A road to Lisp: Why Lisp

https://scotto.me/blog/2026-07-09-why-lisp/

by silcoon • 14 days ago

299 311 14 days ago

AlexeyBrin2• 14 days ago

The website seems to have a bug with syntax highlighting. Pieces of code included in the post text are black, you can still see the actual text if you select it with your mouse. Same bug on Chrome desktop and on Safari on iPad

jdw64• 14 days ago

metoo

dsizzle• 14 days ago

My first thought was that the article was redacted lol

hermitcrab• 14 days ago

I get this on both FF and Chrome.

cjm42• 14 days ago

This is the classic example of why you should always set the foreground color when changing the background color. Otherwise you end up with <code> blocks that are black-on-black. It probably works fine if your browser is in dark mode.

A workaround is to open one of the code elements in the browser's debugger and add color: white to the :not(pre) > code style.

harshreality• 14 days ago

MacOS Chrome? The code blocks look fine to me in linux {firefox, chromium, brave}. I think they're all using Qt.

lgas3• 14 days ago

Looks fine to me in Chrome on Mac.

AlexeyBrin2• 13 days ago

Now, it looks fine to me too. I tested it in Chrome,Firefox, Safari on macOS and on Safari on an iPad yesterday when I wrote my comment and in all cases there were black lines all over the the place. The author corrected the problem, see https://news.ycombinator.com/item?id=48855382

silcoon2• 13 days ago

Thanks for reporting. I fixed the error as soon as I read your comment.

sroerick• 14 days ago

I must admit - I still don't understand macros. I get that they're code that's generated at compile time. But I don't understand how that's different than a function which evaluates other functions. I guess the latter would actually be evaluated at runtime? I think I get it conceptually but I'm not sure I have the muscle memory to reach for them. Anybody here have an "ah hah!" Moment with macros?

wild_egg3• 14 days ago

There's a bit of a mental model flip to make maybe.

they're code that's generated at compile time

They're code that generates code at compile time. Macros can actively walk the AST of the parameters they process and rewrite them completely into new shapes. That transformed AST is what then actually gets compiled.

efficax• 14 days ago

Sure, macros are functions that take functions as input, and produce new functions as output. But they take the function's symbols as input and produce a new set of symbols. So a macro can extend the syntax of the language without having to modify the core language system. Anyway, what's unique about Lisp macros vs say, Rust macros, or C style preprocessors, is "homoiconicity". The data structure that a Lisp macro takes as an input, the lisp code, is the same data structure that the language uses normally (S-expressions, lists...), so writing a macro requires few new language skills compared to writing normal lisp (again, compare writing Rust macros, a dark art in comparison).

gf00022• 13 days ago

At the same time, you get a mushy tree as input, instead of a properly typed AST "object" with accessible "function name", "method parameters" everything that you can just refer to.

It will be the third arguments' 2nd arg with s-exprs, following your arbitrary pattern you figured you want to use. So it's very arguable which is easier to use, sure for some "party tricks" lisps will win, for anything more useful my vote would go with rust/Scala macros for sure. So again, you win nothing by homoiconicity, the by-the-compiler implemented parse function is more complex in rust, which is 100% abstracted away.

jtara1• 14 days ago

You could use them to:

1. Come up with an algorithm to define an algorithm.

2. Code expansion. Instead of typing out 1000 classes that are best represented as a template of a single class, you can define a macro then use it.

3. C++ at least uses them to provide generics.

4. They let you peel back the layers of abstraction to use the language itself as an API. Useful if you want to write static analysis to do analysis on code quality, security, linting, etc.

5. Anything you can imagine, it's metaprogramming.

lucyjojo• 14 days ago

one way to see it is that it's a function that runs at compile time. for instance instead of dumping magic numbers/tables in a codebase you could put the code and substitute to their value at compile time.

but also it can change your code, so you get to do all the java annotation magic stuff.

Jtsummers5• 14 days ago

If you haven't read it, I'd suggest taking a look at Paul Graham's book On Lisp [0]. He says better, and with more examples than I'd provide in a comment block, what I'd write on the subject. Jump to chapter 8 for his discussion on the topic, referring back to chapter 7 if you find the macro definitions difficult to read.

[0] https://www.paulgraham.com/onlisptext.html

taeric2• 14 days ago

If it helps, https://taeric.github.io/CodeAsData.html was my attempt at exploring "code as data" and what makes lisp different here. My specific focus was more to point out that "eval" in lisp doesn't just take in a string. But I think the same general points remain.

BoingBoomTschak• 14 days ago

Macros are conceptually similar to FEXPRs in that they act like functions that don't evaluate their operands and return code. The (only?) difference is that macro are all expanded before execution/runtime.

timonoko3• 14 days ago

You do not need macros for anything. They are not the tool to "extend the language", but instructions for the compiler. And if the system does not even have a compiler, macros are useless, often incredibly stupid.

kazinator5• 14 days ago

If you have an interpreter only, no compiler, using macros for metaprogramming anwyay at least prepares you for the eventuality that one day there will be a compiler. The macros will Just Work as before, only the expanded code is now processed by compiling.

Suppose you reject the idea that there will ever be a compiler. Macros are still useful for doing "compiler-like things" in the context of interpretation, like transforming code into something that will interpret better.

We can regard the interpreter as a virtual machine acting on a representation of the code; the macro system lets you manipulate the representation in a pre-computed pass, which has no further cost at run time.

If you have a code expansion pass on top of an interpreter, for supporting macros, you can use that as an excuse to perform built-in code transformations that are not macros; those enable you to have more flexibility in how special forms are implemented.

In TXR Lisp case is a macro (family) which performs certain optimizations like recognizing values in a range and emitting a table switch. This works interpreted or compiled:

  1> (macroexpand '(case x (1 'a) (2 'b) (3 'c) (4 'd) (5 'e)
                           (6 'f) (7 'g) (8 'h) (9 'i) (10 'j)))
  (let ((#:test-0005
         x)
        (#:swres-0007
         '#:nohit))
    (and (integerp #:test-0005)
      (<= 1 #:test-0005
          10)
      (sys:setq #:swres-0007
        (sys:switch (- #:test-0005
                       1)
          #(('a) ('b) ('c)
            ('d) ('e) ('f)
            ('g) ('h) ('i)
            ('j)))))
    (if (eq #:swres-0007
            '#:nohit)
      (progn) #:swres-0007))

It is faster to do some checks and interpret the sys:switch special form to dispatch by a numeric index than to do a large number of exhaustive comparisons.

Ultimately, the way we optimize interpretation is by compiling, but it can still be worth it to have better interpretation here and there.

You don't want to do this kind of optimization at run-time; you don't want the interpreter to be evaluating the condition "are these cases integers (or characters) in a tight range?". That's a property of the syntax in which the cases are constants; it wants to be pre-computed once.

erichocean2• 14 days ago

The arguments presented to a macro don't have to be valid code. Your "function evaluating functions" are all individually valid functions you've composed at runtime.

    (defmacro foo [code] ,,,)
    (foo "<some totally different language in a string>")

=> actual, compiled Clojure function built up by `foo` parsing the string, producing a Clojure list, and calling `(eval the-list)` and returning it.

I passed a string to `foo` in the example, but it could actually be anything the Clojure reader can parse even if it is semantically invalid—arbitrary Clojure data.

aidenn0• 14 days ago

Many problems can be solved with either macros or higher-order-functions. The advantage of macros is two-fold (macros also have disadvantages, and Lisp allows you to use either solution; deciding which to use is often a matter of taste):

1. Syntax can be more familiar

2. Performance (to the extent that there is overhead for functions-calling-functions).

For example, let's consider a hypothetical lispy language that doesn't have a short-circuiting "and" operator. Macros would let you implement something to used like this:

  (and (foo x) (bar y))

Higher order functions would require you to do something more like:

  (and (lambda () (foo x) (lambda () (bar y))

More noise, and more work for the optimizer (or in the worst-case, more work at run-time). Languages that rely heavily on higher-order-functions will tend to have terser syntax for anonymous functions. For example in javascript you might do:

  and(()=>foo(x), ()=>bar(y))

BeetleB4• 14 days ago

But I don't understand how that's different than a function which evaluates other functions.

