Parametric polymorphism != Hindley-Milner, not even basically. H-M is a construction for describing and ascertaining types of terms in a lambda calculus. Many o

Parametric polymorphism != Hindley-Milner, not even basically. H-M is a construction for describing and ascertaining types of terms in a lambda calculus. Many of those languages don't even typically idiomatically achieve polymorphism through generic types (though of course it's possible), but instead from subtype and ad hoc polymorphism. I don't think it's accurate to imply their designs orbit H-M. I don't want to belabor on technicalities. Your original point was about "table stakes" for type systems in order to be relevant for modern-day software engineering. While I agree a language that attempts to incorporate fashionable computational constructs (like variable binding and lambda terms) ought to derive its type system from something H-M-esque—if only because it's so well understood—it's certainly not a requirement for the language to be taken seriously, and it's certainly not without significant peril in the presence of mutation constructions. I honestly think C, vanilla Common Lisp, and pre-generic Go are sufficiently disparate examples of that.