com.google.common.base

Interface Function<F,T>

All Superinterfaces:

Function<F,T>

All Known Subinterfaces:

LoadingCache<K,V>

All Known Implementing Classes:

AbstractLoadingCache, ForwardingLoadingCache, ForwardingLoadingCache.SimpleForwardingLoadingCache

Functional Interface:

This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.

@GwtCompatible
 @FunctionalInterface
public interface Function<F,T>
extends Function<F,T>

Legacy version of java.util.function.Function.

The Functions class provides common functions and related utilities.

As this interface extends java.util.function.Function, an instance of this type can be used as a java.util.function.Function directly. To use a java.util.function.Function in a context where a com.google.common.base.Function is needed, use function::apply.

This interface is now a legacy type. Use java.util.function.Function (or the appropriate primitive specialization such as ToIntFunction) instead whenever possible. Otherwise, at least reduce explicit dependencies on this type by using lambda expressions or method references instead of classes, leaving your code easier to migrate in the future.

See the Guava User Guide article on the use of Function.

Since:

2.0

Author:

Kevin Bourrillion

Method Summary

Modifier and Type	Method and Description
T	apply(F input) Applies this function to the given argument.
boolean	equals(Object object) May return true if object is a Function that behaves identically to this function.

Methods inherited from interface java.util.function.Function

andThen, compose, identity

Method Detail

apply

@NullableDecl
 @CanIgnoreReturnValue
T apply(@NullableDecl
                                             F input)

Description copied from interface: java.util.function.Function

Applies this function to the given argument.

Specified by:

apply in interface Function<F,T>

Parameters:

input - the function argument

Returns:

the function result

equals

boolean equals(@NullableDecl
               Object object)

May return true if object is a Function that behaves identically to this function.

Warning: do not depend on the behavior of this method.

Historically, Function instances in this library have implemented this method to recognize certain cases where distinct Function instances would in fact behave identically. However, as code migrates to java.util.function, that behavior will disappear. It is best not to depend on it.

Overrides:

equals in class Object

Parameters:

object - the reference object with which to compare.

Returns:

true if this object is the same as the obj argument; false otherwise.

See Also:

Object.hashCode(), HashMap