[saagarjha]

"M" is a rather short namespace prefix. Apple recommends using three letter ones: https://developer.apple.com/library/archive/documentation/Co...

[DaiPlusPlus]

It isn’t a namespace, it’s a type-name prefix - Apple has no excuses for not having first-class namespaces in Swift.

[saagarjha]

It's fine for Swift; classes are namespaced by the module they're in. The problem is that it's exposed to Objective-C, and while the runtime class name will differ because it will be mangled, I believe this can still cause source code-level incompatibility with the unmangled names.