ImmutableMap

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An ImmutableMap holds key-value pairs. Any value may be used as a key or value. Operations on an ImmutableMap do not mutate the map’s internal state.

Added in 0.5.4

No other changes yet.

import ImmutableMap from "immutablemap"

Types

Type declarations included in the ImmutableMap module.

ImmutableMap.ImmutableMap

type ImmutableMap<k, v>

Values

Functions and constants for working with ImmutableMaps.

ImmutableMap.empty

Added in 0.5.4

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empty : ImmutableMap<a, b>

An empty map

ImmutableMap.size

Added in 0.5.4

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size : ImmutableMap<a, b> -> Number

Provides the count of key-value pairs stored within the map.

Parameters:

param	type	description
`map`	`ImmutableMap<a, b>`	The map to inspect

Returns:

type	description
`Number`	The count of key-value pairs in the map

ImmutableMap.isEmpty

Added in 0.5.4

No other changes yet.

isEmpty : ImmutableMap<a, b> -> Bool

Determines if the map contains no key-value pairs.

Parameters:

param	type	description
`map`	`ImmutableMap<a, b>`	The map to inspect

Returns:

type	description
`Bool`	`true` if the given map is empty or `false` otherwise

ImmutableMap.set

Added in 0.5.4

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set : (a, b, ImmutableMap<a, b>) -> ImmutableMap<a, b>

Produces a new map containing a new key-value pair. If the key already exists in the map, the value is replaced.

Parameters:

param	type	description
`key`	`a`	The unique key in the map
`value`	`b`	The value to store
`map`	`ImmutableMap<a, b>`	The base map

Returns:

type	description
`ImmutableMap<a, b>`	A new map containing the new key-value pair

ImmutableMap.get

Added in 0.5.4

No other changes yet.

get : (a, ImmutableMap<a, b>) -> Option<b>

Retrieves the value for the given key.

Parameters:

param	type	description
`key`	`a`	The key to access
`map`	`ImmutableMap<a, b>`	The map to access

Returns:

type	description
`Option<b>`	`Some(value)` if the key exists in the map or `None` otherwise

ImmutableMap.contains

Added in 0.5.4

No other changes yet.

contains : (a, ImmutableMap<a, b>) -> Bool

Determines if the map contains the given key. In such a case, it will always contain a value for the given key.

Parameters:

param	type	description
`key`	`a`	The key to search for
`map`	`ImmutableMap<a, b>`	The map to search

Returns:

type	description
`Bool`	`true` if the map contains the given key or `false` otherwise

ImmutableMap.remove

Added in 0.5.4

No other changes yet.

remove : (a, ImmutableMap<a, b>) -> ImmutableMap<a, b>

Produces a new map without the key-value pair corresponding to the given key. If the key doesn’t exist in the map, the map will be returned unmodified.

Parameters:

param	type	description
`key`	`a`	The key to exclude
`map`	`ImmutableMap<a, b>`	The map to exclude from

Returns:

type	description
`ImmutableMap<a, b>`	A new map without the given key

ImmutableMap.update

Added in 0.5.4

No other changes yet.

1
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update :
  (a, (Option<b> -> Option<b>), ImmutableMap<a, b>) -> ImmutableMap<a, b>

Produces a new map by calling an updater function that receives the previously stored value as an Option and returns the new value to be stored as an Option. If the key didn’t exist previously, the value will be None. If None is returned from the updater function, the key-value pair is excluded.

Parameters:

param	type	description
`key`	`a`	The unique key in the map
`fn`	`Option<b> -> Option<b>`	The updater function
`map`	`ImmutableMap<a, b>`	The base map

Returns:

type	description
`ImmutableMap<a, b>`	A new map with the value at the given key modified according to the function’s output

ImmutableMap.forEach

Added in 0.5.4

No other changes yet.

forEach : (((a, b) -> Void), ImmutableMap<a, b>) -> Void

Iterates the map, calling an iterator function with each key and value.

