Hyperpolyglot Lisp: Common Lisp, Racket, Clojure, Emacs Lisp

https://hyperpolyglot.org/lisp

by veqq • 2 months ago

214 46 2 months ago

hyperpolyglot.org

eamonnsullivan• 2 months ago

Clojure 1.6, Emacs 24.5... These are pretty old versions, at least of those.

db48x3• 2 months ago

Most of the things in that table won’t change from version to version anyway.

rahen• 2 months ago

Emacs Lisp is a descendant of PDP-10 MAClisp, which makes it one of the oldest Lisp dialects still actively maintained. Whether it's version 24.5 or 30.2 doesn't make much of a difference semantically.

devin• 2 months ago

To be fair I think the only real differences since 1.6 you’d see are transducer versions of some of what’s in here for Clojure. The stuff expressed here is all very basic.

waffletower2• 2 months ago

There is a difference with the very first line item, though minor: "clojure --version" is available. True that transducers aren't going to be a part of this comparison.

waffletower2• 2 months ago

I have been a clojurist for more than a decade and I started with Clojure 1.7. 1.6 was released in 2014!

ecto2• 2 months ago

Great chrestomathy! I opened a PR for my lisp, Loon: https://github.com/clarkgrubb/hyperpolyglot/pull/139

wk_end• 2 months ago

With all due respect, if this page adds a column for everyone's personal Lisp, it'll be as wide as the Pacific.

ecto2• 2 months ago

They say ethics and aesthetics are one!

arikrahman• 2 months ago

Would be interesting to see how Jank is coming along in this space as well.

veqq• 2 months ago

Jank's just supposed to be Clojure with full compatibility, when mature.

sinsudo3• 2 months ago

I know that the purpose of the page is to compare syntax of common lisp, racket, clojure, and emacs lisp. But some examples could be more idiomatic, for instance instead of

  (defun add (a &rest b)
    (if (null b)
        a
        (+ a (eval (cons '+ b)))))

One should avoid eval and use endp instead of null:

   (defun add (a &rest b)
        (if (endp b) a
            (apply #'add (+ a (first b)) (rest b))))

CodeArtisan• 2 months ago

Shouldn't it be (+ a (apply + b))

db48x3• 2 months ago

Almost. It should be (+ a (apply #'+ b)). Common Lisp is a Lisp-2, so a + in the argument position is assumed to be a variable named +, not the function named +, unless you specify otherwise.

gus_massa• 2 months ago

No, the idea is to assume for this example that + only can be used with two arguments and define a new function that can be used with any number of arguments.

ludston4• 2 months ago

Worse: Using recursion in Common Lisp isn't idiomatic, given that CL doesn't guarantee tail-call optimisation in the specification.

dreamcompiler2• 2 months ago

Sigh. This again.

All major Common Lisps support tail call optimization with proper declarations, with the exception of ABCL because it runs on the JVM.

And those declarations are all identical or almost identical, so it's easy to write an implementation-specific macro to guarantee TCO if you need to do so.

Some algorithms are easiest to express and read with looping constructs. For those algorithms, use looping constructs. Other algorithms are easiest to express and read with recursion. For those, use recursion. You shouldn't be afraid of recursion just because ANSI doesn't say TCO is guaranteed. You should be afraid of it if your code needs to run on ABCL, but otherwise, recur on.

aidenn05• 2 months ago

The use of cl:eval alone is enough to make me believe that the CL column was never reviewed by an experienced CL programmer. I am now more suspicious of the other columns, which are languages I'm far less familiar with.

TacticalCoder• 2 months ago

I am now more suspicious of the other columns, which are languages I'm far less familiar with.

It's not bad but for Clojure for example it says "nil is like null in Java" but null in Java is not falsy.

And it also says that destructuring is "named parameters" but it's not so: it's just destructuring (and there are two examples of destructuring given: one for the "named parameters" which aren't named parameters, and one for "parallel assignment" of local variables).

Nothing bad but it's not possible to go into much details in such a table.

kscarlet• 2 months ago

  (defparameter *a* '(1 2 3))
  (setf (car *a*) 3)

And this is undefined behavior because it mutates literal constant. I stopped reading further. The CL column is so bad.

vindarel2• 2 months ago

The trap is using quote, with the list operator there are no issues:

    (defparameter *a* (list 1 2 3))

and of course, mutating top-level variables is bad style.

ethagnawl• 2 months ago

This is really neat.

