Optional

data class Optional<T>

This type represents T as not only potentially nullable data, but also as a data which can not be presented. This type will be useful in cases when T is nullable and null as valuable data too in time of data absence should be presented by some third type.

Let's imagine, you have nullable name in some database. In case when name is not nullable everything is clear - null will represent absence of row in the database. In case when name is nullable null will be a little bit dual-meaning, cause this null will say nothing about availability of the row (of course, it is exaggerated example)

Types

Companion

jvm

object Companion

Properties

data

jvm

val data: T?

dataPresented

jvm

val dataPresented: Boolean

Extensions

dataOrElse

android

inline fun <T> Optional<T>.dataOrElse(block: () -> T): T

Returns Optional.data if Optional.dataPresented of this is true, or call block and returns the result of it

common

inline fun <T> Optional<T>.dataOrElse(block: () -> T): T

Returns Optional.data if Optional.dataPresented of this is true, or call block and returns the result of it

jvm

inline fun <T> Optional<T>.dataOrElse(block: () -> T): T

Returns Optional.data if Optional.dataPresented of this is true, or call block and returns the result of it

dataOrNull

android

fun <T> Optional<T>.dataOrNull(): T?

Returns Optional.data if Optional.dataPresented of this is true, or null otherwise

common

fun <T> Optional<T>.dataOrNull(): T?

Returns Optional.data if Optional.dataPresented of this is true, or null otherwise

jvm

fun <T> Optional<T>.dataOrNull(): T?

Returns Optional.data if Optional.dataPresented of this is true, or null otherwise

dataOrThrow

android

fun <T> Optional<T>.dataOrThrow(throwable: Throwable): T

Returns Optional.data if Optional.dataPresented of this is true, or throw throwable otherwise

common

fun <T> Optional<T>.dataOrThrow(throwable: Throwable): T

Returns Optional.data if Optional.dataPresented of this is true, or throw throwable otherwise

jvm

fun <T> Optional<T>.dataOrThrow(throwable: Throwable): T

Returns Optional.data if Optional.dataPresented of this is true, or throw throwable otherwise

mapOnAbsent

android

inline fun <T, R> Optional<T>.mapOnAbsent(block: () -> R): R?

Will call block when data presented (Optional.dataPresented == true)

common

inline fun <T, R> Optional<T>.mapOnAbsent(block: () -> R): R?

Will call block when data presented (Optional.dataPresented == true)

jvm

inline fun <T, R> Optional<T>.mapOnAbsent(block: () -> R): R?

Will call block when data presented (Optional.dataPresented == true)

mapOnPresented

android

inline fun <T, R> Optional<T>.mapOnPresented(block: (T) -> R): R?

Will call block when data presented (Optional.dataPresented == true)

common

inline fun <T, R> Optional<T>.mapOnPresented(block: (T) -> R): R?

Will call block when data presented (Optional.dataPresented == true)

jvm

inline fun <T, R> Optional<T>.mapOnPresented(block: (T) -> R): R?

Will call block when data presented (Optional.dataPresented == true)

onAbsent

android

inline fun <T> Optional<T>.onAbsent(block: () -> Unit): Optional<T>

Will call block when data absent (Optional.dataPresented == false)

common

inline fun <T> Optional<T>.onAbsent(block: () -> Unit): Optional<T>

Will call block when data absent (Optional.dataPresented == false)

jvm

inline fun <T> Optional<T>.onAbsent(block: () -> Unit): Optional<T>

Will call block when data absent (Optional.dataPresented == false)

onPresented

android

inline fun <T> Optional<T>.onPresented(block: (T) -> Unit): Optional<T>

Will call block when data presented (Optional.dataPresented == true)

common

inline fun <T> Optional<T>.onPresented(block: (T) -> Unit): Optional<T>

Will call block when data presented (Optional.dataPresented == true)

jvm

inline fun <T> Optional<T>.onPresented(block: (T) -> Unit): Optional<T>

Will call block when data presented (Optional.dataPresented == true)

Optional

See also

Types

Properties

Extensions