Actor Attributes & Constants

Actors typically contain some private state. We define variable attributes at the top level in the actor using the var keyword and can then access them from any method within the local actor. Note how self. is not needed. Private variables are not visible from other actors.


actor Act():
    var something = 40  # private actor variable attribute
    fixed = 1234        # public constant
    def hello():
        # We can access local actor variable attributes directly, no need for 
        # self.something or similar
        something += 2
        print("Hello, I'm Act & value of 'something' is: " + str(something))

actor main(env):
    actor1 = Act()
    await async actor1.hello()
    print("Externally visible constant: ", actor1.fixed)
    # This would give an error, try uncommenting it
    # print(actor1.something)


Compile and run:

actonc attrs.act


Hello, I'm Act & value of 'something' is: 42
Externally visible constant:  1234

Without the var keyword, an actor attribute is a constant. As constants are not mutable, it is safe to make it visible to other actors and it can be accessed like an attribute on an object.