A Road to Lisp: Which Lisp

https://scotto.me/blog/2026-07-17-which-lisp/

by silcoon • 5 days ago

203 168 5 days ago

scotto.me

hnarayanan3• 5 days ago

So many words to say: Scheme.

nobleach5• 5 days ago

Perhaps, but Chicken? Guile? Chez? They're all pretty cool.

tmtvl7• 5 days ago

R5RS, R6RS, or R7RS?

nathan_compton4• 5 days ago

R6RS.

criddell• 5 days ago

Another Lisp of note is AutoLISP.

Elisp::Emacs as AutoLISP::AutoCAD. AutoLISP was my first introduction to Lisp-style language. When I first started using it (1987) for macros in AutoCAD, I really had no idea what Lisp was. It was just a fun and easy way to automate AutoCAD.

hnarayanan3• 5 days ago

I had forgotten about this. The last I saw this was 20+ years ago!

timonoko• 5 days ago

Adding and substracting 3D-objects was the same as in OpensCAD.

Strange they did not make OpenSCAD in AutoLISP-style.

I have to read the manual all the time, because I never learn the weird syntax of OpenSCAD for-statement.

0xb0565e486• 5 days ago

I really wanted to Lisp as a main programming language, and sometimes I still do.

I just find readability such a hurdle regardless of how long I used it. I didn't find that it ever became as natural as the other group of programming languages.

I find a procedural style of programming so much easier to reason about, both when writing and reading.

Either way, I'm really happy I took some time to learn it and use it a little at some point.

dieggsy4• 5 days ago

For me, the most effective way to read Lisp is to essentially forget the parentheses (I shadow them out in matching, low contrast colors) and go almost entirely by indentation. I find this makes it more similar to reading other languages, though granted not exactly the same.

You do have to keep up with the parentheses of course, but editor settings or extensions can make this automatic if not invisible.

groundzeros20153• 5 days ago

(Heresy alert. Inb4 homoinconcity)

I do find that most of my lisp skills carry over to JavaScript quite well while allowing me to write imperative functions more fluently.

Prog blocks are pretty good. I wonder if another DSL could be better.

hnarayanan3• 5 days ago

Maybe because Brendan Eich was tasked with "doing Scheme in the browser" before it pivoted to JavaScript.

whartung2• 5 days ago

I find a procedural style of programming so much easier to reason about, both when writing and reading.

Then do that.

There's nothing stopping you from using pretty much any style of programming that you like. Or mix and match. Or evolve over time.

Loops, lists, arrays, structures. Simple iteration: dotimes, dolist, loop. If those are your bread and butter, then feast! CL will happily do that. That's what I do. I just don't think "functionally" when I do CL code, I'm just not there yet, so its unnatural for me, and not what comes spewing out of my fingers when I write code.

And it's "OK".

You don't have to use the other features of the language, but they're there if you want to dip your toe into it.

With CL, also, I tend to be really wordy on variable and function names. I'm really fond of kabob-case-for-identifers.

Jtsummers7• 5 days ago

Common Lisp code can be very procedural if that's what you want to do. The entire loop macro is basically importing Algol-styled procedural loops into Lisp.

em-bee2• 5 days ago

that's the conclusion i came up with after learning common lisp. it didn't feel much different from what i had learned before.

ux2664782• 5 days ago

Lisp really needs extensive structural editing tools IMO, and you really have to change how you think about reading source text and that can take longer than you might think. The best Lisp experience by far and away is LispWorks. That being said, I never found it to be to my tastes either. Too much focus on making tree-representations of programs the centerpoint, which isn't how my internal grammar works. I'd much prefer less explicit delimitation where it's not actually needed, but that's also incompatible with the goal of sexprs.

iLemming6• 5 days ago

I just find readability such a hurdle

I've had the same complaints when I started. I think, realistically, every programmer who's learning Lisp after getting experience in a bunch of other languages has to deal with that. The mental overhead feels real. Yet, after a while, there's some psychological threshold - Lisp starts feeling more intuitive. At some point, there's just no turning back - nothing ever will feel again more readable than Lisp code. It's just like riding a bike. Once you "get it", there's just no way to "unget it" back.

dieggsy4• 5 days ago

CL also has pretty much arbitrarily extensible syntax:

- https://sr.ht/~dieggsy/whisper/

- https://dieggsy.com/json-literals.html

And could also be used to build languages, supporting more modern programming paradigms (though yes, I believe Racket does make this easier):

- https://coalton-lang.github.io/

I also might have written the Common Lisp example using reduce as well, which is in the standard library, but that's preference. Nice to have the option though:

  (defun calculate (instructions)
    (reduce
     (lambda (result op-value)
       (destructuring-bind (operation value) op-value
         (case operation
           (:add (+ result value))
           (:subtract (- result value))
           (:multiply (* result value)))))
     instructions
     :initial-value 0))

  (calculate '((:add 5) (:multiply 3) (:subtract 4))) ;; => 11

BoingBoomTschak7• 5 days ago

I'd have used

  (funcall (ecase operation (:add '+) (:subtract '-) (:multiply '*)) result value)

instead, looks funkier =)

dieggsy4• 5 days ago

Oh yeah, way more fun :) I just kinda saw CL in the Clojure and was trying to make it look like that.

kazinator5• 4 days ago

Did you know CL allows keywords to be function names?

