it is), how different types of brackets (round, square, curly) can have inconsistent semantics, the downsides to the various ways of indicating lexical blocks (brackets, white space, keywords,...), et cetera.

The ideal programming language would probably be one which allows switching between different syntaxes based on what works best for the user (for example, someone could write code in S-expressions, another person could have that code automatically translated into SRFI-119 Wisp expressions and work with it like that, a third person could then have it rendered into something more Lua-like,...). Which is something I think the Racket people are working on, but I may be mistaken.

by tmtvl

6/2/2026 at 10:06:10 AM

Syntax is not that important to me. I prefer Python style indentation, but its really not that important - its just something to get used to for me.

Is static typing that important for a scripting language? From the intro to the book:

> And to be clear, I’m not going to try to convince you to bet your next startup on Janet, or even to use it in any sort of production setting. But I think it’s an excellent language for exploratory programming, scripting, and fun side projects.

by graemep

6/2/2026 at 2:39:42 PM

It's a scripting language, so it's not going to compete with anything compiled or JITed, but it has a pretty efficient threaded bytecode interpreter (that is almost more interesting than the language itself!). It's certainly good enough for most situations where you would reach for a scripting language.

by packetlost

6/2/2026 at 5:28:43 PM

AoT/JIT compilation is a property of the implementation, not the language.

It would be good to know order of magnitude anyway. Like, are we talking Ruby/Python level, etc.

by IshKebab

6/2/2026 at 5:36:01 PM

In my tests, it's 5-10x Python for long running things (about 30% slower than Fennel on LuaJit) but for small things, because you can easily shift work to compile time, it beats normal Go: https://codeberg.org/veqq/verse-reader#performance

by veqq

6/2/2026 at 11:12:14 AM

> Also my main objection to Lisps is still the horrible bracket syntax. Yes it's unambiguous and easy to parse, but it's HORRIBLE to read and edit.

I use Parinfer, which allows me to edit Janet as if it was an indentation-based language.

by xigoi

6/2/2026 at 12:20:04 PM

Yeah I mean I guess if you have to use that syntax, it's nice to have a better editor for it. But IMO the existence of that tool clearly demonstrates that the syntax is pretty bad.

by IshKebab

6/2/2026 at 1:00:14 PM

All C-derived languages (e.g. Java and Rust) have a bad syntax, with tons of superfluous parentheses and many other superfluous tokens, like semicolons or commas.

This normally matters very little, because a good editor will always insert a complete template whenever you type something like "if", "for", "while" etc.

Most programmers are blind to the syntax defects with which they are accustomed and they notice only the syntax defects with which they are unfamiliar.

I would prefer a language with a good syntax, but unfortunately which programming languages have survived in widespread use has a poor correlation with the technical qualities of a language and especially a really negligible correlation with how good its syntax was.

by adrian_b

6/2/2026 at 12:36:37 PM

Most editors manage your indentation, parentheses and braces for you. Not sure how that is a unique marker for lisp style languages.

by imtringued

6/2/2026 at 1:29:11 PM

> How fast is it?

Roughly as fast as puc-rio Lua. It won't blow your socks off, but it's more than respectable.

by ux266478

6/2/2026 at 11:31:37 AM

Out of those renames, I agree with car->first and progn->do. setq is ugly, but I think using def is maybe questionable. lambda I would have just kept the same.

by zelphirkalt

6/2/2026 at 10:26:03 AM

Are you aware of:

https://docs.racket-lang.org/sweet/index.html

by e12e

6/2/2026 at 12:33:41 PM

Janet is ALMOST an incredible tool...but what I want is a very clear bifurcation between the standard library's stateful mutating procedures, and stateless value-returning functions. I ran into that wall hard trying to make something non-trivial.

