diff options
Diffstat (limited to 'compiler/types/FamInstEnv.hs')
| -rw-r--r-- | compiler/types/FamInstEnv.hs | 14 |
1 files changed, 7 insertions, 7 deletions
diff --git a/compiler/types/FamInstEnv.hs b/compiler/types/FamInstEnv.hs index c0b6414f8c..168cc0fc40 100644 --- a/compiler/types/FamInstEnv.hs +++ b/compiler/types/FamInstEnv.hs @@ -50,7 +50,6 @@ import CoAxiom import VarSet import VarEnv import Name -import PrelNames ( eqPrimTyConKey ) import UniqDFM import Outputable import Maybes @@ -1253,7 +1252,7 @@ because type families are saturated. But if S has a type family on its RHS we expand /before/ normalising the args t1, t2. If we normalise t1, t2 first, we'll re-normalise them -after expansion, and that can lead to /exponential/ behavour; see #13035. +after expansion, and that can lead to /exponential/ behaviour; see #13035. Notice, though, that expanding first can in principle duplicate t1,t2, which might contain redexes. I'm sure you could conjure up an exponential @@ -1772,9 +1771,8 @@ coreFlattenCo :: TvSubstEnv -> FlattenEnv coreFlattenCo subst env co = (env2, mkCoVarCo covar) where - fresh_name = mkFlattenFreshCoName (env1, kind') = coreFlattenTy subst env (coercionType co) - covar = uniqAway (fe_in_scope env1) (mkCoVar fresh_name kind') + covar = mkFlattenFreshCoVar (fe_in_scope env1) kind' -- Add the covar to the FlattenEnv's in-scope set. -- See Note [Flattening], wrinkle 2A. env2 = updateInScopeSet env1 (flip extendInScopeSet covar) @@ -1827,6 +1825,8 @@ mkFlattenFreshTyName :: Uniquable a => a -> Name mkFlattenFreshTyName unq = mkSysTvName (getUnique unq) (fsLit "flt") -mkFlattenFreshCoName :: Name -mkFlattenFreshCoName - = mkSystemVarName (deriveUnique eqPrimTyConKey 71) (fsLit "flc") +mkFlattenFreshCoVar :: InScopeSet -> Kind -> CoVar +mkFlattenFreshCoVar in_scope kind + = let uniq = unsafeGetFreshLocalUnique in_scope + name = mkSystemVarName uniq (fsLit "flc") + in mkCoVar name kind |