loon is a lisp! https://github.com/ecto/loon

  [type Shape
    [Circle Float]
    [Rect Float Float]]
  
  [fn area [s]
    [match s
      [Circle r]  => [* 3.14 r r]
      [Rect w h]  => [* w h]]]
  
  [area [Circle 5.0]]

• grimgrin

  today at 9:48 PM

  idk how I haven't crossed a lisp with square brackets but dang I am sorta stunned at how I've never even envisioned it? thanks

My little language Newt is 7 kloc. Dunno if it's worth including, it's mostly an exercise to learn how these things work and is not as polished as I'd like.

- Self-hosted

- Compiles to javascript

- Bidirectional typechecking with NbE (based on elaboration zoo)

- Dependent type checking

- type classes

- ADTs with dependent pattern matching

- TCO (trampoline for mutually tail recursive functions)

- Erasure of compile-time only values (0, ω quantities, but not linear)

- Web playground

- LSP (added this month)

- Syntax is similar to Agda / Idris / Haskell

https://github.com/dunhamsteve/newt

Fluent – 4K lines – including parser, interpreter, standard library, IDE, UI, docs, examples. Will grow though.

https://github.com/mlajtos/fluent/blob/main/client.tsx

• surprisetalk

  today at 6:58 PM

  I'll add it! Thanks.

  EDIT: Actually, it's not quite "ML-family" enough for this post. But it is a remarkably cool project! :)

  • solomonb

    today at 8:09 PM

    If you're accepting additions here is a fun one some friends and I did as experiment at the Topos Institute: https://github.com/ToposInstitute/polytt

    And here is a set of single file lambda calculus implementations with a variety of extensions: https://github.com/solomon-b/lambda-calculus-hs

    `polytt` is kind of an ended experiment but that lambda calculus repo i plan to extend in the near future.

Another crazy one is SectorLISP, 223 lines of asm

https://justine.lol/sectorlisp2/

The hardest part with small languages isn't the parser, it's the standard library and error messages. Getting a helpful IDE experience in that footprint is a significant engineering challenge.