New in Go 1.20: wrapping multiple errors

Re:New in Go 1.20: wrapping multiple errors by kasey_junk on Sunday December 11, 2022 @08:50AM (#33943149)

The go language has had generics since inception, just not user defined ones.

If they wanted a set data structure they could have had it like they do maps and slices.

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Re:New in Go 1.20: wrapping multiple errors by XorNot on Sunday December 11, 2022 @09:05AM (#33943263)

Set is just a Map though where you don't care about the values.

var m[string]struct{} implements this for you.

What you're really missing is the usual suite of helper methods which make sets ergonomic - and for that you need proper generics.

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Re:New in Go 1.20: wrapping multiple errors by masklinn on Monday December 12, 2022 @02:47AM (#33952039)

Fwiw lots of folks dislike m[K]struct{}, because while it’s efficient checking for presence is horrible:

    _, present = m[k]

It looks weird and is not an expressions. Obviously you could paper over this with a dedicated builtin function but that’s not great.

A common alternative is m[string]bool, memory density is worse but contains/add/remove are easier to read and more convenient.

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