You want a function that takes in arguments, but does not evaluate the arguments when called. So:

   func(foobar(), foobar())

Normally, foobar() will be called twice - at the time of the call. With macro expansion, you can ensure that it's not the result of calling foobar that goes into the func, but this expression.

A canonical example is if you want to write an if/then/else function:

    if(condition, then_path, else_path)

It's quite possible that the else_path is invalid and will terminate the program if the condition is true. But if you wrote a function this way, it will evaluate both then_path and else_path - not something you want to do in a regular if expression!

janalsncm2• 14 days ago

(I think you meant “if condition is false”)

Technically you can accomplish the same thing in languages with first class functions if the caller wraps their code in a lambda.

frwrfwrfeefwf11• 14 days ago

Open notepad and solve your problem in some language you make up on the fly, with macros that's now valid lisp code. A macro is a compiler and nothing more.

hajile3• 13 days ago

function can do what a macro does, but it must run every single time while the macro can run just one time during the final code generation.

Let's say you have some Java-style a + b. It needs to work on native strings (concatenation) along with various kinds of ints and floats. The issue is that each one of these works differently internally, so the system is going to look at the incoming symbols and metasymbols (inferred type data) and is going to dynamically change between different functions like ADD_STR, ADD_INT8, ADD_INT32, ADD_FLOAT32, etc. If it did this at runtime by introspecting the type with some `switch(incomingType)` statement which involves all kinds of extra data and branches that clog the cache and create branches (two of the worst things you can do for performance). Instead, the macro (though they probably don't call it that) looks at everything and hardwires the correct output.

This hardwiring and its associated performance is the difference between a function and a macro. A macro `foo!(a b)` can inline into the current function while the function alternative must save all the registers to the stack and create a new stack frame which is very expensive.

The beauty of lisp macros is how functions and macros look the same. You may think that `(+ a b)` is the same as your favorite languages' `a + b`, but most lisps also allow `(+ a b c)` too. `+` is a macro rather than a function and it knows that `(+ a b c)` needs to convert to something more like `(+ a (+ b c))` and a typed lisp may go further to something like `(+f64 a (+f64 b c))`.

_ph_2• 13 days ago

I think the best explanation, how Lisp macros are different from most other macro system is, that a Lisp macro is a function executed during compilation. It gets fed the parameters passed to it in literal form and then computes the source to actually compile by the compiler.

The power of this is that this function is also written in plain Lisp and it also sees all definition already existing in your Lisp image. Also, it is completely unlimited in power. So while being run, or as it is called "during macro expansion" the function could google for one of the things passed and use the result to create the output. Of course, this is not a practical example, but shows how flexible the system is.

arikrahman2• 14 days ago

All roads lead to Lisp

sph5• 14 days ago

What has Lisp ever done for us?

arikrahman2• 14 days ago

The aqueducts!

vindarel4• 14 days ago

Flight search (Google's ITA Software), underground planning (SISCOG), CAD software (PTC Creo et all), the Gollum face (Mirai), automation of document extraction, renewable energies resource planning (3E), project management (planisware),

games (Kandria),

Maxima,

a faster pgloader (https://tapoueh.org/blog/2014/05/why-is-pgloader-so-much-fas...),

hackernews (was rewritten to SBCL: https://lisp-journey.gitlab.io/blog/hacker-news-now-runs-on-...), first reddit…

https://lisp-screenshots.org/

https://www.lispworks.com/success-stories/

also Emacs (for another dialect).

iLemming27• 14 days ago

What has Lisp ever done for us?

phanitathion, roaphs, aqueduphs, mediphine, wphine...

I'm sorry. Couldn't resist - I watch Python and do Lisp. Or the other way around, sometimes. And, no, I'm not from Barthselona.

kazinator5• 14 days ago

It's acted as a road-concentrating hub to simplify logistics.

pjmlp5• 13 days ago

"We were not out to win over the Lisp programmers; we were after the C++ programmers. We managed to drag a lot of them about halfway to Lisp."

- Guy Steele, Java spec co-author

"35 years of Lisping at SISCOG"

https://www.siscog.pt/en-us/blog/35-years-of-lisping-at-sisc...

https://en.wikipedia.org/wiki/Emacs

https://help.autodesk.com/view/OARX/2024/ENU/?guid=GUID-A0E9...

https://en.wikipedia.org/wiki/Game_Oriented_Assembly_Lisp

zbentley3• 14 days ago

There are some truly powerful and unique things about Lisps, but I wish articles like this would stop including REPLs and hot-reloading. The former have been table stakes for interpreted languages (and some compiled ones!) for years, and the latter is neither unique nor particularly widely used (hot reloads have to tangle with state and patching, so resetting the world for ease of reasoning is considered a best practice for a reason).

taeric2• 14 days ago

Largely agreed.

I do think it is worth highlighting how many advanced parts of hot-reloading have already been covered in Common Lisp. Same with highlighting how the REPL is largely not used to directly type into, but is instead a very powerful interface for tools to interact with a running image.

But, again agreed that simply these existing are not that notable today.

spinningarrow• 14 days ago

The former have been table stakes for interpreted languages

I used to think so too back in the day when I was getting into Clojure. It was much later when I realized that when Lisp people talk about the REPL they’re usually talking not so much about the interactive CLI where you can evaluate commands easily but more so the ability to connect your program to a live session where you can quickly evaluate forms within your text editor and in the context of your running application, which enables much more interactive development than in other interpreted languages.

dismalaf7• 14 days ago

You've been able to do this in Ruby since I can remember. Not a lot of editors take advantage of it though...

lurkercodemnky• 13 days ago

you can do that in a python debugger?

jolt42• 14 days ago

But with Clojure and immutable by default, hot reload is a real thing, it sounds like not just on JVM but even among lisps.

veqq• 14 days ago

Clojure barely let you import packages without restarting the JVM recently in its life.

KingMob2• 13 days ago

Ehh, no. In fact, other Lisps are actually slightly better at hot reloading because they're not hampered by the JVM's limits.

Check out stuff like CHANGE-CLASS or whole image loading.

kazinator5• 14 days ago

Not all Lisp dialects have well-developed hot patching systems. The OOP system has to be carefully designed for it. What if a class definition is superseded by a reload, but there are existing instances? The Common Lisp dialect of Lisp has useful answers to questions like this, but not necessarily every Lisp you come across.

Even Bash supports hot-reloading. I've developed modules that are updated in place by sourcing:

   $ . /path/to/script.sh

munificent• 14 days ago

and the latter is neither unique nor particularly widely used (hot reloads have to tangle with state and patching, so resetting the world for ease of reasoning is considered a best practice for a reason).

For what it's worth, hot reload is very widely used in Dart/Flutter. When you are writing UI code using a reactive style framework where rendering the UI appears to be "generate a new UI from scratch on each frame", it's more straightforward to have an intuition about what does and doesn't get reloaded.

It's not perfect, of course. But it works really well for the kind of changes you make when iterating on a user experience.

ux2664784• 14 days ago

Generally speaking, the pain of handling hot patching depends highly on the structure of your codebase and the reason for hot patching to begin with. For a structure-of-arrays architecture, or for fixing logic errors at run-time, it's really no big deal at all.

It is limited utility, but if you start out from the mindset it's something you'll use a lot, those limitations start disappearing rather quickly.

BellsOnSunday• 14 days ago

I thought this was going to be https://web.archive.org/web/20120106121645/http://wiki.alu.o.... Brings back memories of following comp.lang.lisp, not least as a sort of soap opera. Lots of characters and drama, as well as programming wizardry.

GMoromisato8• 14 days ago

Programming is in tension between the Light Side and the Dark Side.

The Light Side is about preventing the programmer from making mistakes: Get rid of go-tos! Add static types! Do not allow a bug to be expressible. The Dark Side is about giving power to the programmer: Macros? Obviously. Operator overloading? Self-modifying code? Multi-line reg-exps? Go to town!

The Light Side knows programmers are flawed and imposes constraints. The Dark Side trusts programmers with power. Neither side is correct all of the time, and a good programmer learns both.

