Aliases allow types and functions to be given new names and optionally to expose those names from new namespaces.
A type alias is declared with alias type followed by the alias name and any type parameters. This
is assigned to another type. Any constraints on the type parameters come last. It does not create a
separate type only a synonym for an existing type.
public alias type Promise_Result[T] = Promise[Result[T]]
where T <: Example;
Private aliases are useful for creating local shorthands for long types. However, an alias can be
made public or even published to allow it to be used from other places.
When a type alias occurs inside of type declaration, it is an associated member. That is, it is accessed from the type not from any instances.
TODO: is this worth the complexity of adding?
A function alias creates an alias for a function. When declaring a function alias it is not possible to change the parameter types. Thus they are not listed in the alias declaration. However, they are listed when stating the function being aliased in order to disambiguate overloads. An alias does however let one modify generic parameters. Function aliases can be overloaded.
public alias fn example[T] = example[T, T](T, T)
where T <: Example;
TODO: should method aliases be supported as a symmetry with function aliases.