Singleton

The 'object' keyword in Jackal defines a unique, globally accessible instance. It allows for immediate property assignment and method execution without manual instantiation.

object Person(name) {
    func getName() {
        return this.name
    }
}

Person.name = "jack"
println(Person.getName())

Singletons provide a structured way to maintain global state. Properties assigned to the object are persistent across the application lifecycle.

object Config(version, env) {
    func getDetails() {
        println("Version:", this.version, "Env:", this.env)
    }
}

Config.version = 1.0
Config.env = "production"
Config.getDetails()