README.md

Dune

Dune combines the simplicity, reliability and efficiency of Go with the flexibility of Typescript.

It is evolving so expect frequent breaking changes.

Try it online, download the latest release or get it from source:

go get github.com/dunelang/dune/cmd/dune

REPL:

Dune v0.95

> 1 + 2
3

Create a hello.ts:

fmt.println("Hello world")

Run it:

$ dune hello.ts 
Hello world

Examples

Arrays have multiple built in functions:

let items = [1, 2, 3, 4, 5]
let r = items.where(t => t > 2).select(t => t * t).sum()
console.log(r)

A web server:

let s = http.newServer()
s.address = ":8080"
s.handler = (w, r) => w.write("Hello world")
s.start() 

Working with databases:

let db = sql.open("sqlite3", ":memory:")
db.exec("CREATE TABLE people (id KEY, name TEXT)")
db.exec("INSERT INTO people (name) VALUES (?)", "Bob")
for (let r of db.query("SELECT id, name FROM people")) {
	console.log(r.id, r.name)
}

Permissions

By default a virtual machine has no access to the external world. The file system is virtual.

This code throws: unauthorized

let p = bytecode.compileStr(`http.get("http://google.com")`)
let vm = runtime.newVM(p)
vm.run()

Programs can request permissions with directives:

// [permissions networking]
http.get("http://google.com") 

Execution limits:

This code throws: Step limit reached: 100

let p = bytecode.compileStr(`while(true) { }`)
let vm = runtime.newVM(p)
vm.maxSteps = 100
vm.run()

This code throws: Max stack frames reached: 5

let p = bytecode.compileStr(`function main() { main() }`)
let vm = runtime.newVM(p)
vm.maxFrames = 5
vm.run()

MaxAllocations counts the number of variables set and in the case of strings their size so it is not very useful yet. This code throws: Max allocations reached: 10

let p = bytecode.compileStr(`
	let v = "*"
	while(true) {
		v += v
	}
`)
let vm = runtime.newVM(p)
vm.maxAllocations = 10
vm.run()

Checkout more examples.

Testing

Since everything is virtual, including the file system, programs are easily testable. There is an assert package in the standard library.

Writing programs

The syntax is a subset of Typescript to get type checking, autocompletion and refactoring tools from editors like VS Code.

$ dune --init
$ code rand.ts

Write a basic program:

export function main(len?: string) {
    let n = convert.toInt(len || "15")
    let v = crypto.randomAlphanumeric(n)
    fmt.println(v)
}   

$ dune rand
1RyXuMFKwmxPbTa6bpXk

To decompile a program:

$ dune -d /tmp/rand.ts 

=============================
Functions
=============================

0F @global
-----------------------------
  0     return              --     --     --   ;   @global


1F main
-----------------------------
  0     MoveAndTest         2L     0L     3L   ;   /tmp/rand.ts:8
  1     TestJump            3L     1D     0D   ;   /tmp/rand.ts:8
  2     Move                2L     0K     --   ;   /tmp/rand.ts:8
  3     CallSingleArg      81N     1L     2L   ;   /tmp/rand.ts:8
  4     CallSingleArg     107N     4L     1L   ;   /tmp/rand.ts:9
  5     CallSingleArg     131N     --     4L   ;   /tmp/rand.ts:10
  6     Return              --     --     --   ;   /tmp/rand.ts:10

  0L len 0-6
  1L n 0-6
  2L @ 0-6
  3L @ 0-6
  4L v 4-6

=============================
Constants
=============================
0K string 15

Embedding

package main

import (
	"fmt"

	"github.com/dunelang/dune"
)

func main() {
	v, err := dune.RunStr("return 3 * 2")
	fmt.Println(v, err)
}

To call Go functions:

package main

import (
	"fmt"
	"log"

	"github.com/dunelang/dune"
)

func main() {
	dune.AddNativeFunc(dune.NativeFunction{
		Name:      "math.square",
		Arguments: 1,
		Function: func(this dune.Value, args []dune.Value, vm *dune.VM) (dune.Value, error) {
			v := args[0].ToInt()
			return dune.NewInt64(v * v), nil
		},
	})

	p, err := dune.CompileStr("return math.square(5)")
	if err != nil {
		log.Fatal(err)
	}

	v, err := dune.NewVM(p).Run()
	if err != nil {
		log.Fatal(err)
	}

	fmt.Println(v)
}

To import the standard library:

package main

import (
	"log"

	"github.com/dunelang/dune"
	_ "github.com/dunelang/dune/lib"
)

func main() {
	_, err := dune.RunStr(`
		let v = { foo: 33 }
		console.log(v)
	`)

	if err != nil {
		log.Fatal(err)
	}
}