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Diffstat (limited to 'compiler/GHC/Types/Unique/FM.hs')
| -rw-r--r-- | compiler/GHC/Types/Unique/FM.hs | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/compiler/GHC/Types/Unique/FM.hs b/compiler/GHC/Types/Unique/FM.hs index 1be4628d8e..265345e2ec 100644 --- a/compiler/GHC/Types/Unique/FM.hs +++ b/compiler/GHC/Types/Unique/FM.hs @@ -59,6 +59,7 @@ module GHC.Types.Unique.FM ( plusUFMList, sequenceUFMList, minusUFM, + minusUFM_C, intersectUFM, intersectUFM_C, disjointUFM, @@ -315,6 +316,14 @@ sequenceUFMList = foldr (plusUFM_CD2 cons) emptyUFM minusUFM :: UniqFM key elt1 -> UniqFM key elt2 -> UniqFM key elt1 minusUFM (UFM x) (UFM y) = UFM (M.difference x y) +-- | @minusUFC_C f map1 map2@ returns @map1@, except that every mapping @key +-- |-> value1@ in @map1@ that shares a key with a mapping @key |-> value2@ in +-- @map2@ is altered by @f@: @value1@ is replaced by @f value1 value2@, where +-- 'Just' means that the new value is used and 'Nothing' means that the mapping +-- is deleted. +minusUFM_C :: (elt1 -> elt2 -> Maybe elt1) -> UniqFM key elt1 -> UniqFM key elt2 -> UniqFM key elt1 +minusUFM_C f (UFM x) (UFM y) = UFM (M.differenceWith f x y) + intersectUFM :: UniqFM key elt1 -> UniqFM key elt2 -> UniqFM key elt1 intersectUFM (UFM x) (UFM y) = UFM (M.intersection x y) |