Kal (Racket)

A Racket implementation of the Kal language, a project by my friend, @maxeonyx.

We wanted to see the performance difference between a quickfire Racket impl and his optimised Rust interpreter.

Benchmarks to come!

---

Usage

$ git clone https://github.com/liamdiprose/kal.rkt.git kal
$ cd kal
$ racket
> (require "main.rkt")

Syntax Comparisons

evens.kal.rkt

(fn (even_numbers)
  (let count 0)
  (loop
    (send yield with count)
    (set! count (+ count 2))))

evens.kal

fn even_numbers() {
  let mut count = 0;
  loop {
    send yield with count;
    count += 2;
  }
}

---

handle.kal.rkt

(handle (even_numbers)
  [(yield num)
   (log num)
   (continue)])

handle.kal

handle even_numbers() {
  yield num {
    log(num);
    continue;
  }
}

---

for.kal.rkt

(for ([num (even_numbers)])
   (log num))

kal.rkt/main.rkt

Lines 95 to 99 in e4fdfe2

	(define-syntax-rule (for ([var gen]) body ...)
	(handle gen
	[(yield var)
	body ...
	(continue)])))

for.kal

for num in even_numbers() {
    log(num);
}

Implementation Status

• Dynamic type system (:free:)
• Explicit mutability
• No Garbage collection
• Object/List spread operators
• Implicit cast to big integers on overflow (:free:)
• Symbols for private fields and langauage-defined behaviour (:free:)

---

• Let bindings (:free:)
• Functions fn (:free:)
• Anonymous functions (only lambda at the moment)
• Addition, multiplication, subtraction, division (:free:)
• Comparision and boolean operators (:free:)
• If expressions (:free:)
• Non-recursive (stack-based)
  • Scheme has tail call optimisation
  • Chez has an efficient implementation of continuations
• Booleans (:free:)
• Integers (:free:)
• Floats (:free:)
• Big Integers (:free:)
• Lists (:free:)
• Objects (:free:)
• Strings (:free:)
• Symbols (:free:)
• Effects
  • send [with <value>]
  • handle
  • break [with <value>]
  • continue [with <value>]
• Explicit effect propagation?
• Forever loops
• For-each loops
• Intrinsics
• Mutable let bindings (:free:)
• Mutable assignment operators
• Mutable object values and list elements (:free:)
• Non-string object keys (:free:)
• Import / export (Racket: require and provide) (:free:)
• Print (:free:)
• Patterns
  • List spread operator
  • List destructuring in let
  • Destructure when receiving function parameters
  • Spread lists into function calls
  • Object spread operator
    • Object destructure in let
  • Nested destructuring in let and function parameters
  • import pattern
  • Renaming in object destructuring
• Proper type-error support (:free:)
• Proper syntax-error support (:free:)
• Integer division operator (:free:)
• Remainder operator (:free:)
• Integer modulo operator (:free:)
• Exponent operator (:free:)
• Numpy-style tensors using ndarray (Racket: math/matrix)
• Floating point numbers (:free:)
• Markdown-like comments
• Doc comments and builtin help function
• CLI binary
• Embeddable Rust library
• JS/WASM runtime
• Native runtime

Wishlist: Granted

• Typed Racket can optimise code based on type proofs, especially used in Racket's math libraries.
• Kal.rkt is syntax agnostic with BNF notation: lang/ast.rkt
• Port Kal.rkt to Kal.gerbil.scm to get an optimised, standalone binary
  • Racket bundles standalone executables using the include_str method @maxeonyx describes
• Compiling to Javascript can be acheived via Gerbil or it's parent, Gambit.