  [1]> (setf (symbol-function :add) (function +))
  #<SYSTEM-FUNCTION +>
  [2]> (setf (symbol-function :subtract) (function -))
  #<SYSTEM-FUNCTION ->
  [3]> (setf (symbol-function :multiply) (function *))
  #<SYSTEM-FUNCTION *>
  [4]> (setf (symbol-function :divide) (function /))
  #<SYSTEM-FUNCTION />
  [5]> (reduce (lambda (x y) (funcall (car y) x (cadr y))) '((:add 5) (:multiply 3) (:subtract 4)) :initial-value 0)
  11

This is actually a small benefit of the two namespaces. Keywords can't be variables because they evaluate to themselves, but that is not relevant to the operator position that does not resolve variables.

pooyamo• 5 days ago

The LOOP solution could be written using DOLIST or DO forms too (likewise built-in):

  (defun calculate (instructions)
    (let ((result 0))
      (dolist (e instructions result)
        (destructuring-bind (operator operand) e
          (setf result
                (case operator
                  (add      (+ result operand))
                  (multiply (* result operand))
                  (subtract (- result operand))))))))
  
  (defun calculate (instructions)
    (do ((result 0))
        ((null instructions) result)
      (destructuring-bind (operator operand) (pop instructions)
        (setf result
              (case operator
                (add      (+ result operand))
                (multiply (* result operand))
                (subtract (- result operand)))))))

BoingBoomTschak7• 5 days ago

(Disclaimer: CL weenie) A decent and balanced writeup IMO. But it should really have contained the following:

Warning about the issues that come with ANSI CL's frozen spec (threads/sockets/unicode/extensible sequences/gray streams/etc... as extensions with a varying amount of support with compatibility layers often available to write portable-ish code, "bolted-on" CLOS never fully integrated) and its various rust spots, not just the good points.

Mention that CL has provisions for gradual typing (with limits) which are exploited by SBCL.

Scheme, obviously, along with the same warning as CL about pain of writing portable code that interacts with the OS (does it have compatibility layers like CL?) amplified by the R6RS vs unfinished R7RS-large mess.

A few words about the build system/third-party packaging situation and alternative implementations.

groundzeros20153• 5 days ago

For me the complete spec is the killer feature. You can learn Common Lisp in 1990 and write it the same now. As long as we can keep the compilers alive it will be forever.

It’s funny to me that it was critiqued for being “bloated” when now it looks like a focused minimal library.

dismalaf3• 5 days ago

Common Lisp wasn't standardised until 1994.

Also, SBCL has some nice features specific to them, I'm sure it's the same for other implementations. So while there's a lot that's common between them all I find myself using a lot of platform specific functions.

Jtsummers7• 5 days ago

Yes, but it existed before then (from 1984 on), and a large amount of code written for CL pre-standardization still runs without alteration or with minimal updates.

pfdietz2• 5 days ago

It's small enough a single person could write a test suite for the whole standard.

ChrisArchitect• 5 days ago

A road to Lisp: Why Lisp

https://news.ycombinator.com/item?id=48845209

ynniv2• 5 days ago

I have a work-in-progress called Modus. 100% written by Claude, so take that however you will. The current release boots on a Raspberry Pi Zero 2 W. The next release (unreleased in the pipe for ~ months) is standard Common Lisp on bare aarch64 (pi) and x64 (qemu for now), with linux aarch64 and x64 command line interfaces à la sbcl.

https://github.com/modus-lisp/modus

Since you can't use an OS by itself, I've rounded out the Common Lisp environment with portable ssh client and server, web browser, and a bitcoin node. Framebuffer with VNC in the pipe

whartung2• 5 days ago

That's pretty neat!

God help me if I fell down a hole like that.

I must say, however, that e.g. code like (compile-compound) is something only an AI can love!

ynniv2• 5 days ago

i've spent decades reading and writing code. i just want something that works

BoingBoomTschak7• 5 days ago

There's https://scheme.fail/ for bare metal Lisping too.

nobleach5• 5 days ago

Since a few folks here recommended Common Lisp to me as the language that would "tick all my boxes", I've been doing a deep dive. Right now, I'm working through SICP again with DrRacket. The first time I worked through it with MIT Scheme MANY years ago. It's shocking how much I've forgotten.

What I like about this article is that it walks through the different "camps" of Lisp. Scheme is so intriguing to me because of how small it can actually be. I can build nearly any paradigm I want to exist. The problem is, if I were to actually go find a job where they were using a Lisp, (I hear those actually exist) they wouldn't want to use my "Result monad + match statement - railway pattern" that I've used from OCaml and Rust. So learning something that is truly "common" can make more sense.

As far as learning though, Scheme feels "just right". I've imposed a "no AI until I've found a working solution" rule that keeps my mind engaged. Couple that with a willingness to say, "I don't know that right now... I'll think about it throughout the day and maybe by this evening I'll have an answer".

AyanamiKaine• 5 days ago

I can also recommend clojure. For me it has the best parts of common lisp and the best of the java ecosystem. But its also quite different from common lisp and scheme. Different enough to find some unique ideas.

Writing scripts using [0] Babashka is also really nice.

[0] https://babashka.org/

nobleach5• 5 days ago

I particpated in a Clojure reading group for "Getting Clojure" back around 2017. Having the entire JVM ecosystem available, is absolutely a great benefit. I even fooled around with ClojureScript a bit. David Nolen is great at making the case for both.

waffletower• 5 days ago

Babashka is really nice indeed. Am hopeful for the C++ hosted Clojure dialect, Jank (https://jank-lang.org)

snorremd• 5 days ago

As a former Clojure dev (now just using Clojure in my spare time) I love Babashka. Michiel Borkent really nailed it with sci (Small Clojure Interpreter) and Babashka. Running a custom Clojure interpreter in a GraalVM compiled Clojure app is quite clever.

Now there are of course limitations to what you can do in terms of not supporting Java reflection or the full Clojure compiler. But I've made some nifty small scripts and convenience helpers with it. And the dev experience of making these scripts is so much nicer than trying to write bash scripts. The Clojure edn syntax is super simple, and the REPL connected editor let me rapidly test parts of the code just like with full Clojure apps.

I don't have experience with other lisps, but I can vouch for Clojure being very nice. The community was welcoming and friendly to newcomers when I started learning, I hope it still is. One thing I love about the Clojure ecosystem and community is the effort taken to never break libraries. I've looked at libraries I used some ten years ago, and the API is still compatible with code I wrote back then. There is very little churn. Maybe this is because the language is largely untyped and editors only partially check "types". Having breakages in libraries you consume once every couple of months would get really tiring in Clojure land. I'd imagine the same problems would present themselves in Common Lisp and others.

zackmorris• 5 days ago

For what it's worth, Scheme was the first programming class that I took at UIUC around 1995, as I recall.

I had used C++ for several years to make shareware games, so I took a test to challenge some programming courses. I vaguely recall doing well, but my advisor encouraged me to take them anyway. I'm glad that I did, because I had little understanding of theory.

