3.5.1. Atom Protocol

Caterpillar provides a special protocol for working with atoms. It is designed to incorporate packing and unpacking of data streams as well as calculating its size and measuring its type.

Changed in version 2.6.0: Reworked the CAPI and its components.

type CpAtomObject

All classes that implement capabilities of an atom should inherit from this class. It defines, but does not implement all four protocol methods. There are no specific members - consider this class to be an abstract base class.

PyTypeObject CpAtom_Type

The type object of the CpAtom class.

TODO: describe missing functions

int CpAtom_HasPack(PyObject *o)

int CpAtom_FastCanPack(PyObject *o, _coremodulestate *state)

Return 1 if the object provides an interface of packing other objects and 0 otherwise. Note that it returns 1 for classes with a __pack__() method, since the type of objects to be packed can not be determined by introspection.

int CpAtom_HasUnpack(PyObject *o)

Return 1 if the object provides an interface of unpacking other objects and 0 otherwise. Note that it returns 1 for classes with a __unpack__() method, since the type of objects to be unpacked can not be determined by introspection.

int CpAtom_HasType(PyObject *o)

Returns 1 if the object provides a method of determining the type this object (usually an atom) represents and 0 otherwise. As all other functions, this one will simply check for the presence of the __type__() method.

int CpAtom_HasSize(PyObject *o)

Searches for __size__(), returns 1 if it is present and 0 otherwise.