It also turns out that the mix is due to the standard library leaning on raw C loop iterations underneath whenever it can. Which is great! But it confuses the library's interface paradigms.

by netbioserror

6/2/2026 at 10:53:06 AM

Luxferre.top has some Janet based softwrae.

by anthk

6/2/2026 at 10:30:59 AM

Excellent. Although I suspect the author of the programming language invented this Janet for all the perfect puns. Yes, Janet. No. Janet.

by makach

6/2/2026 at 1:56:24 PM

Damn it, Janet. No proper namespaces. Hard pass.

by bjourne

6/2/2026 at 4:43:54 PM

> I never thought it could happen to me.

But I am truly biased. I have basically forgotten how to code everything else (besides APL family languages) in the past _checks notes_ 10 months since I started Janet. I even run a community [docs site](https://janetdocs.org/) and am writing [my own tutorial](https://janetdocs.org/tutorials/learn-to-program) (albeit slowly). I even use it in production for all new software (within 3 weeks of starting, I had rewritten all personal scripts etc.)

> Janet is simple

You can do literally everything with just hashmaps. The whole language is basically a hashmap, implementation wise. `(keys (curenv))` prints out all locally defined symbols. `(keys (getproto (curenv)))` prints the parent hashmap of the current environment i.e. all the core symbols. I don't, but you can basically do CLOS via hashmaps (and there is a [fuller implementation](https://git.sr.ht/~subsetpark/fugue) too.)

> Janet is distributable

I have like 20 websites and another dozen or so services running on Janet (with the [Joy webframework](https://github.com/joy-framework/joy) which I wrote a [tutorial](https://janetdocs.org/tutorials/Joy-Web-Framework) for), on a single free-tier VPS with 512mb of RAM.

> Janet has ... immutable collections

...not really. In reality, the whole standard library constantly returns mutable versions from everything. There's no reason to really try to be immutable at this point. Although there are cool [combinator libraries](https://git.sr.ht/~subsetpark/apcl-janet) and I've even made combinatorish versions of basic functions:

    (defn better-cond
      [& pairs]
      (fn :bc [& arg] # names for stack traces
        (label result
               (defn argy [f] (if (> (length arg) 0) (apply f arg) (f arg))) # naming is hard
               (each [pred body] (partition 2 pairs)
                 (when (argy pred)
                   (return result (if (function? body)
                                    (argy body) # calls body on args
                                    body)))))))

Combinatory inspired cond, which allows for pairs. The test does not need an argument and the body may be a simple value or a function:

    (map (better-cond
             string? "not a number"
             odd? "odd"
             even? "even") 
      [1 2 3 "cat"]) # the args!
    (map
        (better-cond
         1 (fn [arr] (array (min ;arr) (max ;arr)))) # (recombine array (unapply min) (unapply max)))
        (partition 2 (range 10))) # these are the args!
    ((better-cond
          < "first is smaller"
          > "second is smaller")
         5 3) # these are the args passed into the func! I am excited!

> Janet lets you pass values from compile-time to run-time

That's what got me hooked, in a few ways. In Racket or Go, I had to do a lot of work to process data at compile time so the runtime could literally just be a lookup table. In Janet? That's the default behavior of any `def` outside of main. The following turns a .tsv of the bible into a hashmap in the binary, when compiling:

    (def verses  (reduce (fn [acc line]
                           (let [parts (string/split "\t" line)]
                             (if (= (length parts) 5)
                               (let [[_ abbrev ch vs text] parts]
                                 (put-in acc [abbrev ch vs] text))
                               acc)))
                         @{}
                         (string/split "\n" (slurp "kjv.tsv"))))
    
    (def abbrev-array (keys verses)) # also makes an array of the abbreviation column

So the rest of the program is literally just accessing the hashmap ([twice as fast](https://codeberg.org/veqq/verse-reader#performance) as the Golang version using `embed`):

    (defn main [_ & args]
      (if (or (empty? args) (= "-h" ;args) (= "help" ;args))
        (do (print "Usage: kjv <book> [chapter:verse]") (os/exit 1))) # show help
      (let
       [Capitalized (string (string/ascii-upper (string/slice (first args) 0 1)) (string/slice (first args) 1))
        book        (find |(string/has-prefix? $ Capitalized) abbrev-array)]
    
        (pp (match args
              [_ chap verse] (get-in verses [book chap verse])
              [_ unsure]     (match (string/split ":" unsure)
                               [chap verse] (get-in verses [book chap verse])
                               [chap]       (get-in verses [book chap]))
              [_]            (verses book)))))

The equivalent go program was 5x longer and required an extra program to convert data into a 40k line .go file with a giant literal hashmap, to be faster than the naive Janet.

