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Comment by nalgeon | Hacker News Reader

If you find the official release notes a bit dry (they really are), I've prepared an interactive version with lots of examples:

- Iterators (range / types / pull / slices / maps).

- Timer changes (garbage collection and reset/stop behavior).

- Canonical values with the `unique` package.

- HTTP cookie handling.

- Copying directories.

- Slices and atomics changes.

https://antonz.org/go-1-23

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Thank you for your service, this is awesome! I'd love to see language maintainers post interactive release notes like this.

I want to understand the purpose of maps.All().

In the example:

  m := map[string]int{"a": 1, "b": 2, "c": 3}
  
  for k, v := range maps.All(m) {
   fmt.Printf("%v:%v ", k, v)
  }
  
  fmt.Println("")
  
  for k, v := range m {
   fmt.Printf("%v:%v ", k, v)
  }

These both output the same thing. What's the point of the addition?

Slices.All() seems similarly redundant and pointless.

Surely I must be misunderstanding something, I hope.

They’re useful because they let you pass a slice or map to something built to handle the new func(func (…) bool) style iterators.

If I create a IterateOver(fn func(func (K, V any) bool)) function, you cannot pass a slice since that doesn’t match fn’s type, but if you wrap it with slices.All it’ll work.

You can use it with other functions that use iterators. For example, here is code that makes a copy of a map keeping only the even keys.

  maps.Collect(xiter.Filter2(func(k, v int) bool { return k%2 == 0 }, maps.All(m)))

This is great, thank you.

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