jodd.util.function

Interface Maybe<T>

All Superinterfaces:

java.lang.Iterable<T>

All Known Implementing Classes:

Maybe.Just

public interface Maybe<T>
extends java.lang.Iterable<T>

Slightly better Maybe monad. It does not have a get(), but it has or() :). Slightly better implementation of Optional, as there are no IF blocks all over the class.

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static class	Maybe.Just<T>

Method Summary

Modifier and Type	Method and Description
void	consumeJust(java.util.function.Consumer<T> consumer) Consumes value if present.
Maybe<T>	filter(java.util.function.Predicate<? super T> mapping)
<U> Maybe<U>	flatMap(java.util.function.Function<? super T,Maybe<U>> mapper) Flat map.
boolean	isJust() Returns true if value is present.
boolean	isNothing() Returns false if value is not present.
static <T> Maybe<T>	just(T theValue) Returns a JUST>
<U> Maybe<U>	map(java.util.function.Function<? super T,? extends U> mapper) Map.
<V> V	maybe(V defaultValue, java.util.function.Function<T,V> function) Takes a default value and a function.
static <T> Maybe<T>	nothing() Returns a NOTHING.
static <T> Maybe<T>	of(java.util.Optional<T> optionalValue)
static <T> Maybe<T>	of(T value) Static factory for Maybe.
java.util.Optional<T>	optional() Converts Maybe to the Java Optional.
Maybe<T>	or(Maybe<T> maybe) Use give maybe if this one is NOTHING.
Maybe<T>	or(java.util.function.Supplier<? extends Maybe<? extends T>> supplier) Use supplied value if this one is NOTHING.
Maybe<T>	or(T otherValue) Use a maybe of given value if this one is NOTHING.
java.util.stream.Stream<T>	stream() Returns empty or single-element stream.

Methods inherited from interface java.lang.Iterable

forEach, iterator, spliterator

Method Detail

of

static <T> Maybe<T> of(T value)

Static factory for Maybe.

of

static <T> Maybe<T> of(java.util.Optional<T> optionalValue)

isJust

boolean isJust()

Returns true if value is present.

isNothing

boolean isNothing()

Returns false if value is not present.

maybe

<V> V maybe(V defaultValue,
            java.util.function.Function<T,V> function)

Takes a default value and a function. If the Maybe value is Nothing, the function returns the default value. Otherwise, it applies the function to the value inside the Just and returns the result.

consumeJust

void consumeJust(java.util.function.Consumer<T> consumer)

Consumes value if present.

stream

java.util.stream.Stream<T> stream()

Returns empty or single-element stream.

or

Maybe<T> or(T otherValue)

Use a maybe of given value if this one is NOTHING.

or

Maybe<T> or(Maybe<T> maybe)

Use give maybe if this one is NOTHING.

or

Maybe<T> or(java.util.function.Supplier<? extends Maybe<? extends T>> supplier)

Use supplied value if this one is NOTHING.

map

<U> Maybe<U> map(java.util.function.Function<? super T,? extends U> mapper)

Map.

flatMap

<U> Maybe<U> flatMap(java.util.function.Function<? super T,Maybe<U>> mapper)

Flat map.

filter

Maybe<T> filter(java.util.function.Predicate<? super T> mapping)

optional

java.util.Optional<T> optional()

Converts Maybe to the Java Optional.

nothing

static <T> Maybe<T> nothing()

Returns a NOTHING.

just

static <T> Maybe<T> just(T theValue)

Returns a JUST>