Design patterns are commons concepts for every devlopper. So I'm trying to implement the basic ones in Golo. The very first one is the Singoloton but I'm facing some issues. 1 - Is it possible to implement it in pure Golo? 2- Without DynamicObjects ? This is my shot. Any thoughts are welcomed!

Singoloton.golo

module g0l0.patterns.creationnal.Singleton

local function _instance = -> null

local function _init = -> DynamicObject():
  testing(|this| -> println(this + "doing some stuff"))

function MyObject = {
  
  if _instance() is null {
    let instance = _init()
	^_instance = -> instance
  }
  
  return _instance()  
}

function main = |args| {

  var instance1 = MyObject()
  var instance2 = MyObject()

  assert (instance1 == instance2)
}

We can't have class / value object definition yet, which means that it is coming at some point. It's a young language after all 😉

It's not a procedure-oriented language, but a kind of functional one, but not really, but duck-typed, and a language always has multiple paradigms, so...

The samples/workers.golo is a good example of scoped objects and dependency injection. It took me a while to realize that scopes and DI are just partial applications on functions...

What about this

module g0l0.patterns.creationnal.Singleton


local function _init = -> DynamicObject():
  testing(|this| -> println(this + " doing some stuff"))

local function _MyObject = |this| -> this

function MySingletonFactory = -> ^_MyObject: bindTo(_init())

function main = |args| {

  let getInstance =  MySingletonFactory()

  let instance1 = getInstance()
  let instance2 = getInstance()

  require(instance1 == instance2, "Must be the same object")

}