Class: DoubleKeyMap

DoubleKeyMap

Simple map implementation that also keeps a reverse map whose keys are the values and values are the keys of the first map. For this reason the map can't contain duplicated values: collisions are handled by swapping values.

new DoubleKeyMap()

Crates and empty DoubleKeyMap

Method Summary

exist
Checks if there is a value in the first map at the specified key.
existReverse
Checks if there is a value in the second map at the specified key.
forEach
Executes a given callback passing each element of the first map as the only call parameter.
forEachReverse
Executes a given callback passing each element of the second map as the only call parameter.
get
Gets an element from the first map using the given key.
getReverse
Gets an element from the second map using the given key.
remove
Uses the given key to remove an element from the first map and the related element in the second map.
removeReverse
Uses the given key to remove an element from the second map and the related element in the first map.
set
Inserts new values in the maps.

Method Detail

exist(a) → {Boolean}

Checks if there is a value in the first map at the specified key.
Parameters:
Name Type Description
a Object the key to be used to get the element from the first map.
Returns:
true if the element exists, false otherwise.
Type
Boolean

existReverse(b) → {Boolean}

Checks if there is a value in the second map at the specified key.
Parameters:
Name Type Description
b Object the key to be used to get the element from the second map.
Returns:
true if the element exists, false otherwise.
Type
Boolean

forEach(callback)

Executes a given callback passing each element of the first map as the only call parameter.
Callbacks are executed synchronously before the method returns: calling DoubleKeyMap#set, DoubleKeyMap#remove or DoubleKeyMap#removeReverse during callback execution may result in a wrong iteration.
Parameters:
Name Type Description
callback function The callback to be called.

forEachReverse(callback)

Executes a given callback passing each element of the second map as the only call parameter.
Callbacks are executed synchronously before the method returns: calling DoubleKeyMap#set, DoubleKeyMap#remove or DoubleKeyMap#removeReverse during callback execution may result in a wrong iteration.
Parameters:
Name Type Description
callback function The callback to be called.

get(a) → {Object}

Gets an element from the first map using the given key.
Parameters:
Name Type Description
a Object the key to be used to get the element from the first map.
Returns:
the found value if any or an undefined value
Type
Object

getReverse(b) → {Object}

Gets an element from the second map using the given key.
Parameters:
Name Type Description
b Object the key to be used to get the element from the second map.
Returns:
the found value if any or an undefined value
Type
Object

remove(a)

Uses the given key to remove an element from the first map and the related element in the second map.
Parameters:
Name Type Description
a Object the key to be used to remove the element from the first map.

removeReverse(b)

Uses the given key to remove an element from the second map and the related element in the first map.
Parameters:
Name Type Description
b Object the key to be used to remove the element from the second map.

set(a, b)

Inserts new values in the maps. If one of the keys is already present in the respective map, its value is overwritten and the related entry on the other map is deleted. If both the keys are already present in their respective map a swapping to maintain uniqueness in both maps is performed.
Parameters:
Name Type Description
a Object the key to be used to insert the other value in the first map. It can't be null nor missing.
b Object the key to be used to insert the other value in the second map. It can't be null nor missing.
Throws:
if one (or both) of the specified values is null or missing.
Type
IllegalArgumentException