Funny story: the instructor never mentioned that we could use more than one line of code. So every single piece of homework that I handed in, and every test, was one giant line of nested logic. Which worked better than one might expect, and completely changed how I wrote code from that point forward. That's how I made the connection a decade later that functional programming is akin to a spreadsheet, as are higher-order method chains and immutable variables.

I think of Clojure as being a layer above Lisp, sort of like how Swift might be considered a layer above Objective-C/Smalltalk. However, bare Lisp has problems around not quite giving enough out of the box. It's minimalist enough that developers end up reinventing the wheel for things that should probably be provided by a layer/library similar to Scheme or Clojure.

To digress, I feel that mutable variables and even monads are a code smell in functional programming since they can cause impurity. They're more of a crutch to ease conversion of code from imperative languages. However, monads can be useful to simulate every path through a program, sort of like superposition in quantum mechanics and SAT solvers. So they aren't necessarily bad, just taught incorrectly, probably because they're so hard to grok.

I'd vote to settle on a series of layers like Common Lisp -> Scheme/Racket -> Clojure/Elisp, with the final layer providing the intersection of features available from the most widely-used Lisp variants. Note that this is specifically to form a bridge from imperative languages, so research work might need additional DSL features brought forth from the Racket layer.

Edit: I forgot to mention that Scheme is a good fit for genetic algorithms, see books by John Koza (no affiliation). My feeling is that we haven't seen anything yet regarding what problems AI can solve, since it's having to do it the "bare hands" way with LLMs and pattern matching.

sph2• 5 days ago

I dislike Common Lisp, and I fear it keeps ruining the reputation of Lisp itself with its archaic and obtuse systems designed by a committee of dinosaurs. This opinion will attract the ire of many a greybeard. I stand by it.

If you want a Scheme with batteries included, I recommend GNU Guile. Also worth your time are Racket, Clojure, Janet.

hackermailman• 5 days ago

In Sussman's book 'Software Design For Flexibility' he uses Match? in the pattern matching chapter to run on graphs. I think OCW archived his MIT course for the book too

nobleach5• 5 days ago

Yeah, guile has a library that looks close to what I want. The worry is that railway programming is an entire shift in error handling. Since it's not the standard that I've seen in the Lisp/Scheme world, I'd be forcing a paradigm that no one wants.

Diogenesian• 5 days ago

The Scheme Programming Language by R. Kent Dybvig is very much worth reading after you finish SICP. Truly the same caliber as K&R's C Programming Language, and more up-to-date (R6RS). The earlier exercises aren't too tricky (except call/cc headaches), but the final chapter has some good meaty Scheme projects that will teach you a ton.

It's free online: https://scheme.com/tspl4/

lkuty• 2 days ago

I also have started doing SICP recently with Racket and `#lang sicp`. Sometimes I skip some exercises and will come back to them at a later time. It allows me to choose when to advance reading the text or make the exercises. So far in section 3.1.3. Discovered MIT Scheme in 1996 at university, got plenty of scheme books for years including SICP, and each year telling myself that I should do this classic. I am reading the pdf version of https://github.com/sarabander/sicp because it is more practical than using the paper book. Recently I bought the instructor's version of the book.

wollowollo• 5 days ago

I wonder if Hylang is still alive.

bbkane• 5 days ago

There's also Rhombus now: https://docs.racket-lang.org/rhombus-quick/index.html

pratikdeoghare• 5 days ago

Shut up and learn Common Lisp using Practical Common Lisp.

This would be my advice. Why? My own road was haphazard. Other books broaden your mind and teach you really cool tricks. This book gets you using lisp like you would say golang. But it still teaches you the lisp things and broadens your mind. Time spent choosing will be better spent reading this book. After that PAIP, On Lisp, SICP etc.

mktemp-d• 5 days ago

Piggy backing to apply more recommendations too.

An Introduction to Programming in EMacs Lisp is also good for the first few chapters even if you don’t use emacs because you are given fundamental concepts of lisp that can be applied to the understanding of other dialects. It’s also free.

Learn you a Haskell (despite Haskell being not a flavor of list, they share similar DNA ) is great at understanding functional programming with lisp like languages.

em-bee2• 5 days ago

that's the book i learned with. it got me far enough that i was able to write two applications that i ended up using for several years.

davidw• 5 days ago

When people have a lot of choices, that can create problems, because it's often the people with the least information trying to make that choice.

For instance "I'm new to Lisp, I want to try one..." is a person without a lot of background and information to make that choice. And they probably realize it and it makes them nervous about making that choice.

See: https://en.wikipedia.org/wiki/The_Paradox_of_Choice

goatking3• 5 days ago

I just wish a good IDE existed so I don't have to use Emacs. That's what made me drop lisp in the past.

I would be happy with (neo)Vim setup as well, but that was way behind Emacs and broken when I tried.

jacobobryant• 5 days ago

as of now neovim works great with clojure, not sure about other lisps. vs code also.

goatking3• 5 days ago

I am/was mainly interested in Common Lisp. I might give Vim another try, that would be the best if it worked. I really don't like vscode

ux2664782• 5 days ago

LispWorks - https://www.lispworks.com/

goatking3• 5 days ago

Thanks.

However, price for hobby user license at 750 USD is laughable.

aptenoforst• 5 days ago

You have two newish options nowadays

https://coalton-lang.github.io/20260424-mine/ and https://lem-project.github.io/

iLemming6• 4 days ago

so I don't have to use Emacs

While there are many reasons to perhaps stay away from Emacs, realistically, for any serious Lisper, there's just no other alternative - sadly or otherwise.

I think, collectively, as the industry force, we software developers having now to pay imperceptible price for disregarding the pragmaticism we had/have in systems like Lisp and Smalltalk. We standardized on dead artifacts: text files compiled into opaque binaries, restarted on every change. We rebuilt weaker versions of what those systems had, piecemeal, decades later, and call them innovations.

You don't notice the cost because it's spread out. Nobody ever gets handed the bill. Instead it shows up as little bits of friction across millions of hours of work: slow feedback, extra steps, tools that treat a running program like you can't touch it. We took the accidental limits of file-based, restart-everything development and assumed that's just how programming works. And quietly, all together, we paid a huge price for giving up the live, flexible systems we already had.

