Class HashMultiDict<K, V>

A hash-based dictionary that can store multiple items with the same key.

import { HashMultiDict } from "scl"

Most methods in this collection, given that a proper hashing function is set up, are in Θ(1 + n/k). If you're out of luck, this characteristic can grow to O(n).

You can add as many items with the same key and value as you want, as the items will be stored next to each other.

const d = new HashMultiDict<number, string>()
d.emplace(1, 'foo') // ok
assert.strictEqual(d.getValue(1), 'foo')
d.emplace(1, 'bar') // ok
d.emplace(1, 'foo') // ok
const values = [...d.getValues(1)]
assert.strictEqual(values.length, 3)

Type Parameters

  • K
  • V

Hierarchy

  • MultiDictBase<K, V>
    • HashMultiDict

Constructors

constructor

Accessors

size

Methods

[iterator] add clear clone delete deleteAll deleteAt deleteKey emplace equalKeys findKey getValues has hasKey toRange

Constructors

constructor

  • new HashMultiDict<K, V>(
        opts?:
            | Iterable<[K, V], any, any>
            | HashIndex<[K, V], K>
            | HashDictOptions<K, V>,
    ): HashMultiDict<K, V>

  • Construct a new hash-based dictionary.

    const d = new HashMultiDict<number, string>()

    Similar to JavaScript's built-in map type, the constructor accepts a list of key-value pairs that will immediately be added to the resulting dictionary.

    const d = new HashMultiDict<number, string>([
      [1, 'one'],
      [2, 'two']
    ])

    The dictionary can be tweaked by providing a HashDictOptions-object, which allows to configure things like the default hashing function and value equality.

    const d = new HashMultiDict<number, string>({
      hash: num => num,
      keysEqual: (a, b) => a === b,
      valuesEqual: (a, b) => a === b,
    g   elements: [[1, 'one'], [2, 'two']]
    })

    Type Parameters

    • K
    • V

    Parameters

    • opts: Iterable<[K, V], any, any> | HashIndex<[K, V], K> | HashDictOptions<K, V> = {}

    Returns HashMultiDict<K, V>

Accessors

size

  • get size(): number

  • Count the amount of elements in the collection.

    ⚠️ In most cases, this should be an O(1) operation. However, there are cases where this can be an O(n) operation. Therefore, it is recommended to always cache the result in a local variable.

    Returns number

Methods

[iterator]

  • "[iterator]"(): IterableIterator<[K, V], any, any>

  • Returns IterableIterator<[K, V], any, any>

add

  • add(element: [K, V], hint?: unknown): AddResult<[K, V]>

  • Add an element to the collection. If the element already exists, update its value.

    The location where the element is placed depends on the collection type, and in the generic case there is no guarantee on the location where it is inserted.

    This method returns a pair with the first element indicating whether the element was added, while the second element refers to the actual location of the element.

    Parameters

    • element: [K, V]
    • Optionalhint: unknown

      A transparent object obtained by getAddHint.

    Returns AddResult<[K, V]>

clear

  • clear(): void

  • Remove all elements from this collection, effectively setting the collection to the empty collection.

    Returns void

clone

delete

  • delete(element: [K, V]): boolean

  • Remove an element from the collection. If multiple elements are matched, the collection picks one of them.

    Parameters

    • element: [K, V]

    Returns boolean

    true if the element was found, false otherwise.

deleteAll

  • deleteAll(element: [K, V]): number

  • Remove an element from the collection. If multiple elements are matched, the collection removes all of them.

    Parameters

    • element: [K, V]

    Returns number

    The amount of elements that was removed.

deleteAt

  • deleteAt(position: Cursor<[K, V]>): void

  • Remove the element pointed to by the iterator result from this collection.

    Parameters

    Returns void

deleteKey

  • deleteKey(key: K): number

  • Delete a pair from the underlying collection that has the given key as key.

    Returns the amount of items that have been deleted.

    Parameters

    • key: K

    Returns number

emplace

  • emplace(key: K, value: V): [boolean, Cursor<[K, V]>]

  • Creates a new pair and inserts it in the underlying collection.

    Parameters

    • key: K
    • value: V

    Returns [boolean, Cursor<[K, V]>]

equalKeys

findKey

  • findKey(key: K): undefined | Cursor<[K, V]>

  • Similar to Dict.getValue, except that it returns the pair that was inserted in the collection.

    Parameters

    • key: K

    Returns undefined | Cursor<[K, V]>

getValues

  • getValues(key: K): IterableIterator<V, any, any>

  • Get all values that are associated with the given key.

    Parameters

    • key: K

    Returns IterableIterator<V, any, any>

has

  • has(element: [K, V]): boolean

  • Checks if the collection holds the given element.

    Parameters

    • element: [K, V]

      The element to check membership of.

    Returns boolean

    True if the collections holds the given element, false otherwise.

hasKey

  • hasKey(key: K): boolean

  • Checks whether there a pair in this collection that has the given key.

    Parameters

    • key: K

    Returns boolean

toRange

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