Where do `@numba.jitclass`ed special methods go?

Question

TL;DR: When decorating a class with @numba.jitclass special methods such as __add__ do not appear in instances of the class, while other methods work normally. Why does this happen?

Consider the following class declaration:

import numba as nb            

dual_spec = [('x', nb.float64), ('y', nb.float64)]                 

@nb.jitclass(dual_spec)
class xy:
    def __init__(self, x, y):
        self.x = x
        self.y = y

    def addition(self, other):
        return xy(self.x + other.x, self.y + other.y)

    def __add__(self, other):
        return xy(self.x + other.x, self.y + other.y)

Without the decorator the class works perfectly fine. Due to the __add__ method expressions like xy(1, 2) + xy(3, 4) are possible and return expected results. However, with the decorator I get the following error message:

>>> xy(1, 2) + xy(3, 4)  # TypeError: unsupported operand type(s) for +: 'xy' and 'xy'
>>> xy(1, 2).addition(xy(3, 4))  # But this works nicely

It looks like the __add__ method is not present in xy objects:

>>> xy(1, 2).__add__  # AttributeError: 'xy' object has no attribute '__add__'

But the method is present in the class:

>>> xy.__add__  #

What is numba doing to the __add__ method during instantiation? Is there another way to enable operators for jitted classes so that I can write xy(1, 2) + xy(3, 4)?

Where do `@numba.jitclass`ed special methods go?

1 Answers