Lisp is interesting in that it is clearly Dark Side programming (the programmer can do anything) but it's still admired by Light Side programmers. Maybe there's something about the simplicity of the language that makes it seem platonic--almost incorruptible. Or maybe Lisp is so pure that it embodies both Light Side and Dark Side, like a god that spawned the programming universe.

rogue7• 14 days ago

Kind of agree, but in my view preventing the programmer to make mistakes is futile. I have seen awful stuff in languages made to prevent errors.

It's much better to give all the power to the programmer, to allow him to fix his mistakes rather than fantasising about preventing them.

pfdietz• 14 days ago

I'm not big on static type checking in most situations -- adequate testing should find the type errors too -- but one place it looks very useful is avoiding data races in multithreaded programs. See Rust.

malkia3• 14 days ago

Hah, didn't think of it this way... To me it was if it allows live updates (+support for them) or not :)

busfahrer• 14 days ago

Or maybe Lisp is so pure that it embodies both Light Side and Dark Side, like a god that spawned the programming universe.

This isn't so far off, considering that some people consider the "Lisp in Lisp" bit from the 1.5 manual to be the "Maxwell's Equations in Software":

https://michaelnielsen.org/ddi/lisp-as-the-maxwells-equation...

GMoromisato8• 14 days ago

Maybe machine language is the formless chaos and Lisp is the purest manifestation of order. All other languages are points in between.

DonaldFisk• 14 days ago

I have always assumed that Alan Kay compared Lisp to Maxwell's Equations because of the similarity between the interplay of eval and apply in Lisp on the one hand, and the interplay of the electric and magnetic fields in Maxwell's equations on the other.

patrickmay• 14 days ago

I like your metaphor but I'd argue that trusting programmers with power is the Light Side.

Relevant PG: https://paulgraham.com/langdes.html

GMoromisato8• 14 days ago

That's a great essay--thanks.

And you have a good point. Maybe it's a weakness in the metaphor if one can see it either way.

I fundamentally believe that there is no perfect language, instead one merely chooses a set of trade-offs. What's interesting about Lisp is that it is simultaneously well-respected and yet not widely used in productions (compared to C, C++, Python, JavaScript, and even Rust).

It's almost like Lisp chose a particularly extreme set of trade-offs that yield great power but also repel large swathes of programmers. I think PG might say that it repels dumb programmers, but maybe not.

Barrin92• 14 days ago

for a while there's been a strong cultural tendency in programming to mistrust people and trust tools (often even blindly because tools are just assumed to make no mistakes), and so expressiveness has been sacrificed for safety. There can be something to this but it's also self-fulfilling, if you strip people of agency of course they'll unlearn to program.

I've always thought it's a misanthropic philosophy and sucked much joy out of programming but also there's something to be said that there's safety in the expressiveness of Lisp. I read an article a while ago that found a robust correlation simply between length of a code base and errors regardless of languages used. And given how succinct and clear Lisp codebases can be that's valuable in itself.

we're kind of at the logical endpoint of this now with gigantic slop codebases that nobody understands just held together by 20 different tools, and if you ask me if I had to pick one of those or something one tenth the size written by a guy or girl who has been writing Lisp for ten years I'd say thank you I'll go with #2

coliveira• 14 days ago

The issue is also social, the average software engineer will treat Lisp code as a liability because most people really don't know what to do with it. In the mind of a professional SE, code is "maintainable" only if it's writing in Javascript or some other commercial language.

adamddev1• 14 days ago

I think the big thing is that Lisp is (aside from mutable variable assignment) basically all declarative, rather than the imperative paradigm.

Even without static types, and even allowing macro craziness, there's just such a stronger baseline of declarative and functional thinking, you're off to such a good start in clearer thinking and reasoning about a program.

enfield-argent• 14 days ago

I think this depends on the Lisp, no? AFAIK Common Lisp supports a lot of imperative style programming--besides all the mutation/assignment functions, there's the `prog` macro that lets you use goto, `do`/`do*` to iterate over groups of statements, or even the `loop` macro. OTOH the Scheme-style Lisps are much more declarative thanks to TCO and a community that prefers the functional/declarative programming style.

But again, I suppose all the Lisp forms return values, and quibbling about the declarative : imperative :: expressions : statements mapping is just petty semantics

ludston2• 14 days ago

This is just not true. The Lisp family contains all conceivable variants of languages, from statically typed Coalton, to dynamically typed Scheme. From functional, immutable by default Clojure to the imperative-style of Common Lisp.

There are prologs, constraint solvers, ffis, JavaScript alternatives, garbage collected and not garbage collected languages that call themselves lisps.

tikhonj2• 14 days ago

It isn't nearly as much of a trade-off as people say. Languages like Haskell are both remarkably expressive and provide a lot of safety. (And, of course, languages like Python, Java and Go are the opposite.)

GMoromisato8• 14 days ago

Haskell is currently at #18 in LangPop: https://langpop.com/rankings

Almost by definition that implies that it makes some trade-offs that turn off lots of programmers. Still more popular than Lisp, though.

frwrfwrfeefwf11• 14 days ago

Typical ignorant take. Lisp macros allow you to create restricted DSLs to prevent bugs from being expressible, including full static type and structured programming systems. Basically no one understands this until they reach the 'lisp enlightenment', so the decades of beating this drum falls on deaf ears. AI is here now so it's time to let it all go.

GMoromisato8• 14 days ago

Of course you feel this way. You just finished reading SICP or maybe you binged PG essays last weekend. But eventually you'll read Simon Peyton Jones and start screaming about functional programming and algebraic type systems. Then, if you're lucky, you'll get a real job and realize that languages are just a tiny part of software engineering.

I'm excited for you to experience that journey.

ux2664784• 14 days ago

In an awkward, error-prone, non-mathematically rigorous and easily subverted manner. That whole "make invalid states unrepresentable" thing relies upon the fact the semantic structures you're doing it with can't be shadowed silently by other parts of the code, and the safety constraint itself is guaranteed to be completely pure and deterministic. Lisp macros and reader macros fail at that criteria. They aren't any different from any other collection of procedures and their collective interface. Actually, they're a fair bit worse since the natural cognitive overhead from juggling multiple layers of evaluative indirection lends itself to blindspots of edge cases and unsoundness.

I think "macros are a safety mechanism" might qualify for the top 3 "new lisper mania" things I've ever read.

gf00022• 13 days ago

This is the "fallacy by Turing completeness".

Sure, and you may as well write full systems in Minecraft and create your own type system inside and whatnot.

Macros can make some small specific uses safe, indeed. But they are not comparable to languages with type systems where everything is type safe, unless you literally have written a new type system and compiler to begin with. Which is trivially true in every other language, C can be 100% safe with a much better type system, I just read a text block and compile it as rust code! Wow!

dreamcompiler• 14 days ago

I think of C as more of a dark side language because it's basically a portable assembler. Lisp at least prevents you from doing the stupidest things like overrunning array bounds or writing to freed pointers*, which C is perfectly happy to let you do.

* Of course there are no user-visible pointers** in Lisp so the concept of free vs. not free doesn't come up because memory allocation and garbage collection are automatic.

**Under the hood most everything in Lisp is a pointer, but the user cannot see them or mess with them.

throwaway815238• 14 days ago

Lisp generally has precise GC, which I'd say makes it light side. It's even relatively type-safe if you count runtime type-checking.

Highly reliable systems are written in Erlang, which if you squint is another Lisp dialect. There's even a sexp-based version called LFE, for Lisp-flavored Erlang. Erlang's key to reliability is error recovery, rather than exceptional levels of error prevention.

I do like your light side/dark side classification.

gf00022• 13 days ago

If you squint enough, JS is a lisp..

Define a goddamn language, syntax is not enough to define one! What are the semantics? Without that you are just talking about syntax trees like they would mean anything

sph5• 13 days ago

Erlang, which if you squint is another Lisp dialect

Prolog disagrees. IIRC the first versions of Erlang were written in Prolog, and you can still see its influence in the syntax.

akkartik• 14 days ago

You mixed up Light and Dark. Creator-knows-best bondage-and-discipline is the Dark side. Trusting people with power is the Light side.

sph5• 13 days ago

Light and dark is propaganda depending on which side you're on.

