- -- If GlasgowExts then check at least one isn't a type variable
- = do checkTc (dopt Opt_TypeSynonymInstances dflags ||
- all tcInstHeadTyNotSynonym tys)
- (instTypeErr (pprClassPred clas tys) head_type_synonym_msg)
- checkTc (dopt Opt_FlexibleInstances dflags ||
- all tcInstHeadTyAppAllTyVars tys)
- (instTypeErr (pprClassPred clas tys) head_type_args_tyvars_msg)
- checkTc (dopt Opt_MultiParamTypeClasses dflags ||
- isSingleton tys)
- (instTypeErr (pprClassPred clas tys) head_one_type_msg)
- mapM_ check_mono_type tys
+ = do { -- If GlasgowExts then check at least one isn't a type variable
+ ; checkTc (dopt Opt_TypeSynonymInstances dflags ||
+ all tcInstHeadTyNotSynonym tys)
+ (instTypeErr (pprClassPred clas tys) head_type_synonym_msg)
+ ; checkTc (dopt Opt_FlexibleInstances dflags ||
+ all tcInstHeadTyAppAllTyVars tys)
+ (instTypeErr (pprClassPred clas tys) head_type_args_tyvars_msg)
+ ; checkTc (dopt Opt_MultiParamTypeClasses dflags ||
+ isSingleton tys)
+ (instTypeErr (pprClassPred clas tys) head_one_type_msg)
+ -- May not contain type family applications
+ ; mapM_ checkTyFamFreeness tys
+
+ ; mapM_ checkValidMonoType tys