<html><head><meta http-equiv="Content-Type" content="text/html charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div dir="auto" style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class=""><div style="margin: 0px; line-height: normal; font-family: 'Helvetica Neue'; color: rgb(69, 69, 69);" class="">Hello. I’m trying to make a type family with resolving it inside type checking classes, like CmpNat. Its type signature is «type family Cmp (a :: k1) (b :: k2) :: Ordering», so the function is poly kinded. But it seems unclear how to make its TyCon. I’ve tried to follow the CmpNat and CmpSymbol style, and also saw Any TyCon in TysWiredIn. So this is my attempt:</div><div style="margin: 0px; line-height: normal; font-family: 'Helvetica Neue'; color: rgb(69, 69, 69); min-height: 14px;" class=""><br class=""></div><div style="margin: 0px; line-height: normal; font-family: 'Helvetica Neue'; color: rgb(69, 69, 69);" class="">typeCmpTyCon :: TyCon</div><div style="margin: 0px; line-height: normal; font-family: 'Helvetica Neue'; color: rgb(69, 69, 69);" class="">typeCmpTyCon =</div><div style="margin: 0px; line-height: normal; font-family: 'Helvetica Neue'; color: rgb(69, 69, 69);" class=""> mkFamilyTyCon name</div><div style="margin: 0px; line-height: normal; font-family: 'Helvetica Neue'; color: rgb(69, 69, 69);" class=""> (binders ++ (mkTemplateAnonTyConBinders [ input_kind1, input_kind2 ]))</div><div style="margin: 0px; line-height: normal; font-family: 'Helvetica Neue'; color: rgb(69, 69, 69);" class=""> orderingKind</div><div style="margin: 0px; line-height: normal; font-family: 'Helvetica Neue'; color: rgb(69, 69, 69);" class=""> Nothing</div><div style="margin: 0px; line-height: normal; font-family: 'Helvetica Neue'; color: rgb(69, 69, 69);" class=""> (BuiltInSynFamTyCon ops)</div><div style="margin: 0px; line-height: normal; font-family: 'Helvetica Neue'; color: rgb(69, 69, 69);" class=""> Nothing</div><div style="margin: 0px; line-height: normal; font-family: 'Helvetica Neue'; color: rgb(69, 69, 69);" class=""> NotInjective</div><div style="margin: 0px; line-height: normal; font-family: 'Helvetica Neue'; color: rgb(69, 69, 69);" class=""> where</div><div style="margin: 0px; line-height: normal; font-family: 'Helvetica Neue'; color: rgb(69, 69, 69);" class=""> name = mkWiredInTyConName UserSyntax gHC_TYPELITS (fsLit "Cmp")</div><div style="margin: 0px; line-height: normal; font-family: 'Helvetica Neue'; color: rgb(69, 69, 69);" class=""> typeCmpTyFamNameKey typeCmpTyCon</div><div style="margin: 0px; line-height: normal; font-family: 'Helvetica Neue'; color: rgb(69, 69, 69);" class=""> ops = BuiltInSynFamily</div><div style="margin: 0px; line-height: normal; font-family: 'Helvetica Neue'; color: rgb(69, 69, 69);" class=""> { sfMatchFam = matchFamCmpType</div><div style="margin: 0px; line-height: normal; font-family: 'Helvetica Neue'; color: rgb(69, 69, 69);" class=""> , sfInteractTop = interactTopCmpType</div><div style="margin: 0px; line-height: normal; font-family: 'Helvetica Neue'; color: rgb(69, 69, 69);" class=""> , sfInteractInert = \_ _ _ _ -> []</div><div style="margin: 0px; line-height: normal; font-family: 'Helvetica Neue'; color: rgb(69, 69, 69);" class=""> }</div><div style="margin: 0px; line-height: normal; font-family: 'Helvetica Neue'; color: rgb(69, 69, 69);" class=""> binders@[kv1, kv2] = mkTemplateKindTyConBinders [ liftedTypeKind, liftedTypeKind ]</div><div style="margin: 0px; line-height: normal; font-family: 'Helvetica Neue'; color: rgb(69, 69, 69);" class=""> input_kind1 = mkTyVarTy (binderVar kv1)</div><div style="margin: 0px; line-height: normal; font-family: 'Helvetica Neue'; color: rgb(69, 69, 69);" class=""> input_kind2 = mkTyVarTy (binderVar kv2)</div><div style="margin: 0px; line-height: normal; font-family: 'Helvetica Neue'; color: rgb(69, 69, 69); min-height: 14px;" class=""><br class=""></div><div style="margin: 0px; line-height: normal; font-family: 'Helvetica Neue'; color: rgb(69, 69, 69);" class="">ghci says this:</div><div style="margin: 0px; line-height: normal; font-family: 'Helvetica Neue'; color: rgb(69, 69, 69); min-height: 14px;" class=""><br class=""></div><div style="margin: 0px; line-height: normal; font-family: 'Helvetica Neue'; color: rgb(69, 69, 69);" class="">:kind Cmp </div><div style="margin: 0px; line-height: normal; font-family: 'Helvetica Neue'; color: rgb(69, 69, 69);" class="">Cmp :: forall {k0} {k1}. k0 -> k1 -> Ordering</div><div style="margin: 0px; line-height: normal; font-family: 'Helvetica Neue'; color: rgb(69, 69, 69); min-height: 14px;" class=""><br class=""></div><div style="margin: 0px; line-height: normal; font-family: 'Helvetica Neue'; color: rgb(69, 69, 69);" class="">But then I try to apply it to some values and get this exception:</div><div style="margin: 0px; line-height: normal; font-family: 'Helvetica Neue'; color: rgb(69, 69, 69); min-height: 14px;" class=""><br class=""></div><div style="margin: 0px; line-height: normal; font-family: 'Helvetica Neue'; color: rgb(69, 69, 69);" class="">:kind! Cmp 4 5</div><div style="margin: 0px; line-height: normal; font-family: 'Helvetica Neue'; color: rgb(69, 69, 69); min-height: 14px;" class=""><br class=""></div><div style="margin: 0px; line-height: normal; font-family: 'Helvetica Neue'; color: rgb(69, 69, 69);" class=""><div style="margin: 0px; line-height: normal;" class=""><interactive>:1:15: error:</div><div style="margin: 0px; line-height: normal;" class=""> • Expected kind ‘k0’, but ‘4’ has kind ‘Nat’</div><div style="margin: 0px; line-height: normal;" class=""> • In the first argument of ‘Cmp’, namely ‘4’</div><div style="margin: 0px; line-height: normal;" class=""> In the type ‘Cmp 4 5’</div><div style="margin: 0px; line-height: normal; min-height: 14px;" class=""><br class=""></div><div style="margin: 0px; line-height: normal;" class=""><interactive>:1:17: error:</div><div style="margin: 0px; line-height: normal;" class=""> • Expected kind ‘k1’, but ‘5’ has kind ‘Nat’</div><div style="margin: 0px; line-height: normal;" class=""> • In the second argument of ‘Cmp’, namely ‘5’</div><div style="margin: 0px; line-height: normal;" class=""> In the type ‘Cmp 4 5’</div><div style="margin: 0px; line-height: normal; min-height: 14px;" class=""><br class=""></div><div style="margin: 0px; line-height: normal;" class="">Does anyone know where I made a mistake? Any help would be appreciated.</div></div></div></body></html>