{-# LANGUAGE CPP, GeneralizedNewtypeDeriving #-}
{-# OPTIONS_GHC -fno-warn-orphans #-} -- because of Arbitrary (HashMap k v)
-- | Tests for the 'Data.HashMap.Lazy' module. We test functions by
-- comparing them to a simpler model, an association list.
module Main (main) where
import Control.Monad ( guard )
import qualified Data.Foldable as Foldable
#if MIN_VERSION_base(4,10,0)
import Data.Bifoldable
#endif
import Data.Function (on)
import Data.Hashable (Hashable(hashWithSalt))
import qualified Data.List as L
import Data.Ord (comparing)
#if defined(STRICT)
import Data.HashMap.Strict (HashMap)
import qualified Data.HashMap.Strict as HM
import qualified Data.Map.Strict as M
#else
import Data.HashMap.Lazy (HashMap)
import qualified Data.HashMap.Lazy as HM
import qualified Data.Map.Lazy as M
#endif
import Test.QuickCheck (Arbitrary(..), Property, (==>), (===), forAll, elements)
import Test.Framework (Test, defaultMain, testGroup)
import Test.Framework.Providers.QuickCheck2 (testProperty)
import Data.Functor.Identity (Identity (..))
import Control.Applicative (Const (..))
import Test.QuickCheck.Function (Fun, apply)
import Test.QuickCheck.Poly (A, B)
-- Key type that generates more hash collisions.
newtype Key = K { unK :: Int }
deriving (Arbitrary, Eq, Ord, Read, Show)
instance Hashable Key where
hashWithSalt salt k = hashWithSalt salt (unK k) `mod` 20
instance (Eq k, Hashable k, Arbitrary k, Arbitrary v) => Arbitrary (HashMap k v) where
arbitrary = fmap (HM.fromList) arbitrary
------------------------------------------------------------------------
-- * Properties
------------------------------------------------------------------------
-- ** Instances
pEq :: [(Key, Int)] -> [(Key, Int)] -> Bool
pEq xs = (M.fromList xs ==) `eq` (HM.fromList xs ==)
pNeq :: [(Key, Int)] -> [(Key, Int)] -> Bool
pNeq xs = (M.fromList xs /=) `eq` (HM.fromList xs /=)
-- We cannot compare to `Data.Map` as ordering is different.
pOrd1 :: [(Key, Int)] -> Bool
pOrd1 xs = compare x x == EQ
where
x = HM.fromList xs
pOrd2 :: [(Key, Int)] -> [(Key, Int)] -> [(Key, Int)] -> Bool
pOrd2 xs ys zs = case (compare x y, compare y z) of
(EQ, o) -> compare x z == o
(o, EQ) -> compare x z == o
(LT, LT) -> compare x z == LT
(GT, GT) -> compare x z == GT
(LT, GT) -> True -- ys greater than xs and zs.
(GT, LT) -> True
where
x = HM.fromList xs
y = HM.fromList ys
z = HM.fromList zs
pOrd3 :: [(Key, Int)] -> [(Key, Int)] -> Bool
pOrd3 xs ys = case (compare x y, compare y x) of
(EQ, EQ) -> True
(LT, GT) -> True
(GT, LT) -> True
_ -> False
where
x = HM.fromList xs
y = HM.fromList ys
pOrdEq :: [(Key, Int)] -> [(Key, Int)] -> Bool
pOrdEq xs ys = case (compare x y, x == y) of
(EQ, True) -> True
(LT, False) -> True
(GT, False) -> True
_ -> False
where
x = HM.fromList xs
y = HM.fromList ys
pReadShow :: [(Key, Int)] -> Bool
pReadShow xs = M.fromList xs == read (show (M.fromList xs))
pFunctor :: [(Key, Int)] -> Bool
pFunctor = fmap (+ 1) `eq_` fmap (+ 1)
pFoldable :: [(Int, Int)] -> Bool
pFoldable = (L.sort . Foldable.foldr (:) []) `eq`
(L.sort . Foldable.foldr (:) [])
pHashable :: [(Key, Int)] -> [Int] -> Int -> Property
pHashable xs is salt =
x == y ==> hashWithSalt salt x === hashWithSalt salt y
where
xs' = L.nubBy (\(k,_) (k',_) -> k == k') xs
ys = shuffle is xs'
x = HM.fromList xs'
y = HM.fromList ys
-- Shuffle the list using indexes in the second
shuffle :: [Int] -> [a] -> [a]
shuffle idxs = L.map snd
. L.sortBy (comparing fst)
. L.zip (idxs ++ [L.maximum (0:is) + 1 ..])
