eu.bandm.tools.ops

Class Null

java.lang.Object

eu.bandm.tools.ops.Null

public abstract class Null
extends Object

An abstract class that has no instances, and only the null reference.

Method Summary

Modifier and Type	Method and Description
static <A> A	check(A x) Deprecated. Use Objects.requireNonNull(Object) instead.
static <A> A	check(A x, String msg) Deprecated. Use Objects.requireNonNull(Object, String) instead.
static <A> A	check(String name, A x) Deprecated. Use Objects.requireNonNull(Object, String) instead.
static <A> boolean	equals(A x, A y) Deprecated. Use Objects.equals(java.lang.Object, java.lang.Object) instead.
static int	hashCode(Object x) Deprecated. Use Objects.hashCode(java.lang.Object) instead.
static <A,B> Function<A,B>	lift(Function<A,B> fun) Returns a variant of the given function that handles null arguments.

Methods inherited from class java.lang.Object

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

Method Detail

equals

public static <A> boolean equals(A x,
                                 A y)

Deprecated. Use Objects.equals(java.lang.Object, java.lang.Object) instead.

hashCode

public static int hashCode(Object x)

Deprecated. Use Objects.hashCode(java.lang.Object) instead.

check

public static <A> A check(A x)

Deprecated. Use Objects.requireNonNull(Object) instead.

check

public static <A> A check(A x,
                          String msg)

Deprecated. Use Objects.requireNonNull(Object, String) instead.

check

public static <A> A check(String name,
                          A x)

Deprecated. Use Objects.requireNonNull(Object, String) instead.

lift

public static <A,B> Function<A,B> lift(Function<A,B> fun)

Returns a variant of the given function that handles null arguments.

Parameters:

fun - a function

Returns:

a function that computes the same results as fun, but returns null immediately when applied to null.

Throws:

NullPointerException - if fun == null.