I'm with you, on the dark side I've seen people slowly turn into crabs, screeching about memory safety and static types. Can you imagine that? Now stick those wings on me, I'm going to fly close to the sun.

tyeaglet• 14 days ago

Only if you knew the power of the Lisp side…

James_K• 14 days ago

I dislike when people use the term “power” to describe making code slightly shorter to type. Operator overloading is not in any meaningful sense more powerful than a language which lacks it.

never_inline• 13 days ago

With operator overloading you can provide same numeric operation interface to library types such as big integers. Sure, you can also define methods and make sure your primitive types also define those methods but now you have some confusions (like equals vs == in Java).

gf00022• 13 days ago

I agree with you on overloading - the real word here should be "expressivity", which is defined by language constructs that could NOT be syntactic sugared into a local context. Those may occasionally be useful, though not by itself. E.g. gotos are more expressive by the above definition, yet it was largely deemed to not be a useful "power".

adrian_b2• 13 days ago

You say that because you lack experience in writing programs for scientific-technical computing, where an abundance of complicated mathematical formulae are necessary.

Most programmers have seen only programs that do more data movement and comparison than actual computation, but nonetheless there are programs with abundant computations, the kind of programs that were originally written in Fortran, but nowadays they may be ported to other languages, or alternatives for them may be now written in more modern languages.

In such programs, overloaded operators do not make programs "slightly shorter to type", but they reduce the amount of text at least an order of magnitude or even much more.

The main advantage is not that you type less, but that you can read the source of some function in one page, so you can see it in its entirety, instead of having the source spread on many pages, forcing you to wander through all those pages continuously, when you try to understand what it does and whether it does it correctly.

I have written such programs, for instance which were full of long formulae where most variables were complex vectors or complex matrices (for computing some radiated electromagnetic fields with the method of boundary elements). Without the operator overloading of C++, reading them would have been extremely tedious and maintaining them would have been very error prone.

For myself, any programming language that lacks operator overloading, e.g. Java, is disqualified, because it definitely is not "powerful" enough.

Operator overloading also increases the safety of a programming language, because you can define distinct data types for each kind of physical quantity, allowing the compiler to detect and reject the invalid operations. Without operator overloading that would inflate too much the size of the source text.

GMoromisato8• 13 days ago

Maybe you've never been in a codebase that overloads the comma operator.

user3939382• 13 days ago

Check out Clojure spec. The light dark bifurcation doesn’t hold up.

sdfsfdsdfs3d4• 13 days ago

Do not allow a bug to be expressible

That is a very powerful idea, but unfortunately it cannot be realized with a fixed set of language rules. Some invariants are universal, but some are bound to the domain. Some projects require, say, an int (EvenInt) to take on only even numbers and others odds (OddInt). You can imagine the possibilities here are unbounded ("the numbers should be prefixed by numbers that are divisible by my age squared").

Ideally your base language has the expressive power to formulate new abstractions and constraints. This fundamentally requires the Dark Side. Once the proper primitives are in place a different "language" - this can be literally or figuratively - is used to express the interplay between those primitives.

In effect you are starting with the most general (say, all of Lisp), restrict it to become more and more and specific - only "these modules" - until it cannot be reduced any further. If you can bring your domain down into being expressible as, say, a single config file, that'd be quite ideal. If you don't need the powers of abstraction to express your solution then exposing said powers would only invite in trouble. The mathematical equivalent of introducing unnecessary variables.

As a programmer you are free to traverse the journey from say all of Lisp to a JSON config file in whatever way you please.

The "Light Side" people have converged, or try to converge, on some intermediate state between full powers of abstraction and configuration only. I think this is useful because many if not all problems travel through that intermediate landscape on the way "down" (into their specificity). For example what you call "types" is a significant restriction on your freedom but at the same time it's so enormously general that this restriction can be considered a worthwhile default because just about any problem I can think of can potentially benefit from that restriction.

All this is to say that I don't think it's a dichotomy so much as two interacting polarities whose interplay gives each its strength.

Lisp is a particularly minimal base introducing very few restrictions of its own. But it's not the only one. Forth would be one in another direction.

psd13• 13 days ago

Well put. Minor quibble: I see what you're driving at with "inexpressibility" but i think i could write EvenInt and OddInt in F#. I don't know Haskell, but i believe you would have to work hard to find a domain constraint that you can't declare in the Haskell type system.

frwrfwrfeefwf11• 13 days ago

you understand. It's also endlessly funny to me it requires anonymous accounts to speak the truth about programming languages.

sdevonoes• 13 days ago

But there are two types of “programming”: 1) programming per se (just you writing code for fun and perhaps building your own tools) and 2) a team of people with real-world constraints writing software for others for revenue

It’s clear why it feels so good to use something like Lisp for personal projects. It’s also clear why the vast majority of companies don’t use it

astrobe_2• 13 days ago

I'll paraphrase someone who commented on HN once (about dynamic vs static typing, IIRC): permissive languages are enablers for solo programmers, but you need more restrictive languages for team programming.

This matches my experience because you don't chose who you work with. Skill level is uneven among the team. Less skilled co-workers will make mistakes that will have more consequences when the language is more permissive.

That's one of the reasons you want code reviews, but then you convert your skilled programmers to teachers. This is not a good trade, because the time they spend improving the skills of other programmers is partially wasted because programmers are free to come and go. AI could change this picture.

The name of the game is therefore to keep your teams small and skilled, but this is can be difficult because of typical company politics - e.g. "bus factor" considerations, shortening time-to-market is often achieved by adding more programmers.

oalae5niMiel7qu5• 13 days ago

This matches my experience because you don't chose who you work with.

That's what job interviews are supposed to be for. It should be easy to hire only the most skilled programmers, especially with the massive number of unemployed programmers out there right now.

xedrac• 13 days ago

Less skilled co-workers will make mistakes that will have more consequences when the language is more permissive.

Even the most skilled engineers are going to make these mistakes sometimes. That's the whole point of more restrictive tooling, and why Rust has exploded.

Don't get me wrong. I love Lisp, and use it in some personal projects. But I wouldn't want to use it in must not fail scenarios unless those situations can wait for a human to fix the running image.

GMoromisato8• 13 days ago

I agree with you. Though I wonder if the divide is more about the size of the program. I've got a couple of large (>100K LoC) solo projects and I like using C++ because it is much easier to catch bugs at compile time.

Static typing is a huge advantage in refactoring, and if you don't refactor a large program as it grows, you end up with a mess.

plumbees• 1 day ago

If the more skilled programmers become managers, then it's theoretically their job to become teachers, as their goal is to be force multipliers as opposed to people who can't delegate and accept a lower quality (temporarily) in exchange for higher throughput later.

bryanrasmussen• 13 days ago

Programming is in tension between the Light Side and the Dark Side.

The Light Side believes in giving people freedom and power to achieve freedom, to allow themselves to express themselves better through programming, to become better programmers through the tools the light side provides; in the Light Side believes in programming as a way of thinking.

The Dark Side believes that people are incapable of handling freedom and must be restricted and controlled under the service of various organizations - generally companies. The companies will control access to programming and control the programmers via this access. The dark side does not believe in making programmers better programmers, it believes in managing programmers. The dark side does not believe in helping programmers to think, it believes in thinking for them.

oalae5niMiel7qu5• 13 days ago

You have it inverted. Your "Light Side" is what previous generations of programmers called "Bondage and Discipline", because this philosophy assumes that a good programming language has built-in shackles to impose the will of a so-called "benevolent dictator" on all programmers.

agumonkey3• 13 days ago

it's dark side-ish at the ast level mostly, which is not the same as the dark side of mutable state over byte arrays

yogsototh• 13 days ago

I wonder what side you would put Malbolge,

What side for python? Haskell? Idris? Clean? C? K?...

white/dark side is too much of a simplification to me.

Programming language equilibrium is a very complex subject and fascinating one.

After years of experimenting with many of them, it is all a matter of context of usage, personal preferences, objectives, etc.. there is no such thing as "the best programming language ever", neither "best for light side programming" nor "best for dark side programming".

Similarly, there is no such things as: Light side/Dark side in artistic painting. There are tons of paints some are clearly greater than others, but there is no such thing as "the best painting most beautiful for everyone seeing this paint comparatively to any pain".

