mleku on Nostr: http library has several good examples a simple one that can be part of path routers ...

http library has several good examples

a simple one that can be part of path routers

https://pkg.go.dev/net/http#Client

these closures can themselves be interfaces as this very common example:

https://pkg.go.dev/net/http#Handler

but another version that uses concrete types, and the distinction between them is that the data provided by the closure is - very often, builtin types:

https://pkg.go.dev/path/filepath#WalkFunc