Emacs is one of the last mainstream artifacts that still embodies that old ethos. For serious Lisp work the alternatives are pale because they still treat code as text to be sent elsewhere, rather than a live system you live inside. This lock-in isn't some kind of nostalgia, it's just nothing else preserves that property.

I wish there were more Emacs-like systems, instead of dozens of tools that all trying to solve same or similar problems - how many different tools are there for Python alone just to unmess its cascaded dependency woes? Or look at the whole containerization tower - Docker, Compose, k8s, Helm, Nix - all because we've "forgotten" how to reliably reconstruct a running program's state.

TLDR: Don't ignore Lisp - it's not archaic, it's not "theoretical", it's practical, it works and it works well. And once you get some serious footing with Lisp, you'll sooner or later come to appreciate Emacs, and then will be forever frustrated that we don't build Emacs-like systems anymore. You'll hate Emacs and whenever you do, you'd be reminded that there's no better alternative in existence. Sadly or otherwise.

kscarlet2• 4 days ago

VSCode: https://github.com/kchanqvq/olive

iFire2• 5 days ago

Since this is the largest gathering of LISP users I have seen, I have a question.

Why prefer lisp-1 over lisp-2 or vice-versa?

dismalaf3• 5 days ago

IMO if we look at Lisps today the question looks more like: SBCL, Chez Scheme, Racket or Clojure.

Common Lisp and Racket are Lisp-2s but honestly, the namespace thing seems like a minor difference compared to all the other features that differentiate them.

gus_massa• 5 days ago

[Racket is a lisp-1.]

jwr• 5 days ago

As someone who has used both kinds over many, many years: it really doesn't matter.

guenthert2• 5 days ago

How about the distinction between the boolean value false, the empty list and whether an empty list ought to be true or false? ]:->

Jtsummers7• 5 days ago

Ignoring all the other distinctions between lisps, the main difference between lisp-1 and lisp-2 (or lisp-n) is going to be how clean your code looks when you lean into the FP style. In a lisp-2 you'll need to do something like this:

  (defun apply-twice (f x)
    (funcall f (funcall f x)))

  (apply-twice #'1+ 2)

Versus this with a lisp-1:

  (define (apply-twice f x)
    (f (f x))

  (apply-twice 1+ 2) ;; assuming 1+ is defined

But there are so many other differences between the lisps in the two categories that this probably won't be the deciding factor for most people.

wk_end• 5 days ago

The argument is: if you don’t have hygienic macros, a Lisp-2 is going to be less brittle than a Lisp-1.

The classic example is, imagine you have a function with a local variable called “list”, common enough. Now imagine you invoke a macro inside that function which generates a call to the built-in “list” function - also common enough. In a Lisp-1 without hygiene that breaks - your local definition shadowed the built-in; in a Lisp-2 or hygienic Lisp-1 you’re in the clear.

nathan_compton4• 5 days ago

People should never use non-hygienic macro systems anyway, but even if they are using a non-hygienic macro, they should always use proper hygiene. Its kind of dumb to make the whole system weirder just to avoid issues which should never happen in the first place, in my opinion.

Jtsummers7• 5 days ago

@nathan_compton, your sibling comment to what I'm writing now is [dead] (not [flagged]) but you're not shadowbanned, newer and older comments are still alive. I vouched for it but it's still [dead], you may want to reach out to the mods.

nathan_compton4• 5 days ago

I am a strong proponent of Lisp 1, primarily because the distinction between functions and other types of values is artificial. Functions have first class semantics in Lisp 1 and Lisp 2, but Lisp 2 makes you denote them differently but in an inconsistent manner.

Lisp 2 advocates typically make a few arguments. One is that having a separate namespace for functions makes it clearer when you are using a function vs another value. The second is that the evaluator has less work to do when examining the head of a list - it needs only look in the function environment, not the full environment.

On the first subject I must disagree - you can bind a function to a regular variable and then use that variable everywhere (except in the car of a list representing a function call), so for most positions in a set of expressions you don't really get information about whether the object being denoted is a function or not.

I suppose the second point is somewhat valid, though I suspect if you benchmarked interpreters and compilers it would barely matter. As a person who favors functional programming with a lot of combinators, I find Lisp 2 introduces a lot of pointless noise in the syntax for no reason. And I fundamentally just don't see functions as significantly different sorts of values, so I find the syntactic distinction bizarre.

sph2• 5 days ago

Having a separate namespace for functions is silly in that it only saves you from a small set of variable shadowing problems. It’s a hack, not a serious solution.

zem4• 5 days ago

personal taste, for the most part. I like the thought of a single namespace, it fits my intuition from pretty much every other language out there, and I like how the code looks when I can pass functions around as though their names are regular variable bindings to an underlying function object.

coryrc• 5 days ago

I hate having to come up with different variable names than `list` so I don't shadow the function `list`. Repeat that for a lot of common words: count, first, length, map, max, min, search, string; that you would then actually consider calling said function after declaring a value. Happens to "list" the most, but definitely the others on rarer occasions.

tmtvl7• 5 days ago

The usual argument I've seen in favour of Lisp-2 (I personally don't care as much about the function namespace as I do about the type namespace, which I find much more important) is that you can name an argument a conflicting name with a function without the conflict interfering with the code you would write:

  (defun merge-sort (list before?)
    (declare (type List list)
             (type Function before?))
    (flet ((merge-2 (a b)
             (declare (type List a b)
             (merge 'List a b before?)))
      (unless (null list)
        (reduce #'merge-2 list :key #'list))))

  (merge-sort '(1 9 8 2 3 4 7 6 5)
              #'<)

Instead of having to name lists 'lst' or something. Which is pretty much personal preference anyway.

xigoi2• 5 days ago

Isn’t this only a problem if the language is case-insensitive?

kazinator5• 5 days ago

Lisp-1 has the wart that it models special operators as bindings in a variable name space. So a form like (print let) actually resolves let to a binding to a special operator, and then has to be somehow pronounced as nonsense. And you can block let from working by binding that as a variable name. Allowing variables to shadow the basic operators of the language is quirky.

