This, Super, Descendants and Objects
There are two special symbols that can be used to reference a class member relative to a current position. First,
This is used to resolve ambiguities, if a method contains a parameter and a class member with the same name. The next class contains a method that squares its parameter and adds the equally named class member.
The call to
f shows the intended behavior. Because we do not need the generated object, but for the call, we chain the
Dot operator.
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Members in parent classes can be accessed by means of
Super. The next class inherits from the previously defined
base class and accesses its method
f. Because functionality of a parent class is replaced, we qualify the member with
Override.
Calling this new method shows the desired result
x^3+4*x^2+100.
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Every class registers with its parent. All children of a class may be listed with
Descendants.
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Adding another child class grows the list.
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Super[class] lists the complete chain of inheritance.
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All objects generated by a class may be listed with
Objects[class]. The package itself uses the list only in
RemoveObjects and it can be modified as long as it stays a list.
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Any new object is added to the list. Referenced objects can be listed by
Objects[object]. This list is built on demand.
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There is a test function
ObjectQ to check, if something is an object.
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