[^Malbolge]: https://en.wikipedia.org/wiki/Malbolge

[^Clean]: https://en.wikipedia.org/wiki/Clean_(programming_language)

[^K]: https://en.wikipedia.org/wiki/K_(programming_language)

eimrine• 13 days ago

Malbolge is not an instrument for building, come on programmer.

C is clearly the dark side with to chance to protest.

The only way to consider K as dark side is its speed constraints relative to my favorite PL which is J. K is so fast because its interpreter fits into CPU cache.

Haskell is a border case between sides because the idea of PL is so light that using so much light in programming leans to be really dark. Haskell extracts the cognitive friction from the code environment to the types environment, programming in paper is not a joke for Haskell.

dosisking3• 13 days ago

Python is definitely Light Side

malkia3• 14 days ago

I've been wondering - Is lisp (common lisp, clojure, scheme) easier for iterative work with LLMs?

gentooflux• 14 days ago

I've found LLMs to be bad at balancing parenthesis. I've also found them to be less likely to hallucinate library types in dynamic languages, they tend to hallucinate arguments to library functions/methods instead.

iLemming27• 14 days ago

LLMs to be bad at balancing parenthesis

Because you treating Lisp just like any other (non-homoiconic) PL. Give an agent a true Lisp REPL to mess around, and you'd be surprised. Things get very interesting. I still don't understand why more people don't do that - isn't that obvious first thing anyone should figure out? Like I can't even imagine working with Lisp without a REPL and structural editing - I'd immediately fail at balancing parens. Why do you expect a [dumber] machine would do any better?

mechanicum• 14 days ago

I've found LLMs to be bad at balancing parenthesis.

I think that was true last year. In my experience, it’s no longer the case with Claude Code or Codex.

frwrfwrfeefwf11• 14 days ago

assuming you're using state of the art llms, when they start failing with paren balancing it means they're approaching the limits of their context window and a new session should be started.

klibertp4• 14 days ago

Depends very much on your harness and effective use of tools. For vibe-coding, stick to Python.

It can get good with the right setup. I made Codex work with GToolkit (similarly underrepresented, but technically impressive and a seemingly good fit for LLMs), but it took a lot of tweaking of the project structure, extensive instructions in AGENTS.md, and some custom skills (some borrowed from Gt4Llm, the GT's built-in model harness). Out of the box, it burned tokens and took way too long to implement even basic things.

YMMV - as with everything LLM-related - but I think without a similar setup, an agent instructed to write CL/Clj/Scheme/Racket will have the same issues. It might be better in an established, large project - but starting from an empty Git repo, I suspect you'll have to fight your way to productivity.

iLemming27• 14 days ago

Yes, to a certain degree, although it does take initial effort to make it happen.

LLMs do somewhat okay job when you use them with Lisp, treating it just like any other PL, which is roughly the Unix/pipe model - batch-style. Agent spawns process -> reads stdout/stderr -> spawns next process. State lives in-between the calls and in files. Each tool invocation is stateless.

Things get far more interesting when you give an LLM a true Lisp REPL. LLM stops guessing and starts empirically analyzing current state of things and produces working solution faster, costing far less tokens. And you get to watch it solve things interactively, e.g. I often let AI poke through our UI (via Playwright-driven Clojurescript REPL), while monitoring situation in k8s - through nrepl port, connected to Clojure REPL. It literally interactively walks the DOM, finds the selectors, clicks buttons, etc. All without restarts, complex state management and all.

jsphweid• 14 days ago

Why is this being downvoted? It's a reasonable question.

iLemming27• 14 days ago

It is fashionable to misunderstand Lisp and hate AI.

metroholografix• 14 days ago

Current SOTA models work great with Emacs Lisp and Common Lisp. Giving access to the REPL enables them to do an amazing job but they still work well with Unix input/output static code processing paradigm.

frwrfwrfeefwf11• 14 days ago

yes if you run a repl server like slynk the llms will happily communicate with your running program to develop and test things. It's often quite creepy to witness.

mark_l_watson• 13 days ago

I use LLM_based coding agents frequently with Lisp languages and my way of working is different with Lisp languages: 1) if generated code ever has a syntax error, I like to quickly fix the syntax error myself. 2) for some reason I usually prefer to run tests myself in another terminal (with Python, Typescript, etc. I let the coding harness run tests).

I haven’t let coding harnesses run REPLs. When I do let a coding harness run tests I specify in, for examp,e, my Common Lisp skills file to run ‘sbcl -load …” so bash test commands are one liners.

It would be interesting to work on skills and a harness to use REPLs - nothing bad about that idea, I just haven’t tried it.

klibertp4• 14 days ago

So why Lisp (or when)
[...] among its extensibility, its interactive environment, the REPL, and a lot of other features we haven’t touched yet. It is the combination of all of them that makes Lisp programming what it is.

Agreed. However, although the alternatives are few, they do exist. Today, I'd like to convince you (whether you're OP or a commenter) to give one of them a try. I'm talking about GToolkit[1]: Smalltalk/Pharo-based reimagining of Smalltalk as a productive environment for modern system design, analysis, and implementation. It's based on Pharo and its VM, but with GT-specific extensions and replacements, developed on GitHub in both Smalltalk and Rust.

I used both Common Lisp and Smalltalk over the years for some of my side projects. Technically, the environments are comparable: image-based, live, interactive development is central to both. Lisp is easier to fit into modern workflows: it's still just files on disk. If you ignore the REPL and treat the image as a bundler, you can have a Java- or Python-like development workflow. You can gradually adopt the more interactive ways of working with the codebase. Smalltalk was historically more of an "all or nothing" approach, but nowadays it supports Git-based workflows as first-class, with GToolkit providing additional tools directly. GT is tied to a single IDE, but that IDE is genuinely powerful, pragmatic, and easy to customize: the entire IDE is Smalltalk code[2] that lives in the image beside your code, so you can live-edit any part of it at any time.

The languages differ, most obviously in the object model (single inheritance and message sends in Smalltalk, and multiple inheritance with multimethods in CLOS), but I don't think one is strictly better than the other for the vast majority of code. You just need to structure your code differently. Both systems are very dynamic, so neither is like Java or C++. After quite a few projects in both, I am convinced that this difference doesn't matter.

Both languages have very simple syntax. Smalltalk doesn't have macros; instead, it has an extensible/replaceable compiler for method bodies. This capability is used, for example, for compiling grammars into parsers/lexers in SmaCC. It's not as convenient for control-flow abstraction as CL's macros, but Smalltalk tends to make them out of blocks (lexical closures with non-local exits) plus actions on thisContext. In practice, I never found either language too limiting in what I could express, and both have small, regular basic syntax.

TL;DR: Common Lisp and GToolkit Smalltalk offer comparable technical merits, with the most pronounced difference being GT's built-in, high-quality IDE, which open source Lisp lacks.

The IDE (and the capability to build cross-platform, but natively rendered GUI apps) is the major selling point of GToolkit, but the bigger reason to consider it is social. Lisp had a bit of a renaissance from 2005 to 2015, but ~it has since died down~ (EDIT: After checking a bit, it's more like there are similar levels of development now, but it's just varied, and I personally hit a few areas where nothing new happened for a while. Or in other words, the hopes of CL getting catapulted to mainstream by the wave of adoption didn't materialize, and the adoption seems to have largely plateaued, with a slight upward trend since then.) A lot of great things for Lisp appeared in that time: ASDF and Quicklisp being prime examples. Unfortunately, the momentum was lost, and since then, the rate of development has plummeted. It's still a solid proposition because of its stability, which means a lot of old code still works perfectly well, but it's a double-edged sword: it would take a hundred miracles in a row for CL to get a plausible M:N concurrency story, for example. This isn't true for Smalltalk, and doubly so.

There's a small but active community around Pharo, mostly academics and hobbyists (IME; and it's from a decade ago, so YMMV). Pharo itself is already a "Smalltalk-like" language, and it regularly gets features that are not in original Smalltalk (stateful traits and slots (reification of class and instance variables) are good examples). It continues to evolve, and each version brings notable improvements to the language, the VM, and the class library. In CL, since there are many implementations maintained by various groups and the standard is set in stone, adopting extensions to the standard is incredibly hard and time-consuming. You can, of course, commit to a single implementation, but there are only 2 or 3 implementations that are actively developed and trying to do something "new"; they are all experimental and incomplete. And while SBCL has quite a few nice features, its codebase was a bit hard for me to grok (read: days on end of banging my head against a wall, then giving up; I'm much more comfortable messing with Smalltalk bytecode compiler).

