diff options
Diffstat (limited to 'compiler/utils')
| -rw-r--r-- | compiler/utils/UniqFM.lhs | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/compiler/utils/UniqFM.lhs b/compiler/utils/UniqFM.lhs index 862af99443..d37041c9f2 100644 --- a/compiler/utils/UniqFM.lhs +++ b/compiler/utils/UniqFM.lhs @@ -45,6 +45,7 @@ module UniqFM ( delListFromUFM, plusUFM, plusUFM_C, + plusUFM_CD, minusUFM, intersectUFM, intersectUFM_C, @@ -134,6 +135,16 @@ plusUFM :: UniqFM elt -> UniqFM elt -> UniqFM elt plusUFM_C :: (elt -> elt -> elt) -> UniqFM elt -> UniqFM elt -> UniqFM elt +-- | plusUFM_CD f m1 d1 m2 d2 +-- merges the maps using `f` as the combinding function and d1 resp. d2 as +-- the default value if there is no entry in m1 reps. m2. The domain is the union +-- of the domains of m1 m2. +-- Representative example: +-- > plusUFM_CD f {A: 1, B: 2} 23 {B: 3, C: 4} 42 +-- > == {A: f 1 42, B: f 2 3, C: f 23 4 } +plusUFM_CD :: (elt -> elt -> elt) + -> UniqFM elt -> elt -> UniqFM elt -> elt -> UniqFM elt + minusUFM :: UniqFM elt1 -> UniqFM elt2 -> UniqFM elt1 intersectUFM :: UniqFM elt -> UniqFM elt -> UniqFM elt @@ -222,7 +233,24 @@ delFromUFM_Directly (UFM m) u = UFM (M.delete (getKey u) m) -- M.union is left-biased, plusUFM should be right-biased. plusUFM (UFM x) (UFM y) = UFM (M.union y x) + -- Note (M.union y x), with arguments flipped + -- M.union is left-biased, plusUFM should be right-biased. + plusUFM_C f (UFM x) (UFM y) = UFM (M.unionWith f x y) + +plusUFM_CD f (UFM xm) dx (UFM ym) dy +{- +The following implementation should be used as soon as we can expect +containers-0.5; presumably from GHC 7.9 on: + = UFM $ M.mergeWithKey + (\_ x y -> Just (x `f` y)) + (M.map (\x -> x `f` dy)) + (M.map (\y -> dx `f` y)) + xm ym +-} + = UFM $ M.intersectionWith f xm ym + `M.union` M.map (\x -> x `f` dy) xm + `M.union` M.map (\y -> dx `f` y) ym minusUFM (UFM x) (UFM y) = UFM (M.difference x y) intersectUFM (UFM x) (UFM y) = UFM (M.intersection x y) intersectUFM_C f (UFM x) (UFM y) = UFM (M.intersectionWith f x y) |