I Hope I place d this in the appropriate category, I wanted to point out a confusing description in the in the Verse Glossary for type casting.
It states that :
“You can convert a class to one of its subclasses (called type casting ) by using the syntax NewReference := type_to_cast_to[Reference] , where type_to_cast_to is the type you want to use.”
Although it does state that :
“This is a failable expression because the type conversion will fail if the object can’t be converted to that type — for example, if the class is a different type from the subclass.”
It would be helpful to add a little more detail as to what this means for someone just learning programming and how to use this.
Such as to use down casting with a class the user made themselves it would look something like:
Vehicle := class: "code"
Car:= class(Vehicle):
run():void=
"code"
CarMaker<constructor>():void=Car{}
and to perform the downcast the user would need to make sure they actually initiate the instance of the super class as an instance of the subclass. not just checking if its true. the code will never run otherwise.
Such as:
Hello_world_device:=class(creative_device):
OnBegin<override>()<suspends> : void =
Wrangler : Vehicle =CarMaker() #create a vehicle object of type Car
it is implied to the compiler that car is a vehicle already but the vehicle must be initiated as an instance of a Car object otherwise a Vehicle object could be anything from the compiler’s viewpoint
Now it can be checked if Wrangler of type Vehicle can be downcast into a Car Object and know that it will pass and acess the code within the if statement.
if(NewWrangler :Car= Car[Wrangler]):
NewWrangler.run()
simplifying the code the Wrangler and newWrangler can be combined to remove the unnecessary creation of a new object
Hello_world_device:=class(creative_device):
OnBegin<override>()<suspends> : void =
if(Wrangler := Car[Vehicle[CarMaker()]]):
Wrangler.run()
Doing this certainty has verry few uses where there isn’t any better alternative, but knowing how to do it correctly when you have to use it is good to have in your skillset.