org.opencastproject.util.data.functions

Class Options

java.lang.Object

org.opencastproject.util.data.functions.Options

public final class Options
extends Object

Option related functions.

Field Summary

Fields

Modifier and Type	Field and Description
static Function<Boolean,Option<Boolean>>	toOption Function that turns true into some(true) and false into none.

Method Summary

Modifier and Type	Method and Description
static <A> Function<Option<A>,List<A>>	asList()
static <A,B> Function<A,Option<B>>	foreach(Function<? super A,? extends Option<? extends B>> f, Effect<? super B> e) Apply effect e to the result of f which is then returned.
static <A> Function<Option<A>,A>	getF()
static <A> Function<Option<A>,A>	getOrElse(A none)
static <A> Function<Option<A>,Boolean>	isNone() Option.isNone() as a function.
static <A> Function<Option<A>,Boolean>	isSome() Option.isSome() as a function.
static <A> Option<A>	join(Option<Option<A>> a) m (m a) -> m a
static <A,B,C> Function<A,Option<C>>	map(Function<? super A,? extends Option<? extends B>> f, Function<? super B,? extends C> g) Map g over the result of f.
static <A,B> Function<A,Option<B>>	never()
static <A> Function0<Option<A>>	never2()
static <A> Option<List<A>>	sequenceOpt(List<Option<A>> as) Sequence a list of options.
static Option<String>	toOption(boolean predicate, String message) Returns some(message) if predicate is false, none otherwise.

Methods inherited from class java.lang.Object

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

Field Detail

toOption

public static final Function<Boolean,Option<Boolean>> toOption

Function that turns true into some(true) and false into none.

Method Detail

join

public static <A> Option<A> join(Option<Option<A>> a)

m (m a) -> m a

asList

public static <A> Function<Option<A>,List<A>> asList()

never

public static <A,B> Function<A,Option<B>> never()

never2

public static <A> Function0<Option<A>> never2()

toOption

public static Option<String> toOption(boolean predicate,
                                      String message)

Returns some(message) if predicate is false, none otherwise.

sequenceOpt

public static <A> Option<List<A>> sequenceOpt(List<Option<A>> as)

Sequence a list of options. [Option a] -> Option [a]

map

public static <A,B,C> Function<A,Option<C>> map(Function<? super A,? extends Option<? extends B>> f,
                                                Function<? super B,? extends C> g)

Map g over the result of f.

foreach

public static <A,B> Function<A,Option<B>> foreach(Function<? super A,? extends Option<? extends B>> f,
                                                  Effect<? super B> e)

Apply effect e to the result of f which is then returned.

isNone

public static <A> Function<Option<A>,Boolean> isNone()

Option.isNone() as a function.

isSome

public static <A> Function<Option<A>,Boolean> isSome()

Option.isSome() as a function.

getOrElse

public static <A> Function<Option<A>,A> getOrElse(A none)

getF

public static <A> Function<Option<A>,A> getF()