Would you want to use a weird POSIX shell in which "for x in *.jpg; ..." stopped working because you assigned "for=42"?

Yet Lisp-1 has a notational advantage for programs that work with functional values; programs that indirect upon functions are more succinct, free of "shim" operators for lifting values out of the function binding space, or requesting application of a function value.

In the TXR Lisp dialect, I worked out a way to have the notational convenience, without bringing in the Lisp-1 issue.

1. The substrate, including macro-expansion logic, is thoroughly Lisp-2.

2. When a compound form is written in square brackets, it indicates that immediate elements (those constituents that are symbols) are to be looked up in a single namespace that is a merger of the function and variable namespaces according to precisely documented rules. This is not recursively applied to the form; its arguments that are compound forms are not treated this way unless they use square brackets.

3. Macros are not affected. In a form [a b c ...], the element a is neither recognized as a special operator or as an operator macro. If it is a symbol, it is either a variable, or a symbol macro.

4. [ ... ] is a surface syntax with a straightforward representation: the (dwim ...) operator. The above semantics is thoroughly baked into the macro expander and correctly treated at all necessary levels of the language: the handling of lexical scopes at expansion time and compilation/evaluation.

This system leaves mainly just one small infelicity. The merged 1+2 namespace is not available in certain contexts when it would be handy. Like say we are writing a function that takes a functional argument, that we would like to default:

   (defun my-sort (sequence : (test-fn equal)) ...)   ;; nope!

There is no variable equal. We cannot do this:

   (defun my-sort (sequence : [test-fn equal]) ...)   ;; nope!

because the (test-fn equal) syntax is not a form to be evaluated; it is just notation within the parameter list which has not been equipped with support for the alternative brackets/dwim structure. The way to do this is:

   (defun my-sort (sequence : (test-fn (fun equal))) ...)

fun* is like Common Lisp's function* operator. It's one of the few instances you ever have to use it, the others also being situations like values in binding constructs such as let. It is not worth complicating things to provide a way to take the fun out these situations.

belmarca• 5 days ago

Gambit Scheme (https://github.com/gambit/gambit) is a highly performant Scheme implementation (https://ecraven.github.io/r7rs-benchmarks/). Gerbil (https://cons.io) is built on top of it.

Both highly recommended.

kscarlet2• 5 days ago

PSA: VSCode users deserve to use the OLIVE plugin (https://github.com/kchanqvq/olive).

adamddev13• 5 days ago

How to Design Programs with Racket was life changing.

https://htdp.org

That helped me to think about recursion, functional programming, and type driven development. After going through HTDP I was able to breeze through complex problems that were unsolvable before.

fuzztester2• 4 days ago

After going through HTDP I was able to breeze through complex problems that were unsolvable before.

examples?

adamddev13• 4 days ago

Natural language phrase generation in a very complex foreign language that follows recursive syntax trees. And making a GUI to handle and edit these syntax trees visually.

QuadmasterXLII• 5 days ago

The funny thing about Lisp is that writing a Lisp interpreter is significantly fewer keystrokes than correctly installing Common Lisp and its tooling. The ratio of lisps to lisp programmers may actually be above 1.

pfdietz2• 5 days ago

Lisp interpreters are easy to write; a performant and standard compliant Common Lisp system is considerably harder to write.

zem4• 5 days ago

this is definitely true for forth (:

lioeters2• 5 days ago

Literally a comment I wrote then decided not to post.

The best LISP is the one you create yourself. You learn so much about programming by implementing your own language, and LISP is brilliant for this purpose thanks to its simple syntax and homoiconicity (code is data, data is code). It's also a great way to learn a new existing language, like Rust or Go, by writing a LISP interpreter with it.

gnabgib• 5 days ago

Thank you for not posting it

tmtvl7• 5 days ago

Depends on how much tooling you want to install and where you want to be on the spectrum from:

  (loop :do (print (eval (read))))

to implementing all of Common Lisp in RISC-V assembly:

  pacman -Syu sbcl emacs
  M-x package-install slime RET

isn't a lot of keystrokes.

phplovesong• 5 days ago

There is also MLs that have the same idea, but with less implementation, as a lisp is something you hack in a weekend. An working ML not, as it takes way more effort.

Lisps have many fantastic ideas, but are really hard to read. Lisp code is what we had before perl guys went "hold my beer".

I know its just syntax, and it usually does not matter, untill it does. I did some clojure a long time ago, and before that some CL, and god, i cant understand my own old code. Contrast that to some language that has syntax i can read it still, years later. Go being the prime example of write once, read a decade later.

nathan_compton4• 5 days ago

I find Lisp much easier to read than most other languages. It is highly explicit syntax with very little ambiguity, especially if you have a little discipline about macros.

spdegabrielle3• 5 days ago

I like the Python-like indentation syntax of Rhombus. It has the extensibility of a modern lisp https://rhombus-lang.org/

prakashrj• 5 days ago

https://www.youtube.com/watch?v=LXhsutNKhec&feature=youtu.be

Once you get hang of it, it easy. Following is video of my son who learnt Scheme as first programming language.

spdegabrielle3• 5 days ago

If you want the extensibility of Lisp with a readable syntax Rhombus is worth a go https://rhombus-lang.org/

PaulHoule4• 5 days ago

I'm going to take the opposite position that there is much less special about Lisp than people think. Like I have met so many programmers that travel around like itinerant martial artists looking for true functional programming and they never find it.

To be specific, you can work all of the examples in Graham's On Lisp in Python except for one of the last chapters where he implements continuations that really need macros -- but this is basically the async/await facility that Python already has. The other examples use macros for performance but work fine with just plain functional programming.

React with hooks is an example of that kind of system at work -- the JSX transformation is a very simple shim you can put in front of the JS compiler and the hooks themselves are the kind of trick that On Lisp teaches you how to do.

On Lisp doesn't use the kind of tree-walking macros that really are unique to Lisp. And... the techniques in the Dragon Book for writing compilers are the real magic. If looking to Lisp as an old shiny keeps you from learning how to write compilers, it is holding you back.

