@FunctionalInterface public interface Long2DoubleFunction extends Function<Long,Double>, LongToDoubleFunction
Function; provides some additional methods that use polymorphism to avoid (un)boxing.
Type-specific versions of get(), put() and
remove() cannot rely on null to denote absence of
a key. Rather, they return a default
return value, which is set to 0/false at creation, but can be changed using
the defaultReturnValue() method.
For uniformity reasons, even functions returning objects implement the default
return value (of course, in this case the default return value is
initialized to null).
The default implementation of optional operations just throw an UnsupportedOperationException, except for the type-specific containsKey(), which return true. Generic versions of accessors delegate to
the corresponding type-specific counterparts following the interface rules.
Warning: to fall in line as much as possible with the
standard map interface, it is required that
standard versions of get(), put() and
remove() for maps with primitive-type keys or values return
null to denote missing keys rather than wrap the default
return value in an object. In case both keys and values are reference
types, the default return value must be returned instead, thus violating
the standard map interface when the default
return value is not null.
Function| Modifier and Type | Method and Description |
|---|---|
default double |
applyAsDouble(long operand) |
default boolean |
containsKey(long key)
Returns true if this function contains a mapping for the specified key.
|
default boolean |
containsKey(Object key)
Deprecated.
Please use the corresponding type-specific method instead.
|
default double |
defaultReturnValue()
Gets the default return value.
|
default void |
defaultReturnValue(double rv)
Sets the default return value (optional operation).
|
double |
get(long key)
Returns the value to which the given key is mapped.
|
default Double |
get(Object key)
Deprecated.
Please use the corresponding type-specific method instead.
|
default double |
put(long key,
double value)
Adds a pair to the map (optional operation).
|
default Double |
put(Long key,
Double value)
Deprecated.
Please use the corresponding type-specific method instead.
|
default double |
remove(long key)
Removes the mapping with the given key (optional operation).
|
default Double |
remove(Object key)
Deprecated.
Please use the corresponding type-specific method instead.
|
default double applyAsDouble(long operand)
applyAsDouble in interface LongToDoubleFunctiondefault double put(long key,
double value)
key - the key.value - the value.Function.put(Object,Object)double get(long key)
key - the key.Function.get(Object)default double remove(long key)
key - the key.Function.remove(Object)@Deprecated default Double put(Long key, Double value)
key - the key.value - the value.null if no value was present for the given key.Map.put(Object,Object)@Deprecated default Double get(Object key)
key - the key.null if no value was present for the given key.Map.get(Object)@Deprecated default Double remove(Object key)
key - the key.null if no value was present for the given key.Map.remove(Object)default boolean containsKey(long key)
Note that for some kind of functions (e.g., hashes) this method will always return true. In particular, this default implementation always returns true.
key - the key.key.Function.containsKey(Object)@Deprecated default boolean containsKey(Object key)
Note that for some kind of functions (e.g., hashes) this method will always return true. This default implementation, in particular, always return true.
key - the key.key.Map.containsKey(Object)default void defaultReturnValue(double rv)
get(), put() and remove() to
denote that the map does not contain the specified key. It must be
0/false/null by default.rv - the new default return value.defaultReturnValue()default double defaultReturnValue()
This default implementation just return the default null value
of the type (null for objects, 0 for scalars, false for Booleans).
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