function_as_args.py

from numba import njit


@njit
def foo(functor, a, b):
    return bar(functor, functor(a, b), b)


@njit
def bar(functor, a, b):
    return functor(a, b)


# First functor
@njit
def add(x, y):
    return x + y

r = foo(add, 1, 2)
print(r)

# Second functor
@njit
def mult(x, y):
    return x * y

r = foo(mult, 1, 2)
print(r)