I think the homoiconic thing leads people astray. There's a real tension that, for performance reasons, mainstream compilers aren't extensible, for instance you might want to write a

  unless(X) {...} => if(!X) {...}

control structure in a new language and for something in Java that is really a production rule in the grammar, maybe a class to represent the unless block, and a rewriting rule that gets applied to the AST. If the compiler was designed to be easily extensible that would be less code than the POM file for the project. But it's not so it isn't.

Many things hold us back.

The industry has been so traumzatized by slow compiles that trading speed for extensibility doesn't sell to the people who create languages. Also once you have the sophistication to make things like parser generators you know how to get things done with the terribly unergonomic parser generators we have and don't have a lot of empathy for all the programmers out there who might be using parser generators if any of them were built as if usability matters.

pjmlp5• 5 days ago

Except that CPython still misses on (compile .....) part, indeed holding the industry back.

PaulHoule4• 5 days ago

it compiles to bytecode but the bytecode engine is not that fast.

i had a phase when I was using PyPi a lot for branchy "old AI" kinds of workloads and felt it was an easy win but since then it has been either numpy or PIL or pytorch doing the heavy lifting or scripty stuff like uploading files to S3 where performance doesn't matter a lot.

I will grant that Common Lisp can be compiled to run amazingly quickly!

guenthert2• 5 days ago

Not sure about that. I rather think it's the very dynamic nature of Python (e.g. at run time one can add members to classes) which limits performance gains achievable by compilation. Iirc PyPy got to some five fold performance gain against CPython.

Common Lisp, as an example, makes some deliberate flexibility (and elegance) vs. performance trade-offs. I'd think to speed Python up more than PyPy could, one would have to sacrifice some of its features (some of those might not be all that popular or even desirable).

Nah, Python has its place. If its performance isn't adequate for the problem at hand, rewrite the bottlenecks in C++ and be done. LLMs should make that easy, no?

iLemming6• 5 days ago

There's nothing "special" about Lisp and Lisp dialects, yes. Similar features can be or already have been implemented in other languages. Yet, after touching, using and experiencing working with a bunch of different stacks, I cannot simply ignore the enormous pragmatic level of Lisps.

Working with Clojure is an absolute delight. It strips down all the dogma and let's you deal with the "business logic" as if you're cooking steak using no BS ingredients - meat is meat, herbs are real, stove is hot.

Why would I ever choose bash for writing anything slightly more complex than simple redirection, when I can do things in way better fashion with babashka. Why would I wrestle a YAML CI pipeline that only fails on push, when I can drive the whole thing from a babashka task file, run each step locally in the REPL, and actually debug it?

Why would I ever deal with Lua, if I can't even format it for "readability" - no matter how I do it, it just looks darn ugly, and luafmt often makes it worse. Why, if I can just slash down dozen lines of Lua boilerplate compressing it into a three-liner Fennel macro? With Fennel, I can interactively poke through elements of my WM through Hammerspoon on Mac, and that's just bananas.

Why would I ever deal with JSON, when EDN is almost twice as compact and far more readable - I can align things and treat data as a literal table. Besides, I can group, sort, filter, slice, dice, salt & pepper that data easily, without ever leaving my trusted editor.

Why would I choose to build a web-scraper in Python, when I can use nbb driving Playwright and go through selectors interactively, directly from my editor, as if it is a devtools console. And I don't even have to restart anything, deal with state changes, etc.

How can I abandon Emacs where I can just open a scratch buffer, type some Elisp and change the behavior of my editor, my WM, my OS and even things on remote computers. No other text editing environment works the way Emacs does - nothing even comes close. It feels like playing a video game, where my controller in my editor.

Why would I write Flutter UIs in Dart, fighting the widget-tree ceremony and endless build() boilerplate, when ClojureDart lets me express the same tree as plain data and hot-reload it interactively? The layout is just nested maps and vectors.

Why would I reach for C when I need to embed a small, fast scripting layer. Text parsing alone would be a regex nightmare elsewhere.

Why would I bolt a templating engine onto HTML strings, when Hiccup makes markup just vectors - so my views compose, filter, and generate like any other data, no special templating DSL to learn

And with all sorts of different runtimes and dissimilar Lisp dialects, it still feels as if you're working with the same language. The mental overhead when switching is so negligible. While switching between just JS and TS - which are supposed to be of the "same family" - feels quite annoying. Despite the fact that I've put years into those - far longer than any Lisp I've ever used.

Sure, nothing special about Lisp at all. Except that practicing Lisp can actually make you a polyglot. You'd realize that it isn't syntax that makes a programming language, but runtime and semantics do. After years of dealing with different PLs, I lost a preference for one specific language - I'd choose the runtime best suitable for the task, and then see if I can bolt Lisp on top of it. And these days, it feels like there isn't a platform left where you can't meaningfully do things via Lisp.

PaulHoule4• 5 days ago

I've got really mixed feelings about Clojure. Like when I read Graham's book I went through a phase of "he wouldn't be fighting with nconc if he was using Clojure!" I find some algorithms to be easy and fun to write using persistent data structures and others maddening though if I did it more I'd get better at it. zippers are weirdly unergonomic because of some little bad choices. I badly wanted to do a project with the Clara rules engine but never got the chance.

As for GNU emacs I got over it. Like I was introduced to it in 1989, it was the cool new editor for the Unix world, one of my friends loved scripting with it. However I experienced it getting really janky about 20 years before other software got janky and I don't know why. Some of it might have been rot in things it depends on, like it used to be curses apps actually worked right but now they suffer data corruption from the telnet/ssh connection and always seem to have an off-by-one on the screen size. X Windows got glitchier. I guess emacs was ahead of its time, now people write janky apps with Electron -- like I have to type R E A L L Y : S L O W L Y when I use Slack at work. Photoshop is like that too, computers are 100x's of times faster so Photoshop should boot up faster than Momo Chiyoda can transform but no, it doesn't.

I switched to vim around 2003 as my emergency Unix editor because I could log into a busted system and start working and not have to rely on the package system (often the thing that was busted) to install emacs or build it from scratch. Helps that it doesn't use continuation characters so cut and past just works, there are lots of little things that make vim live more comfortably side by side with modern GUI life than emacs does.

kazinator5• 5 days ago

1. Languages that have all the Lisp features are in the Lisp family. Thus languages that are not in the Lisp familly are ones that don't have all the Lisp features. Once a langauge disappears behind the event horizon of the Lisp family, outsiders no longer distinguish it from any other member of the Lisp family; it's just Lisp.

