throw
Syntax
throw()
throw(value)
throw(type, value)
throw(subtype, type, value)
Throws an exception that can be caught in a try block (see above). If ran
without arguments, it will throw a user_exception passing null as the value
to the catch_expr. With two arguments you can mimic any other exception type
thrown in scarpet. With 3 arguments, you can specify a custom exception acting
as a subtype of a provided type, allowing to customize try statements with
custom exceptions.