diff options
Diffstat (limited to 'compiler/typecheck/TcSimplify.hs')
| -rw-r--r-- | compiler/typecheck/TcSimplify.hs | 22 |
1 files changed, 11 insertions, 11 deletions
diff --git a/compiler/typecheck/TcSimplify.hs b/compiler/typecheck/TcSimplify.hs index be0735816b..a19ceaa39d 100644 --- a/compiler/typecheck/TcSimplify.hs +++ b/compiler/typecheck/TcSimplify.hs @@ -37,7 +37,7 @@ import TcSMonad as TcS import TcType import TrieMap () -- DV: for now import Type -import TysWiredIn ( liftedDataConTy ) +import TysWiredIn ( ptrRepLiftedTy ) import Unify ( tcMatchTy ) import Util import Var @@ -1488,24 +1488,24 @@ promoteTyVarTcS tclvl tv | otherwise = return () --- | If the tyvar is a levity var, set it to Lifted. Returns whether or +-- | If the tyvar is a RuntimeRep var, set it to PtrRepLifted. Returns whether or -- not this happened. defaultTyVar :: TcTyVar -> TcM () -- Precondition: MetaTyVars only -- See Note [DefaultTyVar] defaultTyVar the_tv - | isLevityVar the_tv - = do { traceTc "defaultTyVar levity" (ppr the_tv) - ; writeMetaTyVar the_tv liftedDataConTy } + | isRuntimeRepVar the_tv + = do { traceTc "defaultTyVar RuntimeRep" (ppr the_tv) + ; writeMetaTyVar the_tv ptrRepLiftedTy } | otherwise = return () -- The common case -- | Like 'defaultTyVar', but in the TcS monad. defaultTyVarTcS :: TcTyVar -> TcS Bool defaultTyVarTcS the_tv - | isLevityVar the_tv - = do { traceTcS "defaultTyVarTcS levity" (ppr the_tv) - ; unifyTyVar the_tv liftedDataConTy + | isRuntimeRepVar the_tv + = do { traceTcS "defaultTyVarTcS RuntimeRep" (ppr the_tv) + ; unifyTyVar the_tv ptrRepLiftedTy ; return True } | otherwise = return False -- the common case @@ -1591,13 +1591,13 @@ There are two caveats: Note [DefaultTyVar] ~~~~~~~~~~~~~~~~~~~ defaultTyVar is used on any un-instantiated meta type variables to -default any levity variables to Lifted. This is important +default any RuntimeRep variables to PtrRepLifted. This is important to ensure that instance declarations match. For example consider instance Show (a->b) foo x = show (\_ -> True) -Then we'll get a constraint (Show (p ->q)) where p has kind ArgKind, +Then we'll get a constraint (Show (p ->q)) where p has kind (TYPE r), and that won't match the typeKind (*) in the instance decl. See tests tc217 and tc175. @@ -1607,7 +1607,7 @@ hand. However we aren't ready to default them fully to () or whatever, because the type-class defaulting rules have yet to run. An alternate implementation would be to emit a derived constraint setting -the levity variable to Lifted, but this seems unnecessarily indirect. +the RuntimeRep variable to PtrRepLifted, but this seems unnecessarily indirect. Note [Promote _and_ default when inferring] ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |