dhall-1.19.1: A configuration language guaranteed to terminate

Safe Haskell | None
Language | Haskell2010

Dhall.Map

Contents

- Type
- Construction
- Sorting
- Insertion
- Deletion/Update
- Query
- Combine
- Traversals
- Conversions

Description

`Map` type used to represent records and unions

Synopsis

- data Map k v
- singleton :: k -> v -> Map k v
- fromList :: Ord k => [(k, v)] -> Map k v
- sort :: Ord k => Map k v -> Map k v
- isSorted :: Eq k => Map k v -> Bool
- insert :: Ord k => k -> v -> Map k v -> Map k v
- insertWith :: Ord k => (v -> v -> v) -> k -> v -> Map k v -> Map k v
- delete :: Ord k => k -> Map k v -> Map k v
- filter :: Ord k => (a -> Bool) -> Map k a -> Map k a
- mapMaybe :: Ord k => (a -> Maybe b) -> Map k a -> Map k b
- lookup :: Ord k => k -> Map k v -> Maybe v
- member :: Ord k => k -> Map k v -> Bool
- uncons :: Ord k => Map k v -> Maybe (k, v, Map k v)
- union :: Ord k => Map k v -> Map k v -> Map k v
- unionWith :: Ord k => (v -> v -> v) -> Map k v -> Map k v -> Map k v
- intersection :: Ord k => Map k a -> Map k b -> Map k a
- intersectionWith :: Ord k => (a -> b -> c) -> Map k a -> Map k b -> Map k c
- difference :: Ord k => Map k a -> Map k b -> Map k a
- mapWithKey :: (k -> a -> b) -> Map k a -> Map k b
- traverseWithKey :: Ord k => Applicative f => (k -> a -> f b) -> Map k a -> f (Map k b)
- traverseWithKey_ :: Ord k => Applicative f => (k -> a -> f ()) -> Map k a -> f ()
- foldMapWithKey :: (Monoid m, Ord k) => (k -> a -> m) -> Map k a -> m
- toList :: Ord k => Map k v -> [(k, v)]
- toMap :: Map k v -> Map k v
- keys :: Map k v -> [k]

# Type

data Map k v Source #

A `Map` that remembers the original ordering of keys

This is primarily used so that formatting preserves field order

This is done primarily to avoid a dependency on `insert-ordered-containers` and also to improve performance

Instances

Functor (Map k) Source # |
Instance details Defined in Dhall.Map Methods fmap :: (a -> b) -> Map k a -> Map k b Source # (<$) :: a -> Map k b -> Map k a Source #
Foldable (Map k) Source # |

Instance details

Defined in Dhall.Map

Methods

fold :: Monoid m => Map k m -> m Source #

foldMap :: Monoid m => (a -> m) -> Map k a -> m Source #

foldr :: (a -> b -> b) -> b -> Map k a -> b Source #

foldr' :: (a -> b -> b) -> b -> Map k a -> b Source #

foldl :: (b -> a -> b) -> b -> Map k a -> b Source #

foldl' :: (b -> a -> b) -> b -> Map k a -> b Source #

foldr1 :: (a -> a -> a) -> Map k a -> a Source #

foldl1 :: (a -> a -> a) -> Map k a -> a Source #

toList :: Map k a -> [a] Source #

null :: Map k a -> Bool Source #

length :: Map k a -> Int Source #

elem :: Eq a => a -> Map k a -> Bool Source #

maximum :: Ord a => Map k a -> a Source #

minimum :: Ord a => Map k a -> a Source #

sum :: Num a => Map k a -> a Source #

product :: Num a => Map k a -> a Source #

Traversable (Map k) Source # |
Instance details Defined in Dhall.Map Methods traverse :: Applicative f => (a -> f b) -> Map k a -> f (Map k b) Source # sequenceA :: Applicative f => Map k (f a) -> f (Map k a) Source # mapM :: Monad m => (a -> m b) -> Map k a -> m (Map k b) Source # sequence :: Monad m => Map k (m a) -> m (Map k a) Source #
Ord k => IsList (Map k v) Source # |
Instance details Defined in Dhall.Map Associated Types type Item (Map k v) :: Type Source # Methods fromList :: [Item (Map k v)] -> Map k v Source # fromListN :: Int -> [Item (Map k v)] -> Map k v Source # toList :: Map k v -> [Item (Map k v)] Source #
(Eq k, Eq v) => Eq (Map k v) Source # |
Instance details Defined in Dhall.Map Methods (==) :: Map k v -> Map k v -> Bool Source # (/=) :: Map k v -> Map k v -> Bool Source #
(Data k, Data v, Ord k) => Data (Map k v) Source # |

