Pandas like features

[jmh530]

On Saturday, 24 October 2020 at 12:26:21 UTC, 9il wrote:
> [snip]
>
> I would like to say Yes. But the reality is that the answer is 
> that D isn't going to grow. The sci related answer is that the 
> members of DLF either ignore my requests or even reject related 
> work for the compiler because they "don't see much of a 
> difference"
>
> The following work is what really will be good for Sci D and 
> especially for DataFrame.
>
> https://github.com/dlang/DIPs/blob/master/DIPs/other/DIP1023.md
> https://github.com/dlang/dmd/pull/9778

I think, unfortunately, it is not always easy to communicate why 
these changes are important or valuable. But, while you weren't 
able to convince Atila of the value of the proposed features, I 
also don't think you were ignored either, at least in that case.

That being said, I never understood Atila's argument about this 
feature as being a light version of Rust traits (I'm not aware of 
how Haskell's typeclasses work). A Rust trait is a list of 
functions that must be implemented by a type. However, you can 
also statically dispatch based on the trait (you can dynamically 
as well, but I imagine you would prefer not to be able to do 
that). You conceivably would be more interested in the static 
dispatch part of it. It's not really about a 
PackedUpperTriangularMatrix requiring specific functions to be a 
PackedUpperTriangularMatrix rather than a Slice. All it takes is 
the right iterator type. So it's more about how the specific type 
is specialized (giving a specific iterator to 
PackedUpperTriangularMatrix).

There might be a way to create a feature that's not Rust traits 
that does what you want and is a more general feature than this 
type of template alias deduction.