...but actually Ian Henry means Janet e.g. keeps closures synced across images/sessions:

    (defn timer [t] 
      (var t t) # this is slightly annoying, must shadow as params are immutable
       [(fn [] (set t (+ t 1)))
       (fn [] (set t (+ t 2)))])
    
    (def tx (timer 0))
    # call like this:
    ((tx 0))
    ((tx 1))
    
    # make an image and save it to file
    (def my-module @{:public true})
    (spit "test.jimage" (make-image (curenv)))

Exit and start a new REPL session:

    (defn restore-image [image]
      (loop [[k v] :pairs image]
        (put (curenv) k v)))
    
    (restore-image (load-image (slurp "test.jimage")))

    ((tx 0))

It saved the closure and all relevant image in the `(curenv)` hashmap.

Condensed from my longer response: https://lobste.rs/s/y0euno/why_janet_2023#c_lspe6n

by veqq

6/2/2026 at 11:50:52 AM

[flagged]

by xuzhenpeng

6/2/2026 at 11:25:20 AM

[flagged]

by rohitsriram

6/2/2026 at 2:13:18 PM

[dead]

by nicechianti

6/2/2026 at 10:25:52 AM

    (defn foo [first & rest] ...)

So basically Lisp 2.0.

Although, this here is a good idea:

"pass values from compile-time to run-time"

Would be nice if some kind of "scripting" language be as fast as a compiled language, but without ruining the syntax. Just about 99% of the languages that are shown, have a horrible syntax. Syntax is not everything, but most language designers don't understand that syntax also matters. So tons of horrible languages emerge. Nobody will use those languages, so 99% of them will die off quickly.

by shevy-java

6/2/2026 at 11:09:16 AM

What would be a better syntax according to you? I have found Janet’s syntax very pleasant to work with as opposed to JavaScript, Lua or even Python.

by xigoi

6/2/2026 at 11:00:19 AM

can't there theoretically be a language which transpiles to Janet to get all the benefits without additional paranthesis too?

Not sure if such transpilation would have a perf hit though, I hope somebody responds who knows about it more.

I don't deny that syntax matters itself too but there are some ideas of janet like sandboxing and other features which seem to me to be worth implementing in other languages too.

Personally, I would be really interested in a language like lua/wren which can transpile to Janet too.

by Imustaskforhelp

6/2/2026 at 2:09:54 PM

"... all the benefits without additional parenthesis too?"

I guess you don't like Lisp's syntax. I didn't either until I realized the key insight: when you're writing Lisp, you're basically writing an AST. Which is why it's so easy to manipulate your code. Want a new feature the language doesn't have, such as the pattern-matching they added to C# a few versions back? You can add it yourself; you don't need to wait for a language committee to implement it years after you needed it. That's all that macros are: functions that take AST and return AST, which is then executed.

And once I realized that Lisp's syntax was basically an AST, I no longer saw the parentheses. Now I just see blonde, brunette, redhead... Oops. Sorry. Wrong reference.

by rmunn

6/2/2026 at 11:21:37 AM

I guess you could transpile direct to Janet bytecode, and performance would be in theory the same as native Janet?

by petee

6/2/2026 at 1:08:40 PM

Why, Henry?

by flintenmuschi

6/2/2026 at 10:38:13 AM

why is it called Janet? perhaps to prevent it to be identified with the acronym for Lots of Irritating Single Parenthesis?

by wolfi1

6/2/2026 at 11:06:27 AM

It was named after the sentient computer system in the TV show "The Good Place"

