对多语言用户来说，iOS 键盘切换体验不好。我提出一个设计改进。

The experience of switching keyboards is bad for multilingual users. I propose an enhanced design.

Apple's documentation of CABasicAnimation value interpolation is wrong.

Defaulted arguments are allowed to be reordered.

Any LiteralConvertible can be enumeration raw values.

The big picture of Objective-C invocation forwarding.

Recursive functions are elegant but dangerous to use in Swift.

When override gets involved, overload resolution becomes quite a puzzle.