Secondly, GToolkit is driven by a group of coders[3] who have established a profitable consultancy. It's being developed around a single vision that the authors swear helps them achieve their projects' goals. Even if you're not sold on moldable development[4] as a methodology, GToolkit gives you all the tools you might need in a modern development and then adds tons of domain-specific tools and utilities that might be useful after just a bit of adjustment. The whole environment is built to make such adjustments as painless as possible, too.

The only problem I experience with GToolkit is the lack of structured, book-like documentation. The GToolkit book is closer to the PHP wiki or a bundle of tutorials than something like the Rust book. It's not that the docs aren't there - they often are, but finding them effectively is a bit challenging. I found that simply cloning all the repos that GT consists of (tens, if not hundreds, but there's automation for that) and pointing an agent to the directory with them is often enough to quickly find what I'm looking for (if the built-in Spotter fails and I'm too lazy to construct an in-image search).

TL;DR: GToolkit/Pharo move much faster than the CL world, and while the number of maintainers might be similar (honestly hard to estimate, though), the effort on the GT side is more centralized and, in my opinion, heads in a better direction. If you want an extensible, live, dynamic environment that shares many of Common Lisp's strengths, but is more polished, more actively maintained, and feels more modern, take a look at GToolkit.

(Disclaimer: no affiliation, just a programmer who likes to explore unpopular languages).

[1] https://gtoolkit.com/

[2] Some parts are implemented as Rust dynamic libraries and called from Smalltalk via FFI.

[3] https://feenk.com/

[4] https://moldabledevelopment.com/

pjmlp5• 13 days ago

All three major programming environments at Xerox PARC, shared similar concepts.

Interlisp-D, Smalltalk, Mesa (XDE) which evolved into Cedar.

If you read Xerox papers about all of them, there are several quotes on how relevant it was to share the same programming experience across environments.

Which is why, given their linage, JVM and CLR are the closest big mindshare ecosystems that somehow still have traces of those features when using their IDEs and runtimes, even without being a proper Smalltalk or Lisp.

klibertp4• 13 days ago

how relevant it was to share the same programming experience across environments.

Right. If you view the language as just a part of a bigger "programming experience", you can do with a worse language with better tooling (pathological example: (lack of) namespaces in many Smalltalks to this day). If you focus on language design above all else, you end up with either something pretty on paper (but never implemented) or something practical and (kind of) elegant, but it'll take 40 years to get the tooling to where you want it (and still won't cover many important capabilities).

Also, it's easier to swap languages if you focus more on tooling. From what I read, many Lisp and Smalltalk IDEs/environments were (and some still are) polyglot. I sadly didn't have access to them at the time, but I imagine switching from Turbo Pascal to Turbo C++ was easier than going from Turbo C++ to Visual C++? That said, tooling tends to break if the language actively fights it, so it's not like PL design is completely irrelevant.

Which is why, given their linage, JVM and CLR are the closest big mindshare ecosystems that somehow still have traces of those features when using their IDEs and runtimes

Yes. The only problem is that those concepts/features become niche black magic (somewhat unavoidable for advanced features in "big mindshare ecosystem"). You can definitely compile Java classes dynamically at runtime, install them, and use them normally; however, outside of frameworks/IDEs/JVM languages, the ClassLoader is used mostly for loading static assets, and even simple reflection is viewed with suspicion.

Using Smalltalk or Lisp directly puts those powerful concepts "front and center", which a) is good for education; and more importantly, b) feels good when things click :) It could be an advantage for small groups of programmers, but from what I understand, it becomes a liability in large organizations. Pharo is especially bad at it, and GToolkit doesn't fix everything (they do a good job at providing tools, but don't want to maintain too large a patch set for Pharo, which is a good trade-off given their limited resources). But I'm replying to "Why Lisp (or When)", and in this context, Smalltalk is (IMO) the better direct alternative than JVM/CLR.

abetusk• 14 days ago

There are many articles extolling the virtues of Lisp. I would like to see some articles that have a level-headed criticisms or critique of Lisp, it's ideas and it's place in the ecosystem of languages.

Articles like this, and the PG articles it references, amount to "if you know, you know". I understand the appeal and I understand the explicit and implicit arguments this article is making.

Computer programming has matured quite a bit in the past 60 years. I would like to see more articles that are more considered in their examination.

erichocean2• 14 days ago

Here you go: https://www.marktarver.com/bipolar.html

It's been discussed many times on HN.

dang3• 14 days ago

and strangely relevant again in the age of LLMs - https://news.ycombinator.com/item?id=48126840

patrec• 14 days ago

https://www.tamaspapp.eu/post/common-lisp-to-julia/

coffeemug• 14 days ago

As a language Lisp is great (though the ecosystem is limited). It has two flaws-- it's very open-ended so unless you're talented and disciplined you can fall into a rabbit hole of hacking fun Lisp stuff and not actually getting any work done. Other languages have this problem, but Lisp I think more so.

The second flaw is that it eats perfectly capable minds for years and the results don't justify the time investment. Python or whatever is fine. I wish I took most (but not all) of the time I invested in Lisp and put it into something else instead.

vkazanov• 13 days ago

Heh, i want to both disagree and agree.

I started with pascal and then C++. And then discovered Emacs and Lisp. Boy, that was a revelation!

Never ever in my life shipped a line of lisp code to production. My real life code was always Python or C++ or Java or C. All of my lisp was toys and emacs tweaks (50k loc in my config!).

But most of production code is gone from my life. I am a mid-level engineering manager now. I mostly write texts, or messages, or emails, or slides... and still use emacs and lisps for fun and profit and competitive programming.

Not a single production-grade lisp LOC in 20+ years. But, OTOH, i contributed to emacs, tinkered with compilers and interpreters and prog. lang. internals - all because Lisps made it interesting for me.

And, in a way, this brought me closer than ever to the job of my dreams: i work for a major player in static analysis space.

So yes, you are right and wrong at the same time.

lenkite2• 14 days ago

I would like to see some articles that have a level-headed criticisms or critique of Lisp, it's ideas and it's place in the ecosystem of languages.

Standardized Concurrency is basic table-stakes for a language today. CL does not have a standardized async/await or concurrency model. The standard hasn't been updated since 1995 so it will never happen.

Jtsummers5• 14 days ago

And it remains in a state of almost getting to the point of generic collections (like C++, Clojure, many others) using the standard functions, but not quite getting there. There are functions (not generic functions) which operate on sequences, but no standard way to extend what types are considered sequences (as one example). It makes sense that the 1995 version of the spec would be incremental, but without a further development (or consensus amongst the implementations if no official standard) it's difficult to continue moving forward to make better use of the language's generic function capabilities.

That's where Clojure, Julia, and many others have advanced beyond what CL (by the standard) provides. The language needed at least one or two more standards to drive those features forward, but never got them.

chamomeal• 14 days ago

CL may not but other lisps do. Clojure’s concurrency is just so hawt

tmtvl• 14 days ago

The standard hasn't been updated since 1995

The latest finalised submission to the Common Lisp Document Repository (confusingly called CDR instead of CLDR) dates from August 4, 2013. CDRs are the equivalent to the SRFIs from the Scheme world. You could argue that they are not THE standard, but they are A standard. And considering the original standardization supposedly cost 400,000 USD (about 900,000 USD in today's money), I can see why there hasn't been another official ANSI standard.

rmunn3• 13 days ago

https://github.com/CodyReichert/awesome-cl lists some concurrency packages, such as https://github.com/sionescu/bordeaux-threads and https://github.com/sharplispers/lparallel, as being "so widespread and solid that they became community standards. You can't be wrong with them." I don't know enough to know whether or not they're right about those being widespread, but if that list is wrong then I'm sure someone will chime in to say so.

So while the official standard may not have concurrency, that does not mean that there isn't a de facto community standard way to do it.

iLemming27• 14 days ago

programming has matured quite a bit

Your wording sounds like it implies that Lisp "got stuck" somewhere in the past, no?

