A Ceylon Map that wraps a JMap.

If the given map contains null elements, an optional Item type must be explicitly specified, for example:

CeylonMap<String,Object?>(javaStringObjectMap)

If a non-optional Item type is specified, an AssertionError will occur whenever a null item is encountered while iterating the map.

Initializer
CeylonMap(JMap<out Key,out Item> map)
Attributes
hashSource Codeshared actual Integer hash

The hash value of the value, which allows the value to be an element of a hash-based set or key of a hash-based map. Implementations must respect the constraint that:

  • if x==y then x.hash==y.hash.

Therefore, a class which refines equals must also refine hash.

In general, hash values vary between platforms and between executions of the same program.

Note that when executing on a Java Virtual Machine, the 64-bit Integer value returned by an implementation of hash is truncated to a 32-bit integer value by taking the exclusive disjunction of the 32 lowest-order bits with the 32 highest-order bits, before returning the value to the caller.

Refines Map.hash ultimately refines Object.hash
itemsSource Codeshared actual Collection<Item> items

A Collection containing the items stored in this map. An element can be stored under more than one key in the map, and so it can occur more than once in the resulting collection.

Refines Map.items
keysSource Codeshared actual Collection<Key> keys

The Category of all keys for which a value is defined by this Correspondence.

Refines Map.keys ultimately refines Correspondence.keys
sizeSource Codeshared actual Integer size

The number of elements returned by the iterator of this stream, if the iterator terminates. In the case of an infinite stream, this operation never terminates.

Inherited Attributes
Attributes inherited from: Object
Attributes inherited from: Collection<Element>
Attributes inherited from: Correspondence<Key,Item>
Attributes inherited from: Iterable<Element,Absent>
Attributes inherited from: Map<Key,Item>
Methods
cloneSource Codeshared actual default Map<Key,Item> clone()

A shallow copy of this collection, that is, a collection with identical elements which does not change if this collection changes. If this collection is immutable, it is acceptable to return a reference to this collection. If this collection is mutable, a newly instantiated collection must be returned.

Refines Map.clone ultimately refines Collection.clone
definesSource Codeshared actual Boolean defines(Object key)

Determines if there is a value defined for the given key.

Refines Map.defines ultimately refines Correspondence.defines
equalsSource Codeshared actual Boolean equals(Object that)

Determine if two values are equal.

For any two non-null objects x and y, x.equals(y) may be written as:

x == y 

Implementations should respect the constraints that:

  • if x===y then x==y (reflexivity),
  • if x==y then y==x (symmetry),
  • if x==y and y==z then x==z (transitivity).

Furthermore it is recommended that implementations ensure that if x==y then x and y have the same concrete class.

A class which explicitly refines equals() is said to support value equality, and the equality operator == is considered much more meaningful for such classes than for a class which simply inherits the default implementation of identity equality from Identifiable.

Note that an implementation of equals() that always returns false does satisfy the constraints given above, as long as the class does not inherit Identifiable. Therefore, in very rare cases where there is no reasonable definition of value equality for a class, for example, function references (Callable), it is acceptable for equals() to be defined to return false for every argument.

Refines Map.equals ultimately refines Object.equals
getSource Codeshared actual Item? get(Object key)

Returns the value defined for the given key, or null if there is no value defined for the given key.

For any instance c of Correspondence, c.get(key) may be written using the item operator:

c[key]
Refines Map.get ultimately refines Correspondence.get
iteratorSource Codeshared actual Iterator<Key->Item> iterator()

An iterator for the elements belonging to this stream.

If this is a nonempty stream with type {Element+}, the iterator must produce at least one element.

Inherited Methods
Methods inherited from: Object
Methods inherited from: Category<Element>
Methods inherited from: Collection<Element>
Methods inherited from: Correspondence<Key,Item>
Methods inherited from: Iterable<Element,Absent>
Methods inherited from: Map<Key,Item>