Can you explain what the term 'some' means in the context of programming?

In programming, especially in the Swift language, the keyword some is used to denote opaque types — hidden types that conform to a certain protocol, but the specific type is not revealed. This allows a function or property to return a value that conforms to a protocol without specifying the exact type, increasing flexibility and safety of the code.

For example, a function can return "some" type that implements the View protocol, but without revealing which one:

func makeView() -> some View {
    Text("Hello, world!")
}

Here, some View means that the function returns a specific type that implements the View protocol, but this type is hidden from the calling code. This differs from using protocols with any, where the type can be any that implements the protocol, but the specific type information is lost.