Instance details

Defined in Dhall.Map

Methods

gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> Map k v -> c (Map k v) Source #

gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c (Map k v) Source #

toConstr :: Map k v -> Constr Source #

dataTypeOf :: Map k v -> DataType Source #

dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c (Map k v)) Source #

dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c (Map k v)) Source #

gmapT :: (forall b. Data b => b -> b) -> Map k v -> Map k v Source #

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> Map k v -> r Source #

gmapQr :: (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> Map k v -> r Source #

gmapQ :: (forall d. Data d => d -> u) -> Map k v -> [u] Source #

gmapQi :: Int -> (forall d. Data d => d -> u) -> Map k v -> u Source #

gmapM :: Monad m => (forall d. Data d => d -> m d) -> Map k v -> m (Map k v) Source #

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> Map k v -> m (Map k v) Source #

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> Map k v -> m (Map k v) Source #

(Show k, Show v, Ord k) => Show (Map k v) Source # |
Instance details Defined in Dhall.Map Methods showsPrec :: Int -> Map k v -> ShowS Source # show :: Map k v -> String Source # showList :: [Map k v] -> ShowS Source #
Ord k => Semigroup (Map k v) Source # |
Instance details Defined in Dhall.Map Methods (<>) :: Map k v -> Map k v -> Map k v Source # sconcat :: NonEmpty (Map k v) -> Map k v Source # stimes :: Integral b => b -> Map k v -> Map k v Source #
Ord k => Monoid (Map k v) Source # |
Instance details Defined in Dhall.Map Methods mempty :: Map k v Source # mappend :: Map k v -> Map k v -> Map k v Source # mconcat :: [Map k v] -> Map k v Source #
type Item (Map k v) Source # |
Instance details Defined in Dhall.Map type Item (Map k v) = (k, v)

# Construction

singleton :: k -> v -> Map k v Source #

Create a `Map` from a single key-value pair

    >>> singleton "A" 1
    fromList [("A",1)]

fromList :: Ord k => [(k, v)] -> Map k v Source #

Create a `Map` from a list of key-value pairs

    fromList empty = mempty

    fromList (x <|> y) = fromList x <> fromList y

    >>> fromList [("B",1),("A",2)]  -- The map preserves order
    fromList [("B",1),("A",2)]
    >>> fromList [("A",1),("A",2)]  -- For duplicates, later values take precedence
    fromList [("A",2)]

# Sorting

sort :: Ord k => Map k v -> Map k v Source #

Sort the keys of a `Map`, forgetting the original ordering

    sort (sort x) = sort x

    >>> sort (fromList [("B",1),("A",2)])
    fromList [("A",2),("B",1)]

isSorted :: Eq k => Map k v -> Bool Source #

Check if the keys of a `Map` are already sorted

    isSorted (sort m) = True

    >>> isSorted (fromList [("B",1),("A",2)])  -- Sortedness is based only on keys
    False
    >>> isSorted (fromList [("A",2),("B",1)])
    True

# Insertion

insert :: Ord k => k -> v -> Map k v -> Map k v Source #

Insert a key-value pair into a `Map`, overriding any previous value stored underneath the same key, if present

    insert = insertWith (\v _ -> v)

    >>> insert "C" 1 (fromList [("B",2),("A",3)])  -- Values are inserted on left
    fromList [("C",1),("B",2),("A",3)]
    >>> insert "C" 1 (fromList [("C",2),("A",3)])  -- New value takes precedence
    fromList [("C",1),("A",3)]

insertWith :: Ord k => (v -> v -> v) -> k -> v -> Map k v -> Map k v Source #

Insert a key-value pair into a `Map`, using the supplied function to combine the new value with any old value underneath the same key, if present

    >>> insertWith (+) "C" 1 (fromList [("B",2),("A",3)])  -- No collision
    fromList [("C",1),("B",2),("A",3)]
    >>> insertWith (+) "C" 1 (fromList [("C",2),("A",3)])  -- Collision
    fromList [("C",3),("A",3)]

# Deletion/Update

delete :: Ord k => k -> Map k v -> Map k v Source #

Delete a key from a `Map` if present, otherwise return the original `Map`

    >>> delete "B" (fromList [("C",1),("B",2),("A",3)])
    fromList [("C",1),("A",3)]
    >>> delete "D" (fromList [("C",1),("B",2),("A",3)])
    fromList [("C",1),("B",2),("A",3)]

filter :: Ord k => (a -> Bool) -> Map k a -> Map k a Source #

Keep all values that satisfy the given predicate

    >>> filter even (fromList [("C",3),("B",2),("A",1)])
    fromList [("B",2)]
    >>> filter odd (fromList [("C",3),("B",2),("A",1)])
    fromList [("C",3),("A",1)]

mapMaybe :: Ord k => (a -> Maybe b) -> Map k a -> Map k b Source #

Transform all values in a `Map` using the supplied function, deleting the key if the function returns `Nothing`

    >>> mapMaybe Data.Maybe.listToMaybe (fromList [("C",[1]),("B",[]),("A",[3])])
    fromList [("C",1),("A",3)]