Clojure, Clojurescript, Clojure-Dart, Fennel, Jade, Jank, Jolt, Coalton - these are relatively recent (and still developing) languages, and this is just off the top of my head, there are so many more.

Lisp is not a programming language (in a sense), it's an idea. It influenced pretty much every single PL we use today and continues to do so. You can't really "level-heatedly" criticize an idea, it's like criticizing I dunno, group theory. You can though debate about merits of a specific implementation of it.

throwaway815238• 14 days ago

Your wording sounds like it implies that Lisp "got stuck" somewhere in the past, no?

Pretty much. See pg's famous "Blub Paradox" where he sees Lisp as the top of a tower of lesser languages. He doesn't recognize that Lisp might at best be called a limit ordinal, to use math jargon. That is, Lisp is just another Blub, and the Lisp zealots haven't figured that out.

You don't necessarily want to keep going further and further up, of course. Lisp still has fascination. But e.g., in Common Lisp (I mean just the stuff in the CL spec, no ad-hoc extensions allowed) you can't write anything resembling an OS. You can in Scheme, using continuations to handle process switching.

Going further up, Lisp doesn't make it easy to ensure the absence of particular behaviours in a program, what TAPL calls the purpose of a type system. Tony Morrison has a semi-realistic example of what static types can get you:

http://blog.tmorris.net/posts/understanding-practical-api-de...

Link still works but TLS certificate expired in 2025, tsk tsk.

gf00022• 13 days ago

What idea? S-expressions?

Because that's all these languages share. What's common in CL and Clojure? They are as dissimilar as C and Scala.

throwaway815238• 14 days ago

I mentioned this already but you might like: https://www.cs.kent.ac.uk/people/staff/dat/miranda/wadler87....

vaylian2• 13 days ago

The lisp curse: https://www.winestockwebdesign.com/Essays/Lisp_Curse.html

pjc50• 13 days ago

There seems to be a Lisp .. handedness?

Certain people seem to find it mentally appealing. I would liken it to one of the really niche music genres. Only a small number of people like it, but they do so very intensely. The Stockhausen of programming.

That's basically all it is. A fandom. A remarkably enduring one, but not one which has ever broken out, and therefore is unlikely to ever do so. Now in an even worse position: if you are armed with an LLM and therefore uninterested in the code itself, why on earth would you direct it to write in Lisp?

awolven• 14 days ago

I've been programming Lisp too long to appreciate it's features. It is not until I watch in shock and horror how people sabotage themselves in the popular and economically less risky languages that I suddenly come to appreciate Lisp again.

kensai• 14 days ago

My question always remains. Which variety/implementation of Lisp is it worth it to learn as a hobbyist and which as a professional?

wk_end• 14 days ago

As a professional - assuming you mean “which can I put on my resume to get a job working in that language” - probably (not necessarily!) none, or maybe Clojure.

As a hobbyist, probably all of them. It’s worth at least trying to go through SICP in Scheme (use Racket with the SICP language), it’s worth learning CL (use SBCL) to fully appreciate everything the Lisp world has to offer without compromises, it’s worth learning Clojure because it’s, frankly, a little bit cleaner and more elegant than CL in many respects.

silcoon2• 13 days ago

Next week I will try to answer your question with a new post. Stay tuned!

tehjoker2• 14 days ago

I played a little bit around with LISP but I was astounded when I saw that you run programs using the live REPL. I thought, how can you reliably deploy a finished program if it can get messed with at any time? Why isn't there a way to compile to a binary?

Jtsummers5• 14 days ago

I was astounded when I saw that you run programs using the live REPL.

That's one way, you stopped too early in your investigation though.

You can produce binaries, though the precise mechanism will vary by your implementation. And there's no reason to use the REPL for it. You can create an executable file with something like this:

  (defun main () ...) ; do whatever you need in here for program launch

  (sb-ext:save-lisp-and-die "my-program" :executable t :toplevel #'main)

And then `sbcl --load program.lisp` (or whatever you name it) and it'll produce a binary for you. Other implementations will have other methods of achieving the same thing.

Or, if you don't need a binary, you can have something like this:

  (defun main () ...)

  (main)

And then run `sbcl --load program.lisp`. That will compile and execute it without ever invoking the REPL.

(NB: Using a function named main isn't strictly necessary, I named it that for the example. Name it whatever you want.)

tehjoker2• 13 days ago

Thank you, that's very helpful to know!

greatony• 14 days ago

Just working a very powerful dynamic workflow feature in my agent product. And guess what, LISP is the one I chose for the generated workflow. LoL

phyzix57612• 14 days ago

I'm working on a Lisp dialect which is far from done and changing every day but I thought I would share it: https://github.com/lodenrogue/hith

It uses python for the interpreter.

vaylian2• 13 days ago

Neat. What is the primary use case for this dialect?

phyzix57612• 13 days ago

Its general purpose. For now I'm trying to build out all the basic language features. Once its built I'll use it as my daily driver for whatever I'm coding.

It's a lisp so it can be used for anything since macros have been implemented. You can create your own syntax using macros.

criddell• 14 days ago

I’m guessing there’s some way for a Lisp program to load a DLL and call a function in it so writing a Windows application using the Windows App SDK is likely possible.

The one part I can’t imagine is how do you pass a Lisp function as a callback?

rmunn3• 13 days ago

https://www.quicklisp.org/beta/UNOFFICIAL/docs/cffi/doc/Tuto... has some pointers (which might be harder to understand unless you have read the rest of https://www.quicklisp.org/beta/UNOFFICIAL/docs/cffi/doc/Tuto... first). The short version (which I might be mangling in my attempt to shorten it) is, since Lisp is so very good at creating code, you have your Lisp program create a C function that will be passed as the callback to the API. Then the C function that you created will convert the C data structures to Lisp data structures, and call the Lisp function with those Lisp data structures.

If you're really good at Lisp, you can write that automatic-callback-creation function yourself. But if you're really, really good at Lisp, you will just use one of the ones that other people have already written, e.g. `define-alien-callable` from https://www.sbcl.org/manual/#Calling-Lisp-From-C or some other similar FFI.

pjmlp5• 13 days ago

Yes, Allegro Common Lisp, and Lisp Works support this just fine.

holgerschurig• 13 days ago

It's really fun: I read so many propaganda on Lisp here that by now we should all be coding in it. Don't we get perhaps weekly posts like this?

But ... somehow almost everyone simply ignores this propaganda --- that's actually the way we ought to handle propaganda! Funny that it works with Lisp, but not with many political topics where it can be shown that propaganda really works.

My experience with Lisp is somewhat special-cornered. I only know Emacs-Lisp, and that not great. And for me, Lisp an out, outdated and confusing thing.

I don't know ANY other programming language that elected assembler mnemonics to be "high"-level expression: car and cdr.

While I love Emacs, they claim all the time that is has 100% discovery through build in doc. But that is only 70% true. It doesn't exist in Lisp like it does in other languages. For example, I have an association list. Now, what functions exist that uses them? I can't use the equivalent for (dir alist), alist.dir(), or use some LSP for that. I can't even look in the symbols, because operators are written like assoc or assq with not logic. And then there are either prefixes to them (rassoc) or postfixes (assoc-string).

That there is no namespace is soooo 1970. I mean, even Turbo-Pascal had namespaces.

Typechecking is nonexistant.

At least we have byte-compiling.

And note that I don't croak about the parenthesis. While I find it mildy weird that I as a human program in almost-AST, Emacs has superp support for the parenthesis. So people croaking about them just had never had a good editor IMHO.

Now, one can argue that Emacs Lisp != Common Lisp. But these propaganda articles don't tend to promote one specific Lisp, they only talk in generals. So I can apply this general principle and compare it to the tiny corner of these awful language family.

Panzerschrek2• 13 days ago

Can I write a game using OpenGL in Lisp?

nmdev• 13 days ago

Yes. Kandria [1] is a great example of someone doing exactly this. There's a bunch of information on the development here [2] and the code is open source [3].

[1] https://kandria.com/

[2] https://reader.tymoon.eu/article/413

[3] https://codeberg.org/shirakumo/kandria

Panzerschrek2• 13 days ago

Interesting. I didn't thought it's possible.

peter_retief2• 13 days ago

The real test of a programming language is its readabilty.

