A class for class symbols
An exception for cyclic references of symbol definitions
A class for method symbols
A class for module class symbols Note: Not all module classes are of this type; when unpickled, we get plain class symbols!
A class for module symbols
The class for all symbols
A class for term symbols
A class for type parameters viewed from inside their scopes
A class of type symbols.
An object representing a missing symbol
The original owner of a class.