------------------------------------------------------------------------
-- ** Basic interface
pSize :: [(Key, Int)] -> Bool
pSize = M.size `eq` HM.size
pMember :: Key -> [(Key, Int)] -> Bool
pMember k = M.member k `eq` HM.member k
pLookup :: Key -> [(Key, Int)] -> Bool
pLookup k = M.lookup k `eq` HM.lookup k
pLookupOperator :: Key -> [(Key, Int)] -> Bool
pLookupOperator k = M.lookup k `eq` (HM.!? k)
pInsert :: Key -> Int -> [(Key, Int)] -> Bool
pInsert k v = M.insert k v `eq_` HM.insert k v
pDelete :: Key -> [(Key, Int)] -> Bool
pDelete k = M.delete k `eq_` HM.delete k
newtype AlwaysCollide = AC Int
deriving (Arbitrary, Eq, Ord, Show)
instance Hashable AlwaysCollide where
hashWithSalt _ _ = 1
-- White-box test that tests the case of deleting one of two keys from
-- a map, where the keys' hash values collide.
pDeleteCollision :: AlwaysCollide -> AlwaysCollide -> AlwaysCollide -> Int
-> Property
pDeleteCollision k1 k2 k3 idx = (k1 /= k2) && (k2 /= k3) && (k1 /= k3) ==>
HM.member toKeep $ HM.delete toDelete $
HM.fromList [(k1, 1 :: Int), (k2, 2), (k3, 3)]
where
which = idx `mod` 3
toDelete
| which == 0 = k1
| which == 1 = k2
| which == 2 = k3
| otherwise = error "Impossible"
toKeep
| which == 0 = k2
| which == 1 = k3
| which == 2 = k1
| otherwise = error "Impossible"
pInsertWith :: Key -> [(Key, Int)] -> Bool
pInsertWith k = M.insertWith (+) k 1 `eq_` HM.insertWith (+) k 1
pAdjust :: Key -> [(Key, Int)] -> Bool
pAdjust k = M.adjust succ k `eq_` HM.adjust succ k
pUpdateAdjust :: Key -> [(Key, Int)] -> Bool
pUpdateAdjust k = M.update (Just . succ) k `eq_` HM.update (Just . succ) k
pUpdateDelete :: Key -> [(Key, Int)] -> Bool
pUpdateDelete k = M.update (const Nothing) k `eq_` HM.update (const Nothing) k
pAlterAdjust :: Key -> [(Key, Int)] -> Bool
pAlterAdjust k = M.alter (fmap succ) k `eq_` HM.alter (fmap succ) k
pAlterInsert :: Key -> [(Key, Int)] -> Bool
pAlterInsert k = M.alter (const $ Just 3) k `eq_` HM.alter (const $ Just 3) k
pAlterDelete :: Key -> [(Key, Int)] -> Bool
pAlterDelete k = M.alter (const Nothing) k `eq_` HM.alter (const Nothing) k
-- We choose the list functor here because we don't fuss with
-- it in alterF rules and because it has a sufficiently interesting
-- structure to have a good chance of breaking if something is wrong.
