I forgot something. In a message of Wed, 14 Oct 2015 21:21:30 -0000, Oscar Benjamin writes:
The point of static type checking is to detect precisely these kinds of errors.
Yes, but what I expect the type annotations to be used for, especially in the SciPy world, is to make things easier for Numba to generate fast code. I really hope that the SciPy world is not going to go nuts for useless annotations, but I have, alas, all too many years dealing with people whose desire to have faster code vastly outstrips their ability to understand just what is possible in that regard. In James Barrie's novel, Peter Pan, earthly children are given the ability to fly by having Fairy Dust (supplied by the unwilling Tinkerbell) sprinkled over them. I now know that what a large number of people who want faster code, really want is magic Fairy Dust. They wanted psyco to be it, they wanted pypy to be it, and now they want Numba to be it. The notion that sprinkling type annotations all over their code will make it fly _absolutely deeply resonates_ with how these people wish the world worked. They will believe that type annotations are magic fairy dust until they are forced to confront the fact poorly written code can not be made fly until it is rewritten. Laura