diff options
| -rw-r--r-- | compiler/GHC/Types/Unique/DFM.hs | 8 | ||||
| -rw-r--r-- | compiler/GHC/Types/Var/Env.hs | 4 |
2 files changed, 11 insertions, 1 deletions
diff --git a/compiler/GHC/Types/Unique/DFM.hs b/compiler/GHC/Types/Unique/DFM.hs index f3009de2a2..03a4e9bb45 100644 --- a/compiler/GHC/Types/Unique/DFM.hs +++ b/compiler/GHC/Types/Unique/DFM.hs @@ -216,6 +216,8 @@ addListToUDFM_Directly_C f = foldl' (\m (k, v) -> addToUDFM_C_Directly f m k v) delFromUDFM :: Uniquable key => UniqDFM key elt -> key -> UniqDFM key elt delFromUDFM (UDFM m i) k = UDFM (M.delete (getKey $ getUnique k) m) i +-- | Note that this operation is not associative unless the two maps are +-- disjoint. plusUDFM_C :: (elt -> elt -> elt) -> UniqDFM key elt -> UniqDFM key elt -> UniqDFM key elt plusUDFM_C f udfml@(UDFM _ i) udfmr@(UDFM _ j) -- we will use the upper bound on the tag as a proxy for the set size, @@ -256,6 +258,8 @@ plusUDFM_C f udfml@(UDFM _ i) udfmr@(UDFM _ j) -- insertion order and O(m * min(n+m, W)) to insert them into the bigger -- set. +-- | Note that this operation is not associative unless the two maps are +-- disjoint. plusUDFM :: UniqDFM key elt -> UniqDFM key elt -> UniqDFM key elt plusUDFM udfml@(UDFM _ i) udfmr@(UDFM _ j) -- we will use the upper bound on the tag as a proxy for the set size, @@ -413,7 +417,9 @@ allUDFM :: (elt -> Bool) -> UniqDFM key elt -> Bool allUDFM p (UDFM m _i) = M.foldr ((&&) . p . taggedFst) True m instance Semi.Semigroup (UniqDFM key a) where - (<>) = plusUDFM + -- Important to use 'insertUDFMIntoLeft' here as 'plusUDFM' is not + -- associative. + (<>) = insertUDFMIntoLeft instance Monoid (UniqDFM key a) where mempty = emptyUDFM diff --git a/compiler/GHC/Types/Var/Env.hs b/compiler/GHC/Types/Var/Env.hs index ed58c413f4..5376ff3632 100644 --- a/compiler/GHC/Types/Var/Env.hs +++ b/compiler/GHC/Types/Var/Env.hs @@ -594,9 +594,13 @@ filterDVarEnv = filterUDFM alterDVarEnv :: (Maybe a -> Maybe a) -> DVarEnv a -> Var -> DVarEnv a alterDVarEnv = alterUDFM +-- | Note that 'plusDVarEnv' is *not* associative unless the keys of the two +-- maps are disjoint. plusDVarEnv :: DVarEnv a -> DVarEnv a -> DVarEnv a plusDVarEnv = plusUDFM +-- | Note that 'plusDVarEnv_C' is *not* associative unless the keys of the two +-- maps are disjoint. plusDVarEnv_C :: (a -> a -> a) -> DVarEnv a -> DVarEnv a -> DVarEnv a plusDVarEnv_C = plusUDFM_C |