pAlterF :: Key -> Fun (Maybe A) [Maybe A] -> [(Key, A)] -> Property
pAlterF k f xs =
fmap M.toAscList (M.alterF (apply f) k (M.fromList xs))
===
fmap toAscList (HM.alterF (apply f) k (HM.fromList xs))
pAlterFAdjust :: Key -> [(Key, Int)] -> Bool
pAlterFAdjust k =
runIdentity . M.alterF (Identity . fmap succ) k `eq_`
runIdentity . HM.alterF (Identity . fmap succ) k
pAlterFInsert :: Key -> [(Key, Int)] -> Bool
pAlterFInsert k =
runIdentity . M.alterF (const . Identity . Just $ 3) k `eq_`
runIdentity . HM.alterF (const . Identity . Just $ 3) k
pAlterFInsertWith :: Key -> Fun Int Int -> [(Key, Int)] -> Bool
pAlterFInsertWith k f =
runIdentity . M.alterF (Identity . Just . maybe 3 (apply f)) k `eq_`
runIdentity . HM.alterF (Identity . Just . maybe 3 (apply f)) k
pAlterFDelete :: Key -> [(Key, Int)] -> Bool
pAlterFDelete k =
runIdentity . M.alterF (const (Identity Nothing)) k `eq_`
runIdentity . HM.alterF (const (Identity Nothing)) k
pAlterFLookup :: Key
-> Fun (Maybe A) B
-> [(Key, A)] -> Bool
pAlterFLookup k f =
getConst . M.alterF (Const . apply f :: Maybe A -> Const B (Maybe A)) k
`eq`
getConst . HM.alterF (Const . apply f) k
pSubmap :: [(Key, Int)] -> [(Key, Int)] -> Bool
pSubmap xs ys = M.isSubmapOf (M.fromList xs) (M.fromList ys) ==
HM.isSubmapOf (HM.fromList xs) (HM.fromList ys)
pSubmapReflexive :: HashMap Key Int -> Bool
pSubmapReflexive m = HM.isSubmapOf m m
pSubmapUnion :: HashMap Key Int -> HashMap Key Int -> Bool
pSubmapUnion m1 m2 = HM.isSubmapOf m1 (HM.union m1 m2)
pNotSubmapUnion :: HashMap Key Int -> HashMap Key Int -> Property
pNotSubmapUnion m1 m2 = not (HM.isSubmapOf m1 m2) ==> HM.isSubmapOf m1 (HM.union m1 m2)
pSubmapDifference :: HashMap Key Int -> HashMap Key Int -> Bool
pSubmapDifference m1 m2 = HM.isSubmapOf (HM.difference m1 m2) m1
pNotSubmapDifference :: HashMap Key Int -> HashMap Key Int -> Property
pNotSubmapDifference m1 m2 =
not (HM.null (HM.intersection m1 m2)) ==>
not (HM.isSubmapOf m1 (HM.difference m1 m2))
pSubmapDelete :: HashMap Key Int -> Property
pSubmapDelete m = not (HM.null m) ==>
forAll (elements (HM.keys m)) $ \k ->
HM.isSubmapOf (HM.delete k m) m
pNotSubmapDelete :: HashMap Key Int -> Property
pNotSubmapDelete m =
not (HM.null m) ==>
forAll (elements (HM.keys m)) $ \k ->
not (HM.isSubmapOf m (HM.delete k m))
pSubmapInsert :: Key -> Int -> HashMap Key Int -> Property
pSubmapInsert k v m = not (HM.member k m) ==> HM.isSubmapOf m (HM.insert k v m)
pNotSubmapInsert :: Key -> Int -> HashMap Key Int -> Property
pNotSubmapInsert k v m = not (HM.member k m) ==> not (HM.isSubmapOf (HM.insert k v m) m)
------------------------------------------------------------------------
-- ** Combine
pUnion :: [(Key, Int)] -> [(Key, Int)] -> Bool
pUnion xs ys = M.union (M.fromList xs) `eq_` HM.union (HM.fromList xs) $ ys
pUnionWith :: [(Key, Int)] -> [(Key, Int)] -> Bool
pUnionWith xs ys = M.unionWith (-) (M.fromList xs) `eq_`
HM.unionWith (-) (HM.fromList xs) $ ys
pUnionWithKey :: [(Key, Int)] -> [(Key, Int)] -> Bool
pUnionWithKey xs ys = M.unionWithKey go (M.fromList xs) `eq_`
HM.unionWithKey go (HM.fromList xs) $ ys
where
go :: Key -> Int -> Int -> Int
go (K k) i1 i2 = k - i1 + i2
pUnions :: [[(Key, Int)]] -> Bool
pUnions xss = M.toAscList (M.unions (map M.fromList xss)) ==
toAscList (HM.unions (map HM.fromList xss))
------------------------------------------------------------------------
-- ** Transformations
pMap :: [(Key, Int)] -> Bool
pMap = M.map (+ 1) `eq_` HM.map (+ 1)
pTraverse :: [(Key, Int)] -> Bool
pTraverse xs =
L.sort (fmap (L.sort . M.toList) (M.traverseWithKey (\_ v -> [v + 1, v + 2]) (M.fromList (take 10 xs))))
== L.sort (fmap (L.sort . HM.toList) (HM.traverseWithKey (\_ v -> [v + 1, v + 2]) (HM.fromList (take 10 xs))))
