SIP public review: Open classes

[eyalroth]

@morgen-peschke

I’m not really sold on open, so I don’t really have any skin in this, but this doesn’t really make sense to me as a counter argument.

Extension methods and typeclasses can only combine the various methods of a class’s external API and can’t be used to override methods, so I don’t think it’s valid to compare them with extending a class or overriding it’s methods.

I’m not sure whether it’s a counter-argument, a comment about the particular wording, or both.

“ad-hoc extensions” is not a term I’m familiar with, but I am familiar with ad-hoc polymorphism, which type classes are a form of.