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Are you saying something like "All type constructors are functorial Hask^n x Hask^op^m -> Hask"?
by tome 11y ago
Are you saying something like "All type constructors are functorial Hask^n x Hask^op^m -> Hask"?
- catnaroek 11y agoIt's something weaker. Consider the groupoid of Haskell types and isomorphisms. Without GADTs and type families, all type constructors of kind `* -> *` are endofunctors on this groupoid. Note 1: And there are higher-kinded analogues, but I hope you get the idea from this. Note 2: There are also exceptions, like `IORef` and friends.