Subtyping Rules
Subtype relation C<:D iff there is a chain of subclass relations from D (the super class) to C (the subclass)
How do we modify subtyping rules for
- assignments
- method calls
Assignment
Method calls:
Method definitions:
What is the justification for these changes from the viewpoint of interpreter?
Generic Subtyping Rule:
Uniqueness and Non-Uniqueness of Assigned Types