A modern Lisp that compiles to JavaScript with first class interoperability.

version 0.1.0 ALPHA

Compiler goals

• Interoperability with all Javascript environments (Node, Deno, Bun, browser etc)
• First class REPL (currently against Deno runtime) with realtime syntax highlighting and readline capabilities
• First class compiler error messages

Language features

• First class functions
• Pattern matching
• Destructuring
• Threading
• Macros

Fennel inspired syntax

> (fn fib [n]
    (if (< n 2)
        n
        (+ (fib (- n 1))
           (fib (- n 2)))))

<fn fib>

> (fib 10)

55

Destructuring

> (fn pair->sum [[x y]]
    "Returns the sum of two numbers in a vector."
    (+ x y))

<fn pair->sum>

> (pair->sum [1 4])

5

Pattern matching

> (match [1 2 3]
    []      "empty list"
    [2]     "a single two"
    [_ _]   "two items"
    [1 _ 3] "one something three"
    :else   "unknown")

"one something three"

Macros

> (macro for [[index start end next] body]
    `(do (var ,index ,start)
         (while (!= ,index ,end)
           (do ,body
               (,next ,index)))))

<macro for>

> (for [i 0 10 inc]
    (print (inc 1)))

1 2 3 4 5 6 7 8 9 10

First class interop with any JS runtime

> (-> (. Deno (readTextFileSync "README.md"))
      (split-lines)
      (get 2))

"A modern Lisp that compiles to JavaScript with first class interoperability."

Installation

Requires Go 1.22 and Deno as the compiler uses it as the default environment in which to run compiled code.

Linux

$ make install

Others

$ make build
$ mv rem $(SOME_PATH)

Usage

$ rem -h
Usage: rem [--out OUT] [--repl] [--run] [--debug] [PATH]

Positional arguments:
  PATH                   path to the input file

Options:
  --out OUT, -o OUT      path of the output file
  --repl                 start REPL
  --run                  run the output (deno)
  --debug                print debug info
  --help, -h             display this help and exit