"this is not true if.." Well, yes indeed, you can ignore features of a language, but i don't see how it prooves any point. As for the grep, i really have no ide

"this is not true if.." Well, yes indeed, you can ignore features of a language, but i don't see how it prooves any point. As for the grep, i really have no idea what you're talking about ( maybe advanced pattern matching features of advanced language ?). I'm really talking about something very basic, like what swift is doing. My point about interface vs data is that those are two different things, and that i don't think you can't try to solve an issue on type compositions with a feature working on functions only.