2025-04-04 Why does Go's stdlib not have a map function?
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`Since 2022 Go has had generics <https://go.dev/blog/intro-generics>`__, which is great.
(Prior to that, `people perpetrated (ingenious) horrors with the Canadian Aboriginal Syllabics unicode block <https://www.reddit.com/r/rust/comments/5penft/comment/dcsgk7n/>`__)

But three years on, I was really surprised to find no `map function <https://en.wikipedia.org/wiki/Map_(higher-order_function)>`__ in the stdlib.

It's not particularly complex to implement, though I imagine there's a bunch of potential subtleties around optimisation etc.:

.. code:: go

    func Map[FromType, ToType any](slice []FromType, f func(FromType) ToType) []ToType {

        var result = make([]ToType, len(slice))

        for i, v := range slice {
            result[i] = f(v)
        }

        return result
    }

Apparently everyone uses https://github.com/samber/lo ("A Lodash-style Go library").
I can understand wanting to be conservative about what goes in the stdlib,
But ``map`` feels like one of the obvious initial additions to accompany new generics features,
and the absence caught me out!