What happens is that every single bit of functionality is split up and abstracted away, so that code duplication is kept at a minimum. Considering that Scala s

What happens is that every single bit of functionality is split up and abstracted away, so that code duplication is kept at a minimum. Considering that Scala ships with BOTH tons of collection types AND tons of useful operations, this seems to be a sane thing to do. Scala manages ... - to make both adding a new operation AND adding a new type not suck too much - to retain the “best” collection type through operations, without duplicating code left and right Most other languages fail already at point number one. No other language has managed to achieve point number two, let alone both.