pMapKeys :: [(Int, Int)] -> Bool
pMapKeys = M.mapKeys (+1) `eq_` HM.mapKeys (+1)
------------------------------------------------------------------------
-- ** Difference and intersection
pDifference :: [(Key, Int)] -> [(Key, Int)] -> Bool
pDifference xs ys = M.difference (M.fromList xs) `eq_`
HM.difference (HM.fromList xs) $ ys
pDifferenceWith :: [(Key, Int)] -> [(Key, Int)] -> Bool
pDifferenceWith xs ys = M.differenceWith f (M.fromList xs) `eq_`
HM.differenceWith f (HM.fromList xs) $ ys
where
f x y = if x == 0 then Nothing else Just (x - y)
pIntersection :: [(Key, Int)] -> [(Key, Int)] -> Bool
pIntersection xs ys = M.intersection (M.fromList xs) `eq_`
HM.intersection (HM.fromList xs) $ ys
pIntersectionWith :: [(Key, Int)] -> [(Key, Int)] -> Bool
pIntersectionWith xs ys = M.intersectionWith (-) (M.fromList xs) `eq_`
HM.intersectionWith (-) (HM.fromList xs) $ ys
pIntersectionWithKey :: [(Key, Int)] -> [(Key, Int)] -> Bool
pIntersectionWithKey xs ys = M.intersectionWithKey go (M.fromList xs) `eq_`
HM.intersectionWithKey go (HM.fromList xs) $ ys
where
go :: Key -> Int -> Int -> Int
go (K k) i1 i2 = k - i1 - i2
------------------------------------------------------------------------
-- ** Folds
pFoldr :: [(Int, Int)] -> Bool
pFoldr = (L.sort . M.foldr (:) []) `eq` (L.sort . HM.foldr (:) [])
pFoldl :: [(Int, Int)] -> Bool
pFoldl = (L.sort . M.foldl (flip (:)) []) `eq` (L.sort . HM.foldl (flip (:)) [])
#if MIN_VERSION_base(4,10,0)
pBifoldMap :: [(Int, Int)] -> Bool
pBifoldMap xs = concatMap f (HM.toList m) == bifoldMap (:[]) (:[]) m
where f (k, v) = [k, v]
m = HM.fromList xs
pBifoldr :: [(Int, Int)] -> Bool
pBifoldr xs = concatMap f (HM.toList m) == bifoldr (:) (:) [] m
where f (k, v) = [k, v]
m = HM.fromList xs
pBifoldl :: [(Int, Int)] -> Bool
pBifoldl xs = reverse (concatMap f $ HM.toList m) == bifoldl (flip (:)) (flip (:)) [] m
where f (k, v) = [k, v]
m = HM.fromList xs
#endif
pFoldrWithKey :: [(Int, Int)] -> Bool
pFoldrWithKey = (sortByKey . M.foldrWithKey f []) `eq`
(sortByKey . HM.foldrWithKey f [])
where f k v z = (k, v) : z
pFoldMapWithKey :: [(Int, Int)] -> Bool
pFoldMapWithKey = (sortByKey . M.foldMapWithKey f) `eq`
(sortByKey . HM.foldMapWithKey f)
where f k v = [(k, v)]
pFoldrWithKey' :: [(Int, Int)] -> Bool
pFoldrWithKey' = (sortByKey . M.foldrWithKey' f []) `eq`
(sortByKey . HM.foldrWithKey' f [])
where f k v z = (k, v) : z
pFoldlWithKey :: [(Int, Int)] -> Bool
pFoldlWithKey = (sortByKey . M.foldlWithKey f []) `eq`
(sortByKey . HM.foldlWithKey f [])
where f z k v = (k, v) : z
pFoldlWithKey' :: [(Int, Int)] -> Bool
pFoldlWithKey' = (sortByKey . M.foldlWithKey' f []) `eq`
(sortByKey . HM.foldlWithKey' f [])
where f z k v = (k, v) : z
pFoldl' :: [(Int, Int)] -> Bool
pFoldl' = (L.sort . M.foldl' (flip (:)) []) `eq` (L.sort . HM.foldl' (flip (:)) [])
pFoldr' :: [(Int, Int)] -> Bool
pFoldr' = (L.sort . M.foldr' (:) []) `eq` (L.sort . HM.foldr' (:) [])
------------------------------------------------------------------------
-- ** Filter
pMapMaybeWithKey :: [(Key, Int)] -> Bool
pMapMaybeWithKey = M.mapMaybeWithKey f `eq_` HM.mapMaybeWithKey f
where f k v = guard (odd (unK k + v)) >> Just (v + 1)
pMapMaybe :: [(Key, Int)] -> Bool
pMapMaybe = M.mapMaybe f `eq_` HM.mapMaybe f
where f v = guard (odd v) >> Just (v + 1)
pFilter :: [(Key, Int)] -> Bool
pFilter = M.filter odd `eq_` HM.filter odd
pFilterWithKey :: [(Key, Int)] -> Bool
pFilterWithKey = M.filterWithKey p `eq_` HM.filterWithKey p
where p k v = odd (unK k + v)
------------------------------------------------------------------------
-- ** Conversions
-- The free magma is used to test that operations are applied in the
-- same order.