Something I've been meaning to do is try putting together a cross-lisp package manager -- if only because it'd be fun. Maybe it would favor code that could be readily run or eval'd or maybe with some sort of clj/cljs type dynamic dispatch for anything implementation specific.

sinsudo3• 2 months ago

The page indicates that there is not function for documentation in common lisp, but

  (documentation 'documentation 'function)
      "Return the documentation string of Doc-Type for X, or NIL if none 
        exists. 
        System doc-types are VARIABLE, FUNCTION, STRUCTURE, TYPE, SETF, and T.

 Also http://rosettacode.org for computer tasks implemented in many computer languages to allow you compare syntax and code.

dreamcompiler2• 2 months ago

Likewise apropos. It's an ANSI function.

anthk• 2 months ago

Emacs has cl-lib

https://www.gnu.org/software/emacs/manual/html_mono/cl.html

FrustratedMonky2• 2 months ago

Nice comparison.

But makes me think we'd be better off if we all just focused on a single one, and grew it, made it better. Not having 4 versions of something almost identical. Fragmentation can hurt adoption.

db48x3• 2 months ago

That’s what Common Lisp is.

MathMonkeyMan• 2 months ago

You got downvoted, but you're correct. Obligatory XKCD: <https://xkcd.com/927/>

Personally I prefer lisp 1 languages, like scheme. Even there, though, there was a split over r6rs, so we got a bunch of mostly-like-r5rs schemes and racket.

Maybe the problem is that lisps are no longer popular enough to have a winning implementation! If there is one, though, then it's Common Lisp on SBCL.

erichocean• 2 months ago

There are deep reasons for the variations, especially around (reader) macros.

ludston4• 2 months ago

They are as different from one another as Java is from C# is from JavaScript.

FrustratedMonky2• 2 months ago

So, not by much?

FergusArgyll• 2 months ago

As someone who's not a programmer but has beginner - medium python & C skills. I'm in middle of learning lisp (elisp to be precise) and it feels like reading poetry. It's a transcendent experience that's hard to explain. Such beautiful concepts. Everything flows in a way it doesn't in C based langs

vindarel2• 2 months ago

Notes on CL:

- why nothing on the "compiler" line? Everytime you load a snippet or a file with SBCL, it compiles it (to machine code). There's also compile-file.

- interpreter: likewise, all code is compiled by default with SBCL, not interpreted, even in the REPL. To use the interpreter, we must do this: https://github.com/lisp-tips/lisp-tips/issues/52

- command line program: the racket cell shows the use of -e (eval), the same can be done with any CL implementation.

- since the string split line introduces cl-ppcre, one could mention cl-str :D (plug) (much terser join, trim, concat etc)

- ah ok, for dates and times, flattening a list, hash-table literals… we need more libraries.

- more files operations: https://lispcookbook.github.io/cl-cookbook/files.html

- emacs buffers: now compare with Lem buffers 8-)

- posix-getenv: I'd rather use uiop:getenv (comes in implementations).

- uiop:*command-line-arguments*

- exit: uiop:quit

- uiop:run-program (sync) / launch-program (async)

- java interop: with LispWorks or ABCL (or other libraries)

my 2c

sinsudo3• 2 months ago

Since you are also commenting libraries, I think that FSet (1) for inmutable memory,and perhaps a comparison with clojure, and the quick-lisp package manager could be mentioned.

(1) https://news.ycombinator.com/item?id=47779659

aidenn05• 2 months ago

- ah ok, for dates and times

local-time has its limits (e.g. Gregorian only), but it does everything listed in this chart

flattening a list

What? Isn't this[1] just fine (<s>)

hash-table literals…

Since the chart is sbcl specific, this ugly mess would technically count; a more portable (but longer) version could be made similarly using #.:

  #.(SB-IMPL::%STUFF-HASH-TABLE (MAKE-HASH-TABLE :TEST 'EQUAL) '((:X . :Y)))

> java interop: with LispWorks or ABCL (or other libraries)

I've had good luck with .net/java interop using FOIL (written by Rich Hickey prior to Clojure).

