proposal: slices: Add higher-order functions on slices (map, filter, fold, etc.)

[Aditya-Singhvi]

Proposal Details

I propose adding higher-order functions like Map, Filter, Fold, etc. to the slices library. These higher-order functions make writing data transforms far more ergonomic. They are present in other languages.

I believe this library already implements some version of these: https://pkg.go.dev/github.com/sa-/slicefunk. I think it would be nice for these to be integrated into the standard slices library.

I'm pretty new to Go -- if there's a good language reason for not including these, I'd love to learn more about why!

[randall77]

The plan is to have such functions operate on iterators, not just slices.
See #61898
I'm going to close, as I think that issue subsumes this one. Please reopen if you disagree.

[Aditya-Singhvi]

Cool, thanks! Didn't see that one while I was browsing the issues -- I agree that it definitely subsumes this one.