A humourous clip: https://youtu.be/etJ6RmMPGko?si=W98LdG1jDdUCXsHV

by petee

6/2/2026 at 11:17:05 AM

Also mentioned in the GitHub repository:

> Why is it called "Janet"? Janet is named after the almost omniscient and friendly artificial being in The Good Place

https://github.com/janet-lang/janet#why-is-it-called-janet

by embedding-shape

6/2/2026 at 11:04:44 AM

If it was called [Something] Lisp, Lisp enthusiasts would complain that it’s not a lisp because it does not use linked lists as the primary data structure.

by xigoi

6/2/2026 at 10:55:18 AM

I know that Lisp has lots of paranthesis and I don't have enough experience with Lisp at all.

But from the looks of it, Janet has some great ideas like the one that @ramblurr shared here about sandboxing ("Disable feature sets to prevent the interpreter from using certain system resources. Once a feature is disabled, there is no way to re-enable it.")

Lisp from my understanding is incredibly polarizing and many people love it and many people hate it and that's fine, but at a certain point wouldn't it feel repetitive for statement like this and I am unsure of how healthy discussion about programming concepts can be done this way.

There are so many interesting things from lisp-y languages like Janet and Julia is technically lisp-y too and Julia's compilation to GPU is awesome and Nim too which can compile to C/C++/JS!

It's just so many interesting concepts overall in programming that paranthesis don't seem a concern to me as the underlying concept can be translated to something else, like sandboxing feature, transpilation to GPU or multiple targets!

And there are many unique concepts in non-lispy languages like golang (cross-compat, portability with static binaries), elixir (concurrency!) too.

It's just good to see the amount of innovation within programming from all spheres of influence :-D

by Imustaskforhelp

6/2/2026 at 11:22:47 AM

While I do not like the excess of parentheses of LISP and similar languages, their syntax is very consistent and predictable. Moreover, while LISP has an excess of parentheses, it omits a greater number of commas that are required in many other programming languages.

I am much more annoyed by the random syntax inconsistencies of most popular programming languages, which are either caused by original language design mistakes, or, more frequently, by the late addition of some features that were not planned in the original language, so they had to be squeezed in with the help of various ugly workarounds.

While during the last years I have not used much LISP like languages, there have been times when I used them a lot, for several years, in scripting applications, e.g. the LISP variant of old AutoCAD, the Scheme-like scripting language of the Cadence EDA applications, or the scsh Scheme dialect that is usable for replacing UNIX shell scripts.

In all cases, these languages allowed a greater productivity associated with rarer bugs than the more popular scripting languages, like Python, Perl, TCL, bash.

While aesthetically I might prefer the look of a Python program, for solving a practical production problem I would prefer to write scripts in one of the LISP derivatives. Obviously, the productivity in various programming languages depends a lot on individual preferences and previous experiences.

It should be noted by all those who believe that the LISP-derived languages have too many parentheses, that the C programming language and all languages with syntax derived from it, like Java or Rust, have a great excess of parentheses in comparison with the older languages that had better designed syntaxes, e.g. ALGOL 68 or IBM PL/I.

For example, compare

  for (i = 1; i <= 100; i += 5) { ... }

with

  for i from 1 to 100 by 5 do ... od

  if ( ... ) { ... } else { ... }

with

  if ... then ... else ... fi

The first example has 12 syntactic tokens instead of the minimum required, which is 6.

The second example has 8 syntactic tokens instead of the minimum required, which is 4.

If I cannot have a decent programming language with a minimum number of parentheses, I would rather have a programming language where all the places that need parentheses are predictable, like in LISP, instead of having a language like C and its derivatives, which require parentheses in random places, for no good reason at all.

by adrian_b

6/2/2026 at 2:33:33 PM

Now do

    for (i = 1; i <= 128; i *= 2) { … }

with by.

Now do

    if (x <= 0)
        throw ParameterException;

with fewer “syntactic tokens”.

by NetMageSCW