> How comes and they don't allow you to optionally provide types in your function/class signatures so you can help the compiler and speed up the whole process ?

> How comes and they don't allow you to optionally provide types in your function/class signatures so you can help the compiler and speed up the whole process ? How would providing types speed up anything? As far as I can see, the compiler still has to infer types in order to know whether the type you provided is correct.