com.atlassian.servicedesk.api.util.fp

Class FpKit

java.lang.Object

com.atlassian.servicedesk.api.util.fp.FpKit

@PublicApi
public class FpKit
extends Object

A set of functional helper methods to help when working with Fugue constructs and JDK8 constructs

Constructor Summary

Constructors

Constructor and Description
FpKit()

Method Summary

Modifier and Type	Method and Description
static <T,R> List<R>	flatMap(List<T> list, com.google.common.base.Function<T,List<R>> mapper) Allow you flat map a List of type T into a List of type R with less stream syntax
static <L,R> Object	foldToObject(com.atlassian.fugue.Either<L,R> either) Some times you just need the Either's value as an Object.
static <T,S> List<T>	map(Collection<? extends S> source, com.google.common.base.Function<S,T> f) Allows you to map a Collection of S into a List of T with less stream syntax
static NoExceptionsCallable<com.atlassian.fugue.Unit>	runnableToNoExceptionsCallable(Runnable runnable) Turns a runnable into a callable
static <L,R> com.atlassian.fugue.Either<L,R>	toEither(Optional<R> optional, com.google.common.base.Supplier<L> leftSupplier) Allows you to convert JDK8 Optional into a Fugue Either with the optional value in as the right if present.
static <T> List<T>	toList(com.atlassian.fugue.Option<T> option) Converts an option to a list.
static <T> Object	toObject(T someObject) Somes times in FP lands you need to turn generic types into the most basic type of all.
static <T> com.atlassian.fugue.Option<T>	toOption(Optional<T> optional) Allows you to convert JDK8 Optional into a Fugue Option
static <T> Optional<T>	toOptional(com.atlassian.fugue.Option<T> option) Allows you to convert JDK8 Optional into a Fugue Option

Methods inherited from class java.lang.Object

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

Constructor Detail

FpKit

public FpKit()

Method Detail

map

public static <T,S> List<T> map(Collection<? extends S> source,
                                com.google.common.base.Function<S,T> f)

Allows you to map a Collection of S into a List of T with less stream syntax

Parameters:

source - the source

f - the mapper

Returns:

a List of T

flatMap

public static <T,R> List<R> flatMap(List<T> list,
                                    com.google.common.base.Function<T,List<R>> mapper)

Allow you flat map a List of type T into a List of type R with less stream syntax

Parameters:

list - the source list with type T

mapper - the mapping function

Returns:

a list of R

toList

public static <T> List<T> toList(com.atlassian.fugue.Option<T> option)

Converts an option to a list. e.g. use this when you need to flatten a list of options.

Parameters:

option - an option of type t

Returns:

a list of t with either zero (if option is empty) or 1 (if option is defined) element.

toOption

public static <T> com.atlassian.fugue.Option<T> toOption(Optional<T> optional)

Allows you to convert JDK8 Optional into a Fugue Option

Parameters:

optional - the optional to convert

Returns:

a Fugue Option

toEither

public static <L,R> com.atlassian.fugue.Either<L,R> toEither(Optional<R> optional,
                                                             com.google.common.base.Supplier<L> leftSupplier)

Allows you to convert JDK8 Optional into a Fugue Either with the optional value in as the right if present.

Parameters:

optional - the optional to convert

leftSupplier - a supplier of the left side

Returns:

a Fugue Either

toOptional

public static <T> Optional<T> toOptional(com.atlassian.fugue.Option<T> option)

Allows you to convert JDK8 Optional into a Fugue Option

Parameters:

option - the option to convert

Returns:

a JDK8 Optional

toObject

public static <T> Object toObject(T someObject)

Somes times in FP lands you need to turn generic types into the most basic type of all. This is that method!.

Parameters:

someObject - some object

Returns:

it downcast to an object

foldToObject

public static <L,R> Object foldToObject(com.atlassian.fugue.Either<L,R> either)

Some times you just need the Either's value as an Object. This is that method.

Parameters:

either - the Either containing objects

Returns:

either the left or right values downcast as an Object

runnableToNoExceptionsCallable

public static NoExceptionsCallable<com.atlassian.fugue.Unit> runnableToNoExceptionsCallable(Runnable runnable)

Turns a runnable into a callable

Parameters:

runnable - the code to run

Returns:

a callable that runs the runnable and returns nothing useful