Parameters:

param	type	description
`fn`	`(a, b) -> Void`	The iterator function to call with each key and value
`map`	`ImmutableMap<a, b>`	The map to iterate

ImmutableMap.reduce

Added in 0.5.4

No other changes yet.

reduce : (((a, b, c) -> a), a, ImmutableMap<b, c>) -> a

Combines all key-value pairs of a map using a reducer function.

Parameters:

param	type	description
`fn`	`(a, b, c) -> a`	The reducer function to call on each key and value, where the value returned will be the next accumulator value
`init`	`a`	The initial value to use for the accumulator on the first iteration
`map`	`ImmutableMap<b, c>`	The map to iterate

Returns:

type	description
`a`	The final accumulator returned from `fn`

ImmutableMap.keys

Added in 0.5.4

No other changes yet.

keys : ImmutableMap<a, b> -> List<a>

Enumerates all keys in the given map.

Parameters:

param	type	description
`map`	`ImmutableMap<a, b>`	The map to enumerate

Returns:

type	description
`List<a>`	A list containing all keys from the given map

ImmutableMap.values

Added in 0.5.4

No other changes yet.

values : ImmutableMap<a, b> -> List<b>

Enumerates all values in the given map.

Parameters:

param	type	description
`map`	`ImmutableMap<a, b>`	The map to enumerate

Returns:

type	description
`List<b>`	A list containing all values from the given map

ImmutableMap.filter

Added in 0.5.4

No other changes yet.

filter : (((a, b) -> Bool), ImmutableMap<a, b>) -> ImmutableMap<a, b>

Produces a new map excluding the key-value pairs where a predicate function returns false.

Parameters:

param	type	description
`fn`	`(a, b) -> Bool`	The predicate function to indicate which key-value pairs to exclude from the map, where returning `false` indicates the key-value pair should be excluded
`map`	`ImmutableMap<a, b>`	The map to iterate

Returns:

type	description
`ImmutableMap<a, b>`	A new map excluding the key-value pairs not fulfilling the predicate

ImmutableMap.reject

Added in 0.5.4

No other changes yet.

reject : (((a, b) -> Bool), ImmutableMap<a, b>) -> ImmutableMap<a, b>

Produces a new map excluding the key-value pairs where a predicate function returns true.

Parameters:

param	type	description
`fn`	`(a, b) -> Bool`	The predicate function to indicate which key-value pairs to exclude from the map, where returning `true` indicates the key-value pair should be excluded
`map`	`ImmutableMap<a, b>`	The map to iterate

Returns:

type	description
`ImmutableMap<a, b>`	A new map excluding the key-value pairs fulfilling the predicate

ImmutableMap.fromList

Added in 0.5.4

No other changes yet.

fromList : List<(a, b)> -> ImmutableMap<a, b>

Creates a map from a list.

Parameters:

param	type	description
`list`	`List<(a, b)>`	The list to convert

Returns:

type	description
`ImmutableMap<a, b>`	A map containing all key-value pairs from the list

ImmutableMap.toList

Added in 0.5.4

No other changes yet.

toList : ImmutableMap<a, b> -> List<(a, b)>

Enumerates all key-value pairs in the given map.

Parameters:

param	type	description
`map`	`ImmutableMap<a, b>`	The map to enumerate

Returns:

type	description
`List<(a, b)>`	A list containing all key-value pairs from the given map

ImmutableMap.fromArray

Added in 0.5.4

No other changes yet.

fromArray : Array<(a, b)> -> ImmutableMap<a, b>

Creates a map from an array.

Parameters:

param	type	description
`array`	`Array<(a, b)>`	The array to convert

Returns:

type	description
`ImmutableMap<a, b>`	A map containing all key-value pairs from the array

ImmutableMap.toArray

Added in 0.5.4

No other changes yet.

toArray : ImmutableMap<a, b> -> Array<(a, b)>

Converts a map into an array of its key-value pairs.

Parameters:

param	type	description
`map`	`ImmutableMap<a, b>`	The map to convert

Returns:

type	description
`Array<(a, b)>`	An array containing all key-value pairs from the given map