data Magma a
= Leaf a
| Op (Magma a) (Magma a)
deriving (Show, Eq, Ord)
instance Hashable a => Hashable (Magma a) where
hashWithSalt s (Leaf a) = hashWithSalt s (hashWithSalt (1::Int) a)
hashWithSalt s (Op m n) = hashWithSalt s (hashWithSalt (hashWithSalt (2::Int) m) n)
-- 'eq_' already calls fromList.
pFromList :: [(Key, Int)] -> Bool
pFromList = id `eq_` id
pFromListWith :: [(Key, Int)] -> Bool
pFromListWith kvs = (M.toAscList $ M.fromListWith Op kvsM) ==
(toAscList $ HM.fromListWith Op kvsM)
where kvsM = fmap (fmap Leaf) kvs
pFromListWithKey :: [(Key, Int)] -> Bool
pFromListWithKey kvs = (M.toAscList $ M.fromListWithKey combine kvsM) ==
(toAscList $ HM.fromListWithKey combine kvsM)
where kvsM = fmap (\(K k,v) -> (Leaf k, Leaf v)) kvs
combine k v1 v2 = Op k (Op v1 v2)
pToList :: [(Key, Int)] -> Bool
pToList = M.toAscList `eq` toAscList
pElems :: [(Key, Int)] -> Bool
pElems = (L.sort . M.elems) `eq` (L.sort . HM.elems)
pKeys :: [(Key, Int)] -> Bool
pKeys = (L.sort . M.keys) `eq` (L.sort . HM.keys)
------------------------------------------------------------------------
-- * Test list
tests :: [Test]
tests =
[
-- Instances
testGroup "instances"
[ testProperty "==" pEq
, testProperty "/=" pNeq
, testProperty "compare reflexive" pOrd1
, testProperty "compare transitive" pOrd2
, testProperty "compare antisymmetric" pOrd3
, testProperty "Ord => Eq" pOrdEq
, testProperty "Read/Show" pReadShow
, testProperty "Functor" pFunctor
, testProperty "Foldable" pFoldable
, testProperty "Hashable" pHashable
]
-- Basic interface
, testGroup "basic interface"
[ testProperty "size" pSize
, testProperty "member" pMember
, testProperty "lookup" pLookup
, testProperty "!?" pLookupOperator
, testProperty "insert" pInsert
, testProperty "delete" pDelete
, testProperty "deleteCollision" pDeleteCollision
, testProperty "insertWith" pInsertWith
, testProperty "adjust" pAdjust
, testProperty "updateAdjust" pUpdateAdjust
, testProperty "updateDelete" pUpdateDelete
, testProperty "alterAdjust" pAlterAdjust
, testProperty "alterInsert" pAlterInsert
, testProperty "alterDelete" pAlterDelete
, testProperty "alterF" pAlterF
, testProperty "alterFAdjust" pAlterFAdjust
, testProperty "alterFInsert" pAlterFInsert
, testProperty "alterFInsertWith" pAlterFInsertWith
, testProperty "alterFDelete" pAlterFDelete
, testProperty "alterFLookup" pAlterFLookup
, testGroup "isSubmapOf"
[ testProperty "container compatibility" pSubmap
, testProperty "m ⊆ m" pSubmapReflexive
, testProperty "m1 ⊆ m1 ∪ m2" pSubmapUnion
, testProperty "m1 ⊈ m2 ⇒ m1 ∪ m2 ⊈ m1" pNotSubmapUnion
, testProperty "m1\\m2 ⊆ m1" pSubmapDifference
, testProperty "m1 ∩ m2 ≠ ∅ ⇒ m1 ⊈ m1\\m2 " pNotSubmapDifference
, testProperty "delete k m ⊆ m" pSubmapDelete
, testProperty "m ⊈ delete k m " pNotSubmapDelete
, testProperty "k ∉ m ⇒ m ⊆ insert k v m" pSubmapInsert
, testProperty "k ∉ m ⇒ insert k v m ⊈ m" pNotSubmapInsert
]
