me.lucko.helper.function

Class Predicates

java.lang.Object

me.lucko.helper.function.Predicates

@NonnullByDefault
public final class Predicates
extends Object

A collection of utilities for working with Predicates.

Method Summary

Modifier and Type	Method and Description
static <T> Predicate<T>	alwaysFalse() Returns a predicate which always returns false
static <T> Predicate<T>	alwaysTrue() Returns a predicate which always returns true
static <A,B> Predicate<A>	compose(Function<A,? extends B> function, Predicate<B> predicate) Returns a predicate which takes the input, passes it through the given function, and then obtains a result from the delegate predicate.
static <A,B> Predicate<A>	equalTo(Function<A,? extends B> composeFunction, Object target) Returns a predicate which takes the input, passes it through the given function, and then evaluates the result against equalTo(Object).
static <T> Predicate<T>	equalTo(Object target) Returns a predicate which returns true if the target is Object.equals(Object) to the input.
static <T> Predicate<T>	in(Collection<? extends T> collection) Returns a predicate which returns true if the input is contained within the given collection.
static <A,B> Predicate<A>	in(Function<A,? extends B> composeFunction, B... args) Returns a predicate which takes the input, passes it through the given function, and then evaluates the result against in(Object[]).
static <A,B> Predicate<A>	in(Function<A,? extends B> composeFunction, Collection<? extends B> collection) Returns a predicate which takes the input, passes it through the given function, and then evaluates the result against in(Collection).
static <T> Predicate<T>	in(T... args) Returns a predicate which returns true if the input is contained within the given var args.
static <T> Predicate<T>	instanceOf(Class<?> clazz) Returns a predicate which returns true if the input is an instance of the given class.
static <A,B> Predicate<A>	instanceOf(Function<A,? extends B> composeFunction, Class<?> clazz) Returns a predicate which takes the input, passes it through the given function, and then evaluates the result against instanceOf(Class).
static <T> Predicate<T>	isNull() Returns a predicate which returns true if the input is null, false otherwise.
static <A,B> Predicate<A>	isNull(Function<A,? extends B> composeFunction) Returns a predicate which takes the input, passes it through the given function, and then evaluates the result against isNull().
static <T> Predicate<T>	notNull() Returns a predicate which returns false if the input is null, true otherwise.
static <A,B> Predicate<A>	notNull(Function<A,? extends B> composeFunction) Returns a predicate which takes the input, passes it through the given function, and then evaluates the result against notNull().

Methods inherited from class java.lang.Object

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

Method Detail

compose

public static <A,B> Predicate<A> compose(Function<A,? extends B> function,
                                         Predicate<B> predicate)

Returns a predicate which takes the input, passes it through the given function, and then obtains a result from the delegate predicate.

Type Parameters:

A - the input type

B - the tested type

Parameters:

function - the function to map the input

predicate - the predicate to test the result of the mapping

Returns:

a composed predicate

alwaysTrue

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

Returns a predicate which always returns true

Type Parameters:

T - the type

Returns:

a predicate

alwaysFalse

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

Returns a predicate which always returns false

Type Parameters:

T - the type

Returns:

a predicate

isNull

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

Returns a predicate which returns true if the input is null, false otherwise.

Type Parameters:

T - the type

Returns:

a predicate

isNull

public static <A,B> Predicate<A> isNull(Function<A,? extends B> composeFunction)

Returns a predicate which takes the input, passes it through the given function, and then evaluates the result against isNull().

Type Parameters:

A - the input type

B - the tested type

Parameters:

composeFunction - the function to map the input

Returns:

a predicate

notNull

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

Returns a predicate which returns false if the input is null, true otherwise.

Type Parameters:

T - the type

Returns:

a predicate

notNull

public static <A,B> Predicate<A> notNull(Function<A,? extends B> composeFunction)

Returns a predicate which takes the input, passes it through the given function, and then evaluates the result against notNull().

Type Parameters:

A - the input type

B - the tested type

Parameters:

composeFunction - the function to map the input

Returns:

a predicate

equalTo

public static <T> Predicate<T> equalTo(@Nullable
                                       Object target)

Returns a predicate which returns true if the target is Object.equals(Object) to the input. If the target is null, the predicate returns true if the input is also null, false otherwise.

Type Parameters:

T - the type

Parameters:

target - the target object to compare against

Returns:

a predicate

equalTo

public static <A,B> Predicate<A> equalTo(Function<A,? extends B> composeFunction,
                                         @Nullable
                                         Object target)

Returns a predicate which takes the input, passes it through the given function, and then evaluates the result against equalTo(Object).

Type Parameters:

A - the input type

B - the tested type

Parameters:

composeFunction - the function to map the input

target - the target object to compare against

Returns:

a predicate

in

public static <T> Predicate<T> in(Collection<? extends T> collection)

Returns a predicate which returns true if the input is contained within the given collection.

Type Parameters:

T - the type

Parameters:

collection - the collection to query

Returns:

a predicate

in

public static <A,B> Predicate<A> in(Function<A,? extends B> composeFunction,
                                    Collection<? extends B> collection)

Returns a predicate which takes the input, passes it through the given function, and then evaluates the result against in(Collection).

Type Parameters:

A - the input type

B - the tested type

Parameters:

composeFunction - the function to map the input

collection - the collection to query

Returns:

a predicate

in

@SafeVarargs
public static <T> Predicate<T> in(T... args)

Returns a predicate which returns true if the input is contained within the given var args.

Type Parameters:

T - the type

Parameters:

args - the array to query

Returns:

a predicate

in

@SafeVarargs
public static <A,B> Predicate<A> in(Function<A,? extends B> composeFunction,
                                                 B... args)

Returns a predicate which takes the input, passes it through the given function, and then evaluates the result against in(Object[]).

Type Parameters:

A - the input type

B - the tested type

Parameters:

composeFunction - the function to map the input

args - the array to query

Returns:

a predicate

instanceOf

public static <T> Predicate<T> instanceOf(Class<?> clazz)

Returns a predicate which returns true if the input is an instance of the given class.

Type Parameters:

T - the type

Parameters:

clazz - the class

Returns:

a predicate

instanceOf

public static <A,B> Predicate<A> instanceOf(Function<A,? extends B> composeFunction,
                                            Class<?> clazz)

Returns a predicate which takes the input, passes it through the given function, and then evaluates the result against instanceOf(Class).

Type Parameters:

A - the input type

B - the tested type

Parameters:

composeFunction - the function to map the input

clazz - the class

Returns:

a predicate