scala.collection.immutable
class HashMap

[source: `scala/collection/immutable/HashMap.scala`]

@serializable
`` `class` HashMap[A, B]
  `extends` Map[A, B]`with` HashTable[A]

  This class implements immutable maps using a hash table.

Author
  Martin Odersky
Version
  2.0, 19/01/2007

Type Summary
`type` | Entry

Value Summary
`protected var` | deltaSize : Int
`protected var` | later : HashMap[A, B]
`protected var` | oldKey : A
`protected var` | oldValue : Option[B]

Values and Variables inherited from HashTable
initialThreshold, table, tableSize, threshold

Method Summary
`def` | - (key : A) : Map[A, B] Remove a key from this map
`def` | elements : Iterator[(A, B)] Creates a new iterator over all elements contained in this object.
`def` | empty [C] : Map[A, C] This method returns a new map instance of the same class mapping keys of the same type to values of type `C`.
`def` | get (key : A) : Option[B] Check if this map maps `key` to a value and return the value if it exists.
`override def` | size : Int Returns the size of this hash table.
`def` | update [B1 >: B](key : A, value : B1) : Map[A, B1] This method allows one to create a new map with an additional mapping from `key` to `value`. If the map contains already a mapping for `key`, it will be overridden by this function.

Methods inherited from HashTable
loadFactor, initialSize, findEntry, addEntry, removeEntry, entries, clear, elemEquals, elemHashCode, improve, index

Methods inherited from Map
+, +, ++, ++, -, --, --, withDefault, withDefaultValue, transform, filter, +, incl, incl, excl, excl, mappingToString

Methods inherited from Map
getOrElse, isEmpty, apply, contains, isDefinedAt, keys, keySet, values, equals, hashCode, toString, default, projection

Methods inherited from Collection
toArray, stringPrefix

Methods inherited from Iterable
concat, ++, map, flatMap, takeWhile, dropWhile, take, drop, foreach, forall, exists, find, findIndexOf, indexOf, foldLeft, foldRight, /:, :\, reduceLeft, reduceRight, copyToBuffer, sameElements, toList, mkString, mkString, addString, addString, copyToArray, hasDefiniteSize

Methods inherited from PartialFunction
orElse, andThen

Methods inherited from Function1
compose

Methods inherited from AnyRef
getClass, clone, notify, notifyAll, wait, wait, wait, finalize, ==, !=, eq, ne, synchronized

Methods inherited from Any
==, !=, isInstanceOf, asInstanceOf

Type Details

`` `type` Entry

Value Details

`protected` `var` later : HashMap[A, B]

`protected` `var` oldKey : A

`protected` `var` oldValue : Option[B]

`protected` `var` deltaSize : Int

Method Details

`` `def` empty[C] : Map[A, C]

  This method returns a new map instance of the same class mapping keys of the same type to values of type `C`.

Overrides
  Map.empty

`` `def` get(key : A) : Option[B]

  Check if this map maps `key` to a value and return the value if it exists.

Parameters
  `key -` the key of the mapping of interest
Returns
  the value of the mapping, if it exists

`` `def` update[B1 >: B](key : A, value : B1) : Map[A, B1]

  This method allows one to create a new map with an additional mapping from `key` to `value`. If the map contains already a mapping for `key`, it will be overridden by this function.

Parameters
  `key -` ...
  `value -` ...
Returns
  the created map
Deprecated
  use `+({A, B})` instead

Overrides
  Map.update

`` `def` -(key : A) : Map[A, B]

  Remove a key from this map

Parameters
  `key -` the key to be removed
Returns
  If the map does not contain a binding for `key` it is returned unchanged. Otherwise, return a new map without a binding for `key`

Overrides
  Map.-

`override` `def` size : Int

  Returns the size of this hash table.

Overrides
  HashTable.size

`` `def` elements : Iterator[(A, B)]

  Creates a new iterator over all elements contained in this object.

Returns
  the new iterator