Teak

A Kotlin-inspired scripting language that runs on Node.js. Write .tk scripts and run them directly, or compile them to JavaScript.

Documentation: teak-lang.aawadia.dev

Install

npm i @teaklang/teak

Or run directly with npx:

npx @teaklang/teak your-script.tk

Quick Start

Write a Teak script:

// hello.tk
println("Hello from Teak!")

val nums = listOf(1, 2, 3, 4, 5)
val doubled = nums.map { it * 2 }
println(doubled)

Run it:

teak hello.tk

Compile it to JavaScript:

teakc hello.tk > hello.js
node hello.js

Language Basics

Variables

val name = "teak"    // immutable
var count = 0        // mutable
count += 1

Functions

fun add(a, b) = a + b

fun greet(name = "Guest") = "Hello, $name!"

println(greet())      // Hello, Guest!
println(greet("Ada")) // Hello, Ada!

Data Classes

data class Point(x, y)

fun (p Point) distanceTo(other) =
  sqrt((p.x - other.x) * (p.x - other.x) +
       (p.y - other.y) * (p.y - other.y))

val a = Point(0, 0)
val b = Point(3, 4)
println(a.distanceTo(b))  // 5

Control Flow

val max = if (a > b) a else b

when (code) {
  200      -> println("OK")
  404      -> println("Not found")
  else     -> println("Unknown")
}

for (i in 1..10) println(i)

var i = 0
while (i < 5) {
  i += 1
}

Collections

val nums = mutableListOf(3, 1, 4, 1, 5)

nums.add(9)
println(nums.sorted())          // [1, 1, 3, 4, 5, 9]
println(nums.filter { it > 3 }) // [4, 5, 9]
println(nums.fold(0) { acc, v -> acc + v })

val counts = listOf("a", "b", "a").groupBy { it }
println(counts)  // {a: [a, a], b: [b]}

HTTP Server

val server = HttpServer(3000)

server.get("/") {
  it.html("<h1>Hello from Teak!</h1>")
}

server.get("/users/:id") {
  val id = it.params.get("id")
  it.json(mutableMapOf("userId" to id))
}

server.post("/users") {
  it.status(201).json(mutableMapOf("created" to it.body.name))
}

server.start()

File Processing

File("server.log").readLines()
  .filter { it.includes("ERROR") }
  .take(20)
  .forEach { println(it) }

Commands

| Command | Description | | ----------------- | ----------------------------------- | | teak <file.tk> | Run a Teak script | | teakc <file.tk> | Compile a Teak script to JavaScript |

Examples

See the examples/ directory for comprehensive, runnable examples of every language feature:

| File | What it covers | | --------------------------- | ------------------------------------------------------------- | | 01-hello-world.tk | The basics — println and comments | | 02-variables-and-types.tk | val/var, immutability, types | | 03-functions.tk | Functions, lambdas, default params, recursion | | 04-control-flow.tk | if/else, when, for-in, while, break, continue | | 05-strings.tk | Interpolation, string methods, triple-quoted strings | | 06-data-classes.tk | Data classes, default fields, receiver functions | | 07-lists.tk | Immutable/mutable lists, functional ops, slicing, sorting | | 08-sets.tk | Sets, set operations (union, intersect, subtract) | | 09-maps.tk | Maps, to operator, functional ops | | 10-sequences.tk | Lazy sequences, pipeline operations | | 11-file-io.tk | File read/write/append/copy/delete, directory ops, JSON | | 12-http-server.tk | HTTP server with routing, middleware, path/query params | | 13-concurrency.tk | go {}, channels, wait groups | | 14-recursion.tk | Recursive algorithms — sum, tree leaves, quicksort, GCD |

Run any example with:

teak examples/03-functions.tk

License

MIT