]
-- Combine
, testProperty "union" pUnion
, testProperty "unionWith" pUnionWith
, testProperty "unionWithKey" pUnionWithKey
, testProperty "unions" pUnions
-- Transformations
, testProperty "map" pMap
, testProperty "traverse" pTraverse
, testProperty "mapKeys" pMapKeys
-- Folds
, testGroup "folds"
[ testProperty "foldr" pFoldr
, testProperty "foldl" pFoldl
#if MIN_VERSION_base(4,10,0)
, testProperty "bifoldMap" pBifoldMap
, testProperty "bifoldr" pBifoldr
, testProperty "bifoldl" pBifoldl
#endif
, testProperty "foldrWithKey" pFoldrWithKey
, testProperty "foldlWithKey" pFoldlWithKey
, testProperty "foldrWithKey'" pFoldrWithKey'
, testProperty "foldlWithKey'" pFoldlWithKey'
, testProperty "foldl'" pFoldl'
, testProperty "foldr'" pFoldr'
, testProperty "foldMapWithKey" pFoldMapWithKey
]
, testGroup "difference and intersection"
[ testProperty "difference" pDifference
, testProperty "differenceWith" pDifferenceWith
, testProperty "intersection" pIntersection
, testProperty "intersectionWith" pIntersectionWith
, testProperty "intersectionWithKey" pIntersectionWithKey
]
-- Filter
, testGroup "filter"
[ testProperty "filter" pFilter
, testProperty "filterWithKey" pFilterWithKey
, testProperty "mapMaybe" pMapMaybe
, testProperty "mapMaybeWithKey" pMapMaybeWithKey
]
-- Conversions
, testGroup "conversions"
[ testProperty "elems" pElems
, testProperty "keys" pKeys
, testProperty "fromList" pFromList
, testProperty "fromListWith" pFromListWith
, testProperty "fromListWithKey" pFromListWithKey
, testProperty "toList" pToList
]
]
------------------------------------------------------------------------
-- * Model
type Model k v = M.Map k v
-- | Check that a function operating on a 'HashMap' is equivalent to
-- one operating on a 'Model'.
eq :: (Eq a, Eq k, Hashable k, Ord k)
=> (Model k v -> a) -- ^ Function that modifies a 'Model'
-> (HM.HashMap k v -> a) -- ^ Function that modified a 'HashMap' in the same
-- way
-> [(k, v)] -- ^ Initial content of the 'HashMap' and 'Model'
-> Bool -- ^ True if the functions are equivalent
eq f g xs = g (HM.fromList xs) == f (M.fromList xs)
infix 4 `eq`
eq_ :: (Eq k, Eq v, Hashable k, Ord k)
=> (Model k v -> Model k v) -- ^ Function that modifies a 'Model'
-> (HM.HashMap k v -> HM.HashMap k v) -- ^ Function that modified a
-- 'HashMap' in the same way
-> [(k, v)] -- ^ Initial content of the 'HashMap'
-- and 'Model'
-> Bool -- ^ True if the functions are
-- equivalent
eq_ f g = (M.toAscList . f) `eq` (toAscList . g)
infix 4 `eq_`
------------------------------------------------------------------------
-- * Test harness
main :: IO ()
main = defaultMain tests
------------------------------------------------------------------------
-- * Helpers
sortByKey :: Ord k => [(k, v)] -> [(k, v)]
sortByKey = L.sortBy (compare `on` fst)
toAscList :: Ord k => HM.HashMap k v -> [(k, v)]
toAscList = L.sortBy (compare `on` fst) . HM.toList