Documentation/history of unapplied method references

I'm curious about unapplied method references. I might have the name wrong, and that's why I can't find very much information (I've found a little nooks and crannies).

I'm interested in any historic facts and references to any documentation or articles.

Example of an unapplied method reference:

let unappliedMethodReference:(String) -> () -> String = String.lowercased

I'm interested because I'm working on a SwiftUI pattern that leverages this. E.g. Text.foregroundColor as an input to a SwiftUI View.

Many thanks for sharing your wisdom.

And a bit more from me, when that was never implemented:


It'd be so nice if we could get uncurried unnaplied references in Swift 6. It probably won't happen, but it'd be great. let mutableFunc = b.someMutableMethod having the type (inout B) -> () -> Void was never a good idea.

Do any of you know the origins of this implementation? Does it have some history in ObjC?