I looked at lisp many times and it just doesn't do it for me.

_ph_2• 13 days ago

That might be, on the other side, I consider Lisp highly readable, but quite a few modern languages quite unreadable. For example parsing type signatures with a complex syntax.

Any style of writing you are not familiar with will require a lot of training. Try reading anything written in the Greek alphabet for example.

peter_retief2• 13 days ago

Fair enough.

BeetleB4• 13 days ago

If you've not grown up accustomed to C-style syntax, I assure you that C is less readable. Even a for loop is crazy in C.

vindarel4• 13 days ago

Don't miss out, we had new excellent editors and tools being released in the last months:

Mine: a complete, single-download application that comes with everything needed to experience the interactive and incremental development programming workflow, including hot-reloading and on-the-fly debugging. For CL and Coalton.

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

OLIVE: a new hand-made plugin for VSCode.

ICL: a new REPL for the terminal and the browser with advanced features.

as a bonus: a JupyterLite kernel based on JSCL that runs 100% in the browser.

find them all: https://lispcookbook.github.io/cl-cookbook/editor-support.ht...

rirze2• 13 days ago

I can't find the source for `mine`. Do you have a link?

lioeters• 13 days ago

Looks like Mine is part of Coalton's repo. https://github.com/coalton-lang/coalton/blob/main/mine/READM...

Charon77• 13 days ago

I really love the idea of lisp but feels like the learning curve is steep. Sure you can learn basic lisp in an hour or so but then? You need to learn emacs, all of the plugins, module systems.

Maybe I just don't know where to start.

vindarel4• 13 days ago

Start here with Common Lisp 8-) https://lispcookbook.github.io/cl-cookbook/getting-started.h... To learn the language, look at the good books out there (Touretzky's etc).

ps: you don't need to learn Emacs. A terminal even is enough. See the Cookbook/ Editors section.

davidpapermill• 13 days ago

This is well-written.

I always thought that the "answer" to programming would be that one day everyone would use Lisp and with awesome tooling and libraries things would be wonderful. In fact, my plan for retirement was to build high-quality libraries for a Lisp language to accelerate this process.

Does the rise of AI bring an end to this dream? Is that, once again, we have solved the problem by adding more cruft? Rather than a superintelligent AI writing in the best programming language available, we're going to just spam lots of Python code until it works?

Does this matter? I don't know, I just wanted a world of elegance.

WillAdams2• 13 days ago

I've always wondered what would have happened if the first "Interface Builder"

Jean-Marie Hullot created "SOS Interface" in Lisp for the Macintosh while working at INRIA (1984) which was the first modern "interface builder."

https://denninginstitute.com/itcore/userinterface/GUIHistory...

had become a mainstream Mac product rather than being co-opted for NeXT and use w/ Objective-C.

LISP clicked with me (when taking a comparative language class in college I was the only one who managed to do all of the LISP homework) and learning it was a lot of help in using TeX.

I just wish that there was:

- a nice native or cross-platform GUI toolkit for it which was opensource

- an easy way to distribute projects as stand-alone compiled code

anthk4• 13 days ago

GUI: MCClim, but it's a bit rusty/Motif like/Tk Life.

Deploy: SBCL can build standalone binaries I think.

doug_durham3• 13 days ago

Languages are never the answer. Lisp isn't superior to Visual Basic. They are both Turing complete. Humans can express good ideas in each. It's better to think of languages as tools. An impact drill is not superior to a simple rotary drill. You will have better luck building a deck with an impact drill, but both will do the job.

shevy-java• 13 days ago

After getting comfortable reading code with so many parentheses

I never managed to get over the ().

Ruby has a very flexible syntax, compared to many other languages, in that you can omit syntax in many cases. For instance, using () for method calls is largely, for the most part, optional. So when I have the python code:

    cat = Cat()
    cat.meow()

I find it worse than the ruby code:

    cat = Cat.new
    cat.meow

(Though you can use () in ruby there too; but most people won't do so as there is little point in that.)

This is a superficial issue though. Python's biggest mistake is to require implicit self. It always feels as if I need to hand-hold python and trying to explain to it what an object is and what self is. In ruby I don't have that issue. Note that I find both languages fine, but ruby is "more" object oriented than python is, for many reasons.

Lisp is quite different though. I had some exposure to it via scheme and while it can be fun, I feel that lisp is a worse programming language than either ruby or python. The old game haxima/nazghul was given up eventually, primarily due to lack of time, but also because the author was no longer convinced of scheme (the core of the engine is in C if I recall correctly). He tried to switch to python, though, which did not work (but, again, I think it was mostly due to lack of time). The scheme code in haxima/nazghul was quite interesting (https://sourceforge.net/projects/nazghul/ if you want to look at the scheme code there), but I much prefer either ruby or python there. Although it would be interesting to have DSLs that would really focus on the game or project at hand, like in the old Zak McKracken game.

rirze2• 13 days ago

the ruby code: ``` cat = Cat.new cat.meow ```

As a non-Ruby user, this confuses me. Why can't `Cat.new` be a function reference? Does Ruby explicitly disallow this (i.e. passing around a function)?

wizzwizz4• 13 days ago

You can do this, but there's no syntax. Instead, call the `method` method with `:new` as its argument.

darkinvisible• 13 days ago

I just read the (cool!) article...didn't see a single CAR or CDR --was using them quite a bit... last century!

doug_durham3• 13 days ago

In commercial practice DSLs are an anti-pattern. Someone will create an under-documented DSL that only they understand and move on. The following programmers have to try to decipher this strange language. It is almost always a better idea to use standard language structures and features. Code is read more than it is written.

js83• 13 days ago

Hate to break it to you, but every time you create a function, you're creating your own language, specific to the domain.

I suspect what you're actually objecting to is a lack of referential transparency, which is a problem in many languages (including Lisp, to be fair).

doug_durham3• 12 days ago

I’m not referring to trivial functions nor classes. I talking about things like overloading operators, or changing the default idioms of the language. This means that a person can’t read the code without fully understanding the entire class structure. For the most part DSLs are highly personal. What one person thinks is a great formalism that make it easy to reason about the problem, to everyone else is spaghetti code.

martinflack• 13 days ago

In Lisp, those following programmers can simply macroexpand. With modern tools they can even do it inside their editor, co-located as replacement text in the same source file, connected to a live Lisp environment, if they wish.

A great example is Common Lisp's own LOOP macro - if someone's usage is difficult to understand, you simply ask Lisp to expand it into the more verbose non-LOOP fundamental calls, and you don't need to understand anything about LOOP. In fact you can replace the LOOP form with the expanded code.

That's a key difference from DSL's in most other languages where the DSL code is really data structures that are interpreted.

js83• 13 days ago

Personally, I grew beyond this. I tried Common Lisp, Forth and Haskell. I enjoyed books On Lisp and Let Over Lambda.

Now I think the best programming language is Barry Jay's Triage Calculus, which is close to combinatory logic or untyped lambda calculus.

But unlike lambda calculus (which is easily expressed in TC), triage calculus has a built-in quoting and introspection (similar to Lisp's CAR and CDR), which lets you easily add typechecking. So in TC, you can have any syntax you want, just by building the correct abstraction. It's truly an ultimate programming language.

TC shows that there is a false dichotomy between programming language features and syntax on one hand, and the function/API definitions in the standard library or user code on the other hand. Every time you write a piece of code intended to be reusable, you're adding to the language. It can all be expressed as some term in TC.

All the syntactic squibbles are a matter of habit. Although one syntactic feature you really want in TC is the let over lambda abstraction, because it's somewhat annoying to order combinators by hand.

wild_egg3• 13 days ago

Do you mean Tree Calculus? https://treecalcul.us

js83• 13 days ago

Yes, although I wish he would call it properly triage calculus (see https://treecalcul.us/specification/), because although the languages are almost identical in power, the original tree calculus and triage calculus rules lead to different programs.

sunshine-o• 13 days ago

I am fascinated by lisp but only had the time to mess with clojure for about a year.

My weird take is that lisp would have a better shot if one would replace the parentheses with square brackets. It might just be me but the round parenthesis make it visually painful to look at code blocks. I feel square brackets would fix that.

ballislife30• 13 days ago

Interesting read

A road to Lisp: Why Lisp

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