de.javagl.common.functional

Class Functions

java.lang.Object

de.javagl.common.functional.Functions

public class Functions
extends Object

Utility methods for creating Function instances.

Method Summary

Modifier and Type	Method and Description
static <K,V> Function<K,V>	fromMap(Map<? super K,? extends V> map, V defaultValue) Create a Function that is backed by the given map.
static <S,T> Function<T,S>	invert(Function<? super S,? extends T> function, Iterable<? extends S> arguments) Returns a Function that is the inverse of the given Function, defined for the given arguments.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

invert

public static <S,T> Function<T,S> invert(Function<? super S,? extends T> function,
                                         Iterable<? extends S> arguments)

Returns a Function that is the inverse of the given Function, defined for the given arguments. For a given function f : S -> T and a set of arguments S0, the returned function will be a function that maps each t from T0 = f(S0) to the s from S0 for which f(s) = t. If the given function is not injective (that is, when multiple arguments are mapped to the same value), then the resulting function will return the last argument that was mapped to the respective ambiguous value, based on the order of the given arguments sequence.

Type Parameters:

S - The argument type

T - The value type

Parameters:

function - The Function

arguments - The arguments

Returns:

The inverse Function

fromMap

public static <K,V> Function<K,V> fromMap(Map<? super K,? extends V> map,
                                          V defaultValue)

Create a Function that is backed by the given map. Modifications of the given map will be visible through the returned function.

Type Parameters:

K - The key type

V - The value type

Parameters:

map - The backing map

defaultValue - The default value to return when a function argument is not contained in the map.

Returns:

The new function