A map from parameterized keys to values with the same parameter type.

Return empty map

Return map containing a single element

Insert a binding into the map, replacing the existing binding if needed.

insertWith f new m inserts the binding into m.

It inserts f new old if m already contains an equivalent value old, and new otherwise. It returns an Unchanged value if the map stays the same size and an Updated value if a new entry was inserted.

Delete a value from the map if present.

Left-biased union of two maps. The resulting map will contain the union of the keys of the two arguments. When a key is contained in both maps the value from the first map will be preserved.

Applies a function to the pairwise common elements of two maps.

Formally, we have that intersectWithKeyMaybe f x y contains a binding from a key k to a value v if and only if x and y bind k to x_k and y_k and f x_k y_k = Just v.

Return true if map is empty

Lookup value in map.

findWithDefault d k m returns the value bound to k in the map m, or d if k is not bound in the map.

Return true if key is bound in map.

Return true if key is not bound in map.

Return all keys of the map in ascending order.

Return all elements of the map in the ascending order of their keys.

Create a Map from a list of pairs.

Return list of key-values pairs in map.

Return list of key-values pairs in map in ascending order.

Return list of key-values pairs in map in descending order.

Generate a map from a foldable collection of keys and a function from keys to values.

Generate a map from a foldable collection of keys and a monadic function from keys to values.

Return entries with values that satisfy a predicate.

Return key-value pairs that satisfy a predicate.

filterGt k m returns submap of m that only contains entries that are larger than k.

filterLt k m returns submap of m that only contains entries that are smaller than k.

Perform a left fold with the key also provided.

Perform a strict left fold with the key also provided.

Perform a right fold with the key also provided.

Perform a strict right fold with the key also provided.

Fold the keys and values using the given monoid.

A monadic left-to-right fold over keys and values in the map.

A monadic right-to-left fold over keys and values in the map.

Modify elements in a map

Apply function to all elements in map.

Map elements and collect Just results.

Map keys and elements and collect Just results.

Traverse elements in a map

Traverse elements in a map without returning result.

Traverse keys/values and collect the Just results.

UpdateRequest tells what to do with a found value

Updated a contains a value that has been flagged on whether it was modified by an operation.

Log-time algorithm that allows a value at a specific key to be added, replaced, or deleted.

Merge bindings in two maps to get a third.

The first function is used to merge elements that occur under the same key in both maps. Return Just to add an entry into the resulting map under this key or Nothing to remove this key from the resulting map.

The second function will be applied to submaps of the first map argument where no keys overlap with the second map argument. The result of this function must be a map with a subset of the keys of its argument. This means the function can alter the values of its argument and it can remove key-value pairs from it, but it can break MapF ordering invariants if it introduces new keys.

Third function is analogous to the second function except that it applies to the second map argument of mergeWithKeyM instead of the first.

Common examples of the two functions include id when constructing a union or const empty when constructing an intersection.

Merge bindings in two maps using monadic actions to get a third.

The first function is used to merge elements that occur under the same key in both maps. Return Just to add an entry into the resulting map under this key or Nothing to remove this key from the resulting map.

The second function will be applied to submaps of the first map argument where no keys overlap with the second map argument. The result of this function must be a map with a subset of the keys of its argument. This means the function can alter the values of its argument and it can remove key-value pairs from it, but it can break MapF ordering invariants if it introduces new keys.

Third function is analogous to the second function except that it applies to the second map argument of mergeWithKeyM instead of the first.

Common examples of the two functions include id when constructing a union or const empty when constructing an intersection.

Like a 2-tuple, but with an existentially quantified parameter that both of the elements share.