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DA.TextMap

TextMap - A map is an associative array data type composed of a collection of key/value pairs such that, each possible key appears at most once in the collection.

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Module Snapshot

Lifecycle

Stable.

Notices

Status: active Introduced in: 3.4.9 Removed in: - Warnings: 0 Deprecations: 0 Deprecated since: -

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Functions

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fromList

fromList : [(Text, a)] -> TextMap a
Create a map from a list of key/value pairs.

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fromListWithL

fromListWithL : (a -> a -> a) -> [(Text, a)] -> TextMap a
Create a map from a list of key/value pairs with a combining function. The combining function is only used when a key appears multiple times in the list and it takes two arguments: the first one is the new value being inserted at that key and the second one is the value accumulated so far at that key. Examples: 
>>> fromListWithL (++) [("A", [1]), ("A", [2]), ("B", [2]), ("B", [1]), ("A", [3])]
fromList [("A", [3, 2, 1]), ("B", [1, 2])]
>>> fromListWithL (++) [] == (empty : TextMap [Int])
True

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fromListWithR

fromListWithR : (a -> a -> a) -> [(Text, a)] -> TextMap a
Create a map from a list of key/value pairs like fromListWithL with the combining function flipped. Examples: 
>>> fromListWithR (++) [("A", [1]), ("A", [2]), ("B", [2]), ("B", [1]), ("A", [3])]
fromList [("A", [1, 2, 3]), ("B", [2, 1])]
>>> fromListWithR (++) [] == (empty : TextMap [Int])
True

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fromListWith

fromListWith : (a -> a -> a) -> [(Text, a)] -> TextMap a

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toList

toList : TextMap a -> [(Text, a)]
Convert the map to a list of key/value pairs where the keys are in ascending order.

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empty

empty : TextMap a
The empty map.

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size

size : TextMap a -> Int
Number of elements in the map.

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null

null : TextMap v -> Bool
Is the map empty?

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lookup

lookup : Text -> TextMap a -> Optional a
Lookup the value at a key in the map.

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member

member : Text -> TextMap v -> Bool
Is the key a member of the map?

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filter

filter : (v -> Bool) -> TextMap v -> TextMap v
Filter the TextMap using a predicate: keep only the entries where the value satisfies the predicate.

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filterWithKey

filterWithKey : (Text -> v -> Bool) -> TextMap v -> TextMap v
Filter the TextMap using a predicate: keep only the entries which satisfy the predicate.

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delete

delete : Text -> TextMap a -> TextMap a
Delete a key and its value from the map. When the key is not a member of the map, the original map is returned.

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singleton

singleton : Text -> a -> TextMap a
Create a singleton map.

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insert

insert : Text -> a -> TextMap a -> TextMap a
Insert a new key/value pair in the map. If the key is already present in the map, the associated value is replaced with the supplied value.

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insertWith

insertWith : (v -> v -> v) -> Text -> v -> TextMap v -> TextMap v
Insert a new key/value pair in the map. If the key is already present in the map, it is combined with the previous value using the given function f new_value old_value.

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union

union : TextMap a -> TextMap a -> TextMap a
The union of two maps, preferring the first map when equal keys are encountered.

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merge

merge : (Text -> a -> Optional c) -> (Text -> b -> Optional c) -> (Text -> a -> b -> Optional c) -> TextMap a -> TextMap b -> TextMap c
Merge two maps. merge f g h x y applies f to all key/value pairs whose key only appears in x, g to all pairs whose key only appears in y and h to all pairs whose key appears in both x and y. In the end, all pairs yielding Some are collected as the result.

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Orphan Typeclass Instances

  • instance Show a => Show (TextMap a)
  • instance Eq a => Eq (TextMap a)
  • instance Ord a => Ord (TextMap a)
  • instance Semigroup (TextMap b)
  • instance Monoid (TextMap b)
  • instance Functor TextMap
  • instance Foldable TextMap
  • instance Traversable TextMap