Passing cython function to cython function

Question

I have a Cython function where I would like to pass in a serialization function as a parameter:

cdef my_serializer(serialization_func, data):
    return serialization_func(data)

All the serializers I'm going to be dealing with (msgpack, ujson) are also C/cython functions. What's the proper way to declare serialization_func so Cython can do early binding?

Answer 1

This works and is reasonably readable:

ctypedef void (*SERIALIZATION_FUNC)(char *data)

cdef void my_serializer(SERIALIZATION_FUNC func, char *data):
    func(data)

Alternately, if you really want to use python objects as parameters and return values

ctypedef object (*SERIALIZATION_FUNC)(object data)

cdef my_serializer(SERIALIZATION_FUNC func, data):
    return func(data)