Constraints on Type Constructors

I’m trying to use Type Constraints on a type constructor in a forall

    data Action = 
      | Dec 
      | MakeEditable (forall a b r1. Lacks a r1 => Cons a b r1 PersonRow => SProxy a) 
      | ChangeCurrent (forall l b r1. IsSymbol l => Lacks l r1 => Cons l b r1 PersonRow => Tuple b (SProxy l)) 

where PersonRow is a Row. When I try to pattern match on ChangeCurrent i get cannot match constrained type. Also when I try to make the type incorrectly. like say (ChangeCurrent (Tuple 1 2)) where 2 isnt even a symbol. i dont get any errors but when i try and when i pattern match i do?

1 Like