# Query

lookup :: Ord k => k -> Map k v -> Maybe v Source #

Retrieve a key from a `Map`

    lookup k mempty = empty

    lookup k (x <> y) = lookup k y <|> lookup k x

    >>> lookup "A" (fromList [("B",1),("A",2)])
    Just 2
    >>> lookup "C" (fromList [("B",1),("A",2)])
    Nothing

member :: Ord k => k -> Map k v -> Bool Source #

Check if a key belongs to a `Map`

    member k mempty = False

    member k (x <> y) = member k x || member k y

    >>> member "A" (fromList [("B",1),("A",2)])
    True
    >>> member "C" (fromList [("B",1),("A",2)])
    False

uncons :: Ord k => Map k v -> Maybe (k, v, Map k v) Source #

Retrieve the first key, value of the `Map`, if present, and also returning the rest of the `Map`.

    uncons mempty = empty

    uncons (singleton k v) = (k, v, mempty)

    >>> uncons (fromList [("C",1),("B",2),("A",3)])
    Just ("C",1,fromList [("B",2),("A",3)])
    >>> uncons (fromList [])
    Nothing

# Combine

union :: Ord k => Map k v -> Map k v -> Map k v Source #

Combine two `Map`s, preferring keys from the first `Map`

    union = unionWith (\v _ -> v)

    >>> union (fromList [("D",1),("C",2)]) (fromList [("B",3),("A",4)])
    fromList [("D",1),("C",2),("B",3),("A",4)]
    >>> union (fromList [("D",1),("C",2)]) (fromList [("C",3),("A",4)])
    fromList [("D",1),("C",2),("A",4)]

unionWith :: Ord k => (v -> v -> v) -> Map k v -> Map k v -> Map k v Source #

Combine two `Map`s using a combining function for colliding keys

    >>> unionWith (+) (fromList [("D",1),("C",2)]) (fromList [("B",3),("A",4)])
    fromList [("D",1),("C",2),("B",3),("A",4)]
    >>> unionWith (+) (fromList [("D",1),("C",2)]) (fromList [("C",3),("A",4)])
    fromList [("D",1),("C",5),("A",4)]

intersection :: Ord k => Map k a -> Map k b -> Map k a Source #

Combine two `Map` on their shared keys, keeping the value from the first `Map`

    intersection = intersectionWith (\v _ -> v)

    >>> intersection (fromList [("C",1),("B",2)]) (fromList [("B",3),("A",4)])
    fromList [("B",2)]

intersectionWith :: Ord k => (a -> b -> c) -> Map k a -> Map k b -> Map k c Source #

Combine two `Map`s on their shared keys, using the supplied function to combine values from the first and second `Map`

    >>> intersectionWith (+) (fromList [("C",1),("B",2)]) (fromList [("B",3),("A",4)])
    fromList [("B",5)]

difference :: Ord k => Map k a -> Map k b -> Map k a Source #

Compute the difference of two `Map`s by subtracting all keys from the second `Map` from the first `Map`

    >>> difference (fromList [("C",1),("B",2)]) (fromList [("B",3),("A",4)])
    fromList [("C",1)]

# Traversals

mapWithKey :: (k -> a -> b) -> Map k a -> Map k b Source #

Transform the values of a `Map` using their corresponding key

    mapWithKey (pure id) = id

    mapWithKey (liftA2 (.) f g) = mapWithKey f . mapWithKey g

    mapWithKey f mempty = mempty

    mapWithKey f (x <> y) = mapWithKey f x <> mapWithKey f y

    >>> mapWithKey (,) (fromList [("B",1),("A",2)])
    fromList [("B",("B",1)),("A",("A",2))]

traverseWithKey :: Ord k => Applicative f => (k -> a -> f b) -> Map k a -> f (Map k b) Source #

Traverse all of the key-value pairs in a `Map`, in their original order

    >>> traverseWithKey (,) (fromList [("B",1),("A",2)])
    ("BA",fromList [("B",1),("A",2)])

traverseWithKey_ :: Ord k => Applicative f => (k -> a -> f ()) -> Map k a -> f () Source #

Traverse all of the key-value pairs in a `Map`, in their original order where the result of the computation can be forgotten.

    >>> traverseWithKey_ (\k v -> print (k, v)) (fromList [("B",1),("A",2)])
    ("B",1)
    ("A",2)

foldMapWithKey :: (Monoid m, Ord k) => (k -> a -> m) -> Map k a -> m Source #

Fold all of the key-value pairs in a `Map`, in their original order

    >>> foldMapWithKey (,) (fromList [("B",[1]),("A",[2])])
    ("BA",[1,2])

# Conversions

toList :: Ord k => Map k v -> [(k, v)] Source #

Convert a `Map` to a list of key-value pairs in the original order of keys

    >>> toList (fromList [("B",1),("A",2)])
    [("B",1),("A",2)]

toMap :: Map k v -> Map k v Source #

Convert a `Dhall.Map.`Map`` to a `Data.Map.`Map``

    >>> toMap (fromList [("B",1),("A",2)]) -- Order is lost upon conversion
    fromList [("A",2),("B",1)]

keys :: Map k v -> [k] Source #

Return the keys from a `Map` in their original order

    >>> keys (fromList [("B",1),("A",2)])
    ["B","A"]