Calling private methods from extensions in separate files

[anon9791410]

@xwu

Swift’s access modifiers are deliberately lexical, not type-based. The access modifier that allows use throughout a module is internal, within a file fileprivate, and within a lexical scope private.

Other languages may offer type-based access modifiers, but that is deliberately not the case for Swift.

This is inaccurate for private, which is a hybrid.

private in Swift actually means fileprotected. I.e. the same as protected, but invisible to other files.

And fileprivate would be better expressed as fileinternal.