2. Having some features of Lisp is not the same thing as having those features in that form and integrated in that way.

It's not just the roster of features, but how they blend!

If two features have to speak with each other through some interpretation layer, that spoils everything.

BoingBoomTschak7• 5 days ago

You're really misrepresenting Lisp macros here, being able to rewrite syntax is only one (admittedly important) facet of these.

The real thing with CL is that the entire language is available during parsing and macro expansion and that users can hook into these steps to influence them. No artificial limitations like you get in C++'s consteval, you can do everything and anything without having to use a crappy DSL to do it.

Also, I've never found SBCL slow to compile. Have you?

PaulHoule4• 5 days ago

(1) SBCL is fine in terms of speed so far as I am concerned. But wherever you have software engineering in the large, especially involving C++, you have 40 minute builds and a split between smart people who think that's a problem and smart people who don't.

(2) The trouble with those balls-to-the-walls macros is that systems that use them tend to be "write only", like some guy writes 4000 lines of Lisp that do the work of 80,000 lines of C++ and then he moves on and there is never a version 2.0 but the system gets rewritten in C++, supposedly for performance, but really because they couldn't find anybody who could maintain it. It is really pleasing to see how little code is in Lisp systems from the golden age of AI but... when Yahoo! bought Graham's startup they kept the customers but threw away the code.

You are more likely to be sustainable if you get two people to write 12,000 lines in something like typescript or ML that uses Dragon Book technology to the same end.

patterns• 5 days ago

While I (think) understand the sentiment (ergonomics and practicality), it is still worth studying Lisp for a number of reasons. In particular, I would recommend to everyone to study Lisp 1.5 [1] to appreciate how an entire universe of programming languages can be bootstrapped with just a few primitives and equations.

It is true that, today, we have a vast array of impressive tools at our disposal, from parser combinators and generators, code generators to entire language workbenches with projectional editing capabilities. However, if one were to design a language for any reason, having a deep understanding of the expressiveness of computational models such as the lambda calculus would certainly be an "advantage" (especially for those who end up having to use the language): A Lisp/Scheme is as close to interactive lambda calculus as it gets. From there on, one can learn about implementing different evaluation strategies, scoping rules and continuations (William Byrd's "The Most Beautiful Program Ever Written" [2] also to mind).

Now, I am not sure whether homoiconicity tends to lead people astray. It is true that is it not strictly necessary to make a language extensible (e.g., Smalltalk has no macros and is very extensible due to its powerful meta-object protocol and an elegant syntax for closures), but it's still worth studying the concept. For example, writing a metaintpreter in Prolog [3] is surprisingly easy because of its homoiconicity.

[1] https://softwarepreservation.computerhistory.org/LISP/book/L...

[2] https://www.youtube.com/watch?v=OyfBQmvr2Hc

[3] https://www.metalevel.at/acomip/

loose-cannon2• 5 days ago

I thought Scheme was just an educational tool - a minimal language that allows the student to explore language construction & design relatively quickly. I'm not sure I understand your comment about homoiconicity leading people astray. Isn't that the characteristic feature of lisp? Doesn't that dramatically simplify generating code (in principle)?

Jtsummers7• 5 days ago

I thought Scheme was just an educational tool

That's one use. It's also used in commercial and open source systems. Guile, for instance, has been used as an extension language (like lua and others) in many projects.

jrapdx3• 5 days ago

I find it interesting that a number of PLs were initially developed as educational or research tools but later expanded for general use. Some examples are Pascal, Scheme, Prolog. AFAIK many development languages are used in education so the distinction is rather fuzzy.

Several Scheme implementations, e.g., Chicken, Chez, Gambit, are capable of producing almost any type of program. I'm most familiar with Chicken Scheme. Comes with a large "standard" library plus a broad range of available extensions. Its easy to use FFI adds to productivity.

My experience anyway. Of course, mileage varies widely among users of any language.

kazinator5• 5 days ago

the techniques in the Dragon Book for writing compilers are the real magic.

Can confirm; got a few hints from the 1988 edition when working on the TXR Lisp compiler.

Oh, and also when implementing regexes, not to forget!

However, the Lisp compiler has its own magics that are not exactly covered in the Dragon Book. Some really nice way of doing things.

hajile• 4 days ago

I might buy this if those languages were actually faster. Instead, implementations of scheme with no commercial backers run circles around scripting languages with huge budgets.

Common Lisp can match and exceed languages like Java without the backing of a megacorp.

Carp Lisp is basically identical to C in performance and old PS games were shipped in a proprietary dialect (GOAL) and had very good performance.

Lisp has proven itself capable great performance at every abstraction level.

arikrahman2• 5 days ago

All roads lead to Lisp

phtrivier3• 5 days ago

From my experience, to be happy I would need the perf of sbcl, the syntax, litterals and data structure of clojure, the begginer-friendlyness of drracket, the type system of ocaml, and the dev experience of rust.

Does that exist somewhere ? I hope jank gets there. Or maybe roc will.

At this point, given the progress and expectations of using LLM, writing code is going to be purely a hobby concern, like carving wood furniture became a hobby once you have Ikea.

So we might as well use fun tools :)

totalperspectiv• 5 days ago

Carp has been slowly inching forward and ticking those boxes

SomeHacker44• 5 days ago

Please say more about the "dev experience of rust." As a long time Lisper and not much of a Ruster, I found the dev experience very painful. Granted, I expect had I continued using Rust that would have abated in tjme. I also disliked Clojure at first until I became comfortable with it and productive, before coming to like and appreciate it.

phtrivier3• 5 days ago

- a single, canonical, sanctified toolchain for "all the things that are require but don't matter"

What's the "cargo xxx" of lisp ? It depends. Maybe it's "quicklisp something". Maybe it's "ASDF something". Maybe it's a mixture of three different things and you ask a dumb question on SO that should be in the first page of the manual, and you get 10k views : https://emacs.stackexchange.com/questions/83200/given-a-bran...

