[junke]

The problem is "null" being a value in all (non primitive) types, not only the bottom type. You specify "String", but you can have "null" too. When everything is optional, how do you specify that function foo really takes a String, not null? (https://stackoverflow.com/questions/4963300/which-notnull-ja...)

[mbel]

> The problem is "null" being a value in all (non primitive) types, not only the bottom type.

Null is not a value of bottom type. Bottom type has no values.

[junke]

Thanks, you are right, the bottom type has no value. I meant the "Null" type, which contains a single value, "null".