-- Post-condition: the returned Insts are full zonked
unifyCtxts [] = panic "unifyCtxts []"
unifyCtxts (sig1 : sigs) -- Argument is always non-empty
- = do { mapM unify_ctxt sigs
+ = do { mapM_ unify_ctxt sigs
; theta <- zonkTcThetaType (sig_theta sig1)
; newDictBndrs (sig_loc sig1) theta }
where
checkDistinctTyVars sig_tvs
= do { zonked_tvs <- mapM zonkSigTyVar sig_tvs
- ; foldlM check_dup emptyVarEnv (sig_tvs `zip` zonked_tvs)
+ ; foldlM_ check_dup emptyVarEnv (sig_tvs `zip` zonked_tvs)
; return zonked_tvs }
where
check_dup :: TyVarEnv TcTyVar -> (TcTyVar, TcTyVar) -> TcM (TyVarEnv TcTyVar)