— a lightweight dynamic language for the JVM.

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 Now available: Golo 0-preview6

…and here comes a new Golo preview!

(for the impatient)

Here is what’s new in Golo 0-preview6.

  1. New collection literals for common data structures (arrays, tuples, lists, sets, maps, vectors).
  2. The ability to define structured data types through the struct keyword.
  3. Number literals now support underscores (contributed by Franck Verrot).
  4. Dynamic objects performance is better than ever (~14x factor).

Collection literals

You can now take advantage of collection literals, as summarized in the following table:

Collection Java type Syntax
Tuple gololang.Tuple tuple[1, 2, 3], or simply [1, 2, 3]
Array java.lang.Object[] array[1, 2, 3]
List java.util.LinkedList list[1, 2, 3]
Vector java.util.ArrayList vector[1, 2, 3]
Set java.util.LinkedHashSet set[1, 2, 3]
Map java.util.LinkedHashMap map[[1, "a"], [2, "b"]]

Here is a sample usage:

let data = map[
  ["foo", "bar"],
  ["plop", set[1, 2, 3, 4, 5]],
  ["mrbean", map[
    ["name", "Mr Bean"],
    ["email", "bean@outlook.com"]


Structs are great if you need to define data types:

module sample

struct Person = { name, age, email }

function main = |args| {
  let p1 = Person("Mr Bean", 54, "bean@gmail.com")
  println(p1: name())
  let p2 = Person(): name("John"): age(32): email("john@b-root.com")
  println(p2: age())

Structs come with many goodies, including proper toString(), equals() and hashCode() implementations. They are iterable, and immutable copies can be made.

Because structs translate to real JVM classes, you may also take advantage of augmentations to add behavior, as the following example shows:

module StructDemo

struct Point = { x, y }

augment StructDemo.types.Point {

  function move = |this, offsetX, offsetY| {
    this: x(this: x() + offsetX)
    this: y(this: y() + offsetY)
    return this

function main = |args| {
  let p = Point(1, 1)
  p: move(10, 5)

Dynamic object performance

The runtime method dispatch logic for dynamic objects has been rewritten. The new invokedynamic-based plumbing results in a simpler code with less call site invalidations.

This results in dramatically faster dynamic objects!

In the community

Our small and fun community is active!

Eclipse support

Jeff Maury is making strong progress with the Golo Eclipse tooling, ensuring that it stays current with the additions in the Golo grammar.

AppEngine-based console

Philippe Charrière contributed a few improvements to our demonstration web console that runs on Google AppEngine.

He changed the editor component, providing syntax highlighting. He also included the proper metadata so that the page can be saved as an application on iOS devices. You have no more excuses for not trying Golo while in the bus.

Wanna work on our NetBeans IDE?

The NetBeans support for Golo is currently behind the language evolutions, so if you are interested in helping out this is a very solid bet!

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