  CL-USER> (let* ((result (cons nil nil))
                 (tail result))
             (subst-if t
                       (constantly nil)
                       '(a ((b(c d)) e) f)
                       :key (lambda (x)
                              (when (and x (atom x)) (setf (cdr tail) (cons x   nil)
                                                           tail (cdr tail)))))
             (cdr result))

=> (A B C D E F)

tmtvl• 2 months ago

Hash-table literals are covered by (among others):

  - Serapeum
  - golden-utils
  - rutils
  - make-hash

Though now I'm wondering which libraries would make for a proper canonical extended core... asdf, uiop (comes with asdf, so naturally), alexandria, bordeaux-threads, cffi, cl-ppcre, str, local-time, trivia,... and maybe fset? (although I personally prefer Sycamore's naming conventions)

...maybe also fivem (although I personally prefer parachute) and hunchentoot.

kickingvegas2• 2 months ago

Perhaps related, I'm maintaining a "cheatsheet" to let Python programmers see what an Elisp equivalent to typical Python functions/methods are.

https://kickingvegas.github.io/elisp-for-python/

emil-lp• 2 months ago

Are `(push s x)` and `(push x s)` correct for push and insert, resp.?

kickingvegas2• 2 months ago

Oh dang, thanks for catching that. Will amend.

aidenn05• 2 months ago

CL list comprehension:

  (loop for file across "ABCDEFGH"
        nconc (loop for rank from 1 to 9
                    collect (format nil "~C~D" file rank)))

Jach• 2 months ago

Or with more Python-esque syntax:

    (let ((files (coerce "ABCDEFGH" 'list))
          (ranks (loop for r from 1 to 9 collect r)))
      [(format nil "~a~a" file rank) (file <- files) (rank <- ranks)])

Based on the list comprehension macro from 1991 in https://3e8.org/pub/scheme/doc/lisp-pointers/v4i2/p16-lapalm... that still works.

    (defmacro comp ((e &rest qs) l2)
      (if (null qs) `(cons ,e ,l2) ; rule A
          (let ((q1 (car qs))
                (q (cdr qs)))
            (if (not (eq (cadr q1) '<-)) ; a generator?
                `(if ,q1 (comp (,e ,@q) ,l2) ,l2) ; rule B
                (let ((v (car q1)) ; rule C
                      (l1 (third q1))
                      (h (gentemp "H-"))
                      (us (gentemp "US-"))
                      (us1 (gentemp "US1-")))
                  `(labels ((,h (,us) ; corresponds to a letrec
                              (if (null ,us) ,l2
                                  (let ((,v (car ,us))
                                        (,us1 (cdr ,us)))
                                    (comp (,e ,@q) (,h ,us1))))))
                     (,h ,l1)))))))

    (defun open-bracket (stream ch)
      (do ((l nil)
           (c (read stream t nil t)(read stream t nil t)))
          ((eq c '|]|) `(comp ,(reverse l) ()))
      (push c l)))

    (defun closing-bracket (stream ch) '|]|)

    (set-macro-character #\[ #'open-bracket)
    (set-macro-character #\] #'closing-bracket)

Supports filtering too, e.g.

    (let ((xs '(1 2 3 4))
          (ys '(1 2 3 4)))
      [(+ x y) (x <- xs) (y <- ys) (evenp x) (oddp y)])
    ; -> (3 5 5 7)

aidenn05• 2 months ago

I didn't try macroexpanding it yet, but when I make the 9 a runtime-parameter, I eventually get a stack-overflow with SBCL not TCO-ing the "H" binding in labels.

The comments make me think this is ported from scheme, which has precise TCO rules.

[edit] macroexpanded:

    (LABELS ((H-37 (US-38)
               (IF (NULL US-38)
                   NIL
                   (LET ((FILE (CAR US-38)) (US1-39 (CDR US-38)))
                     (LABELS ((H-43 (US-44)
                                (IF (NULL US-44)
                                    (H-37 US1-39)
                                    (LET ((RANK (CAR US-44)) (US1-45 (CDR US-44)))
                                      (CONS (FORMAT NIL "~a~a" FILE RANK) (H-43 US1-45))))))
                       (H-43 RANKS))))))
      (H-37 FILES))

dfox• 2 months ago

cannot start with digit

Not only it can, but both CL and Emacs Lisp actually defines primitives with names that start with digit.

Hyperpolyglot Lisp: Common Lisp, Racket, Clojure, Emacs Lisp

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