javaslang

Class Predicates

java.lang.Object

javaslang.Predicates

public final class Predicates
extends Object

Defines general-purpose predicates which are particularly useful when working with API.Match.

Since:

2.0.0

Author:

Daniel Dietrich, Grzegorz Piwowarek

Method Summary

Modifier and Type	Method and Description
static <T> Predicate<T>	allOf(Predicate<? super T>... predicates) A combinator that checks if all of the given predicates are satisfied.
static <T> Predicate<T>	anyOf(Predicate<? super T>... predicates) A combinator that checks if at least one of the given predicates is satisfies.
static <T> Predicate<T>	instanceOf(Class<? extends T> type) Creates a Predicate that tests, if an object is instance of the specified type.
static <T> Predicate<T>	is(T value) Creates a Predicate that tests, if an object is equal to the specified value using Objects.equals(Object, Object) for comparison.
static <T> Predicate<T>	isIn(T... values) Creates a Predicate that tests, if an object is equal to at least one of the specified values using Objects.equals(Object, Object) for comparison.
static <T> Predicate<T>	isNotNull() Creates a Predicate that tests, if an object is not null
static <T> Predicate<T>	isNull() Creates a Predicate that tests, if an object is null
static <T> Predicate<T>	noneOf(Predicate<? super T>... predicates) A combinator that checks if none of the given predicates is satisfied.

Methods inherited from class java.lang.Object

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

Method Detail

instanceOf

public static <T> Predicate<T> instanceOf(Class<? extends T> type)

Creates a Predicate that tests, if an object is instance of the specified type.

Type Parameters:

T - Type of the given type

Parameters:

type - A type

Returns:

A new Predicate

Throws:

NullPointerException - if type is null

is

public static <T> Predicate<T> is(T value)

Creates a Predicate that tests, if an object is equal to the specified value using Objects.equals(Object, Object) for comparison.

Hint: Use is(null) instead of introducing a new predicate isNull()

Type Parameters:

T - value type

Parameters:

value - A value, may be null

Returns:

A new Predicate

isIn

@SafeVarargs
public static <T> Predicate<T> isIn(T... values)

Creates a Predicate that tests, if an object is equal to at least one of the specified values using Objects.equals(Object, Object) for comparison.

Type Parameters:

T - value type

Parameters:

values - an array of values of type T

Returns:

A new Predicate

Throws:

NullPointerException - if values is null

isNull

public static <T> Predicate<T> isNull()

Creates a Predicate that tests, if an object is null

Type Parameters:

T - value type

Returns:

A new Predicate

isNotNull

public static <T> Predicate<T> isNotNull()

Creates a Predicate that tests, if an object is not null

Type Parameters:

T - value type

Returns:

A new Predicate

allOf

@SafeVarargs
public static <T> Predicate<T> allOf(Predicate<? super T>... predicates)

A combinator that checks if all of the given predicates are satisfied.

By definition allOf is satisfied if the given predicates are empty.

Type Parameters:

T - closure over tested object types

Parameters:

predicates - An array of predicates

Returns:

A new Predicate

anyOf

@SafeVarargs
public static <T> Predicate<T> anyOf(Predicate<? super T>... predicates)

A combinator that checks if at least one of the given predicates is satisfies.

Type Parameters:

T - closure over tested object types

Parameters:

predicates - An array of predicates

Returns:

A new Predicate

noneOf

@SafeVarargs
public static <T> Predicate<T> noneOf(Predicate<? super T>... predicates)

A combinator that checks if none of the given predicates is satisfied.

Naturally noneOf is satisfied if the given predicates are empty.

Type Parameters:

T - closure over tested object types

Parameters:

predicates - An array of predicates

Returns:

A new Predicate