I know, you enjoy the power of having options, configuring everything, and shaving your yaks to the bone with macros over macros.

But I suspect you never hear of so many questions about "retro antagonist polymorphic macros over monadic functional arrowd", because people give up at "how do I import a lib to make an http call" ?

- a single, standard and opinionated way to lay your frigging files on your effing disk. "cargo new". And, no, it should NOT require people to create a top level "common-lisp" folder to store all their projects.

- adding and loading deps. Sorry, typing quicklisp:xxxx in every repl session you open is not "cargo add".

- a baked in way to run some sort of unit test suite. Have dozens of options if you want, but what is the "cargo test" ?

Of course all those problems have been solved by various tools somewhere in 1997, so it will sound like an "entitled millennial" comment.

But, soon, the tagline to aim for will be "a lisp for the 100 years of lisp". What's that ?

spdegabrielle3• 5 days ago

You might like Rhombus. Nice compiler. Uniquely extensible and easy to learn syntax. https://rhombus-lang.org/

vindarel3• 5 days ago

So let's try: SBCL with

* [clj-coll](https://github.com/dtenny/clj-coll) - Clojure collection and sequence APIs in Common Lisp, with optional Clojure collection syntax.

  * provides immutable Cons, Queue, PersistentList, capabilities as well as Vector, Set, and Map analogues built on FSet (but accessed entirely via Clojure APIs).

  * optional read syntax so you can type `{:a 1 :b 2}`, `#{1 2 3}`, and `[1 2 3]`.

* [clj-con](https://github.com/dtenny/clj-con) - Clojure-style concurrency operations in Common Lisp.

* [clj-re](https://github.com/dtenny/clj-re/) - Clojure-style regular expression functions.

* [clj-arrows](https://github.com/dtenny/clj-arrows) - Clojure-compatible threading/transformation/arrow macros for Common Lisp.

editor: https://coalton-lang.github.io/20260424-mine/

type system: Coalton

Octplane• 5 days ago

I came here to see Janet mentioned and I am a bit sad :)

https://janet-lang.org/

dmux• 5 days ago

I'm surprised there's no call out highlighting Common Lisp and Clojure's "liveness" compared to Racket (and Scheme). Racket is "batch compiled" wherein CL and Clojure you're editing a live image.

SilentM68• 5 days ago

Racket's top dog in my book :)

zem4• 5 days ago

apart from anything else it has a really beautiful object system. I feel like racket and ocaml are two languages where the object system doesn't get enough love.

lgrapenthin• 5 days ago

Choose any LISP, and the right LISP will choose you.

xvilka2• 5 days ago

CommonLisp really should evolve to update the language up to the modern standards and become more functional and better typed.

kanbankaren• 5 days ago

It is already typed. Types are optional. I think types have been available for the last 30 years? Check the specs.

xvilka2• 5 days ago

I wrote "better typed", not just "typed".

tmtvl7• 5 days ago

It is typed, but it's not very well typed. List is 'null or cons' for instance, not 'null or (cons * list)'. Also lack of generics so you can't have a class which holds an element of a generic type which can be determined later on in the compilation process (e.g. a weight-balanced tree which holds elements of a given type).

avph• 5 days ago

I recently started looking at https://github.com/elle-lisp/elle . It's made with AI but has an interesting feature set.

ozhero• 5 days ago

For someone who knows nothing about Lisp I found this an excellent article.

Motivates me to learn more about Lisp (and Clojure)

vindarel3• 5 days ago

Common Lisp lacks some conveniences that have become common in newer languages, such as concise literals for a wider variety of data structures, persistent immutable collections, lazy sequences and built-in general-purpose pattern matching.

we can explore libraries on https://github.com/CodyReichert/awesome-cl/

concise literals: serapeum's dict or other libraries bring you { } for hash tables and the like.

persistent collections: FSet (and more)

lazy sequences: series, gtwiwtg (generators) (and more)

pattern-matching: Trivia

many libraries are shipped in CIEL: https://ciel-lang.org/ (shameless plug)

---

It’s currently used in …

more example companies: https://github.com/azzamsa/awesome-lisp-companies/

also: https://lisp-screenshots.org/

---

at the cost of slightly slower startup times

that means ±30ms, not the Java-esque slow startup time ;)

---

editors: don't miss https://lispcookbook.github.io/cl-cookbook/editor-support.ht... and the new Mine, OLIVE for VSCode, ICL repl (terminal and browser).

birdfood• 5 days ago

I'm really quite drawn to lisp (in general) but I keep bouncing off it. I think the main reason is I just don't know how to effectively work with a dynamically typed programming language. I think for me the affordances that a language provides to change a program over time matter much more than the features that aid in writing programs. I want to know before I run my program whether my program is sound. I appreciate what other people are able to do with lisp(s) and I want to experience that for myself. But I think what I need is to let go of having a compiler yell at me when I remove a field from a type but that I still have functions that expect that field (for example). Is it just more tests? Live REPL editing? It seems like this can only cover so much surface area compared to compile time type checking. I don't think statically typed languages are better than dynamic ones or vice-versa. I just am not as effective with the dynamic ones.

jasonm232• 5 days ago

Really should include Emacs lisp, as it's a something many in academia happen upon for LaTeX or some other side use.

While Emacs Lisp is confined to the editor, it also shows that the Editor is not that, and much has been said of it as an OS, an Application Platform, and so on.

Since about 1992, I've used it as platform for many things as well as a general purpose text editor I couldn't initially figure out how to quit.

I'm sure many here are more fervent about Emacs, living in the terminal switched to living in Emacs for a lot of folks... that's really a testament to the usability gravity of an integrated computing platform with Lisp as it's only scripting language.

ymmv of course

jiehong• 5 days ago

It does, calling it Elisp

jasonm232• 5 days ago

That'll teach me not to scan the article before posting.

again.

cyrc• 5 days ago

For those who are interested in common lisp

There is a very nice IDE called Mine

https://coalton-lang.github.io/20260424-mine/

iFire2• 4 days ago

Anyone have lisp commentary on https://github.com/janet-lang/janet?

A Road to Lisp: Which Lisp

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