No support for inheritance?

New To Flow
1

The documentation on Composite Types says that inheritance is not supported. But I read earlier that

AnyStruct is the top type of all non-resource types, i.e., all non-resource types are a subtype of it.

AnyResource is the top type of all resource types.

Would not a “top type” indicate that inheritance was at play? How else does one have an array of AnyStruct objects (structs, rather) unless there was some form of inheritance and super typing?

2

User-defined inheritance isn’t supported, but these are examples of a built-in type hierarchy, which is similar, but not the same as custom inheritance

3

Subtyping and inheritance are two separate concepts: Subtyping defines a hierarchy of types, and inheritance allows the reuse of code / implementations.

In some languages these two concepts are used at the same time, for example in class-based object oriented languages, defining a subclass both inherits from the superclass, and also declares a subtyping relation.

Here is a good explanation: