Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Features
Speaker Deck
PRO
Sign in
Sign up for free
Search
Search
Java Wars VIII: The Function Awakens
Search
Grzegorz Piwowarek
April 11, 2016
Programming
0
680
Java Wars VIII: The Function Awakens
Grzegorz Piwowarek
April 11, 2016
Tweet
Share
More Decks by Grzegorz Piwowarek
See All by Grzegorz Piwowarek
Javaslang DevoxxBE 2016
pivovarit
1
130
Javaslang DevoxxMA
pivovarit
2
1k
JavaSlang JavaDayKiev 2016
pivovarit
0
76
Javaslang - functional Java done right
pivovarit
0
220
Java 8 vs. Checked Exceptions
pivovarit
0
110
Java 8: Lambdas, Monads and Java Collections
pivovarit
1
110
Other Decks in Programming
See All in Programming
LINEヤフー データグループ紹介
lycorp_recruit_jp
0
1.7k
Modern Angular with Signals and Signal Store:New Rules for Your Architecture @enterJS Advanced Angular Day 2025
manfredsteyer
PRO
0
170
設計やレビューに悩んでいるPHPerに贈る、クリーンなオブジェクト設計の指針たち
panda_program
6
1.8k
#QiitaBash MCPのセキュリティ
ryosukedtomita
0
730
初学者でも今すぐできる、Claude Codeの生産性を10倍上げるTips
s4yuba
3
3.1k
Google Agent Development Kit でLINE Botを作ってみた
ymd65536
2
210
PHPでWebSocketサーバーを実装しよう2025
kubotak
0
250
Flutterで備える!Accessibility Nutrition Labels完全ガイド
yuukiw00w
0
140
なぜ「共通化」を考え、失敗を繰り返すのか
rinchoku
1
620
システム成長を止めない!本番無停止テーブル移行の全貌
sakawe_ee
1
160
XP, Testing and ninja testing
m_seki
3
220
データの民主化を支える、透明性のあるデータ利活用への挑戦 2025-06-25 Database Engineering Meetup#7
y_ken
0
340
Featured
See All Featured
Raft: Consensus for Rubyists
vanstee
140
7k
Building a Scalable Design System with Sketch
lauravandoore
462
33k
Templates, Plugins, & Blocks: Oh My! Creating the theme that thinks of everything
marktimemedia
31
2.4k
Visualizing Your Data: Incorporating Mongo into Loggly Infrastructure
mongodb
46
9.6k
Evolution of real-time – Irina Nazarova, EuRuKo, 2024
irinanazarova
8
800
Six Lessons from altMBA
skipperchong
28
3.9k
The Web Performance Landscape in 2024 [PerfNow 2024]
tammyeverts
8
680
Site-Speed That Sticks
csswizardry
10
670
How to Create Impact in a Changing Tech Landscape [PerfNow 2023]
tammyeverts
53
2.8k
Building Adaptive Systems
keathley
43
2.6k
Building Better People: How to give real-time feedback that sticks.
wjessup
367
19k
Fight the Zombie Pattern Library - RWD Summit 2016
marcelosomers
233
17k
Transcript
Grzegorz Piwowarek
[email protected]
GitHub, Twitter :: @pivovarit
GitHub, Twitter :: @pivovarit VISIONS OF TONDAL.PL
None
None
None
None
Why?
//TODO: -lambda expressions -java.util.function -monad -java.util.Optional -java.util.stream.Stream GitHub, Twitter ::
@pivovarit
lambda expressions GitHub, Twitter :: @pivovarit
lambda expressions (...) -> statement - Anonymous function GitHub, Twitter
:: @pivovarit
lambda expressions x -> x + 1 GitHub, Twitter ::
@pivovarit
lambda expressions x -> x + 1 GitHub, Twitter ::
@pivovarit () -> 42
lambda expressions x -> x + 1 GitHub, Twitter ::
@pivovarit () -> 42 () -> {return 42;}
lambda expressions x -> x + 1 GitHub, Twitter ::
@pivovarit () -> 42 (x, y) -> {} () -> {return 42;}
lambda expressions x -> x + 1 - No type
information GitHub, Twitter :: @pivovarit
method references GitHub, Twitter :: @pivovarit
java.util.function GitHub, Twitter :: @pivovarit
Function<T, R>, BiFunction<T,U,R> Consumer<T> extends Function<T,Void> Supplier<T> extends Function<Void, T>
Predicate<T> extends Function<T, Boolean> UnaryOperator<T> extends Function<T, T> BinaryOperator<T> extends BiFunction<T,T,T> GitHub, Twitter :: @pivovarit
Function<T, R>, BiFunction<T,U,R> Consumer<T> extends Function<T,Void> Supplier<T> extends Function<Void, T>
Predicate<T> extends Function<T, Boolean> UnaryOperator<T> extends Function<T, T> BinaryOperator<T> extends BiFunction<T,T,T> GitHub, Twitter :: @pivovarit
Function<T, R>, BiFunction<T,U,R> Consumer<T> extends Function<T,Void> Supplier<T> extends Function<Void, T>
Predicate<T> extends Function<T, Boolean> UnaryOperator<T> extends Function<T, T> BinaryOperator<T> extends BiFunction<T,T,T> GitHub, Twitter :: @pivovarit
Function<T, R>, BiFunction<T,U,R> Consumer<T> extends Function<T,Void> Supplier<T> extends Function<Void, T>
Predicate<T> extends Function<T, Boolean> UnaryOperator<T> extends Function<T, T> BinaryOperator<T> extends BiFunction<T,T,T> GitHub, Twitter :: @pivovarit
Function<T, R>, BiFunction<T,U,R> Consumer<T> extends Function<T,Void> Supplier<T> extends Function<Void, T>
Predicate<T> extends Function<T, Boolean> UnaryOperator<T> extends Function<T, T> BinaryOperator<T> extends BiFunction<T,T,T> GitHub, Twitter :: @pivovarit
MONAD GitHub, Twitter :: @pivovarit
GitHub, Twitter :: @pivovarit
GOOGLE IMAGES...
GOOGLE IMAGES...
GOOGLE IMAGES...
GOOGLE IMAGES...
GOOGLE IMAGES...
GOOGLE IMAGES...
GOOGLE IMAGES...
GOOGLE IMAGES...
... GitHub, Twitter :: @pivovarit
MONAD Design pattern http://got-steam.com/ GitHub, Twitter :: @pivovarit
Why bother? : Boilerplate-- Readability++ Complexity-- GitHub, Twitter :: @pivovarit
Imperative approach GitHub, Twitter :: @pivovarit
Declarative approach GitHub, Twitter :: @pivovarit
Generic type: "unit" method: "bind" method: MONAD GitHub, Twitter ::
@pivovarit
Generic type: "unit" method: "bind" method: MONAD GitHub, Twitter ::
@pivovarit
Generic type: "unit" method: "bind" method: MONAD GitHub, Twitter ::
@pivovarit
Generic type: "unit" method: "bind" method: MONAD GitHub, Twitter ::
@pivovarit
GitHub, Twitter :: @pivovarit
GitHub, Twitter :: @pivovarit
GitHub, Twitter :: @pivovarit
http://www.ivanaborovnjak.com/project/box-in-a-box/ GitHub, Twitter :: @pivovarit
Solution GitHub, Twitter :: @pivovarit
Monads in Java 8 Optional Stream CompletableFuture GitHub, Twitter ::
@pivovarit
Monads in Java 8 Optional Stream CompletableFuture GitHub, Twitter ::
@pivovarit
Optional Encapsulation of operations on optional values GitHub, Twitter ::
@pivovarit
Optional Encapsulation of operations on optional values GitHub, Twitter ::
@pivovarit
Optional type: "unit": "bind": GitHub, Twitter :: @pivovarit
Optional type: Optional<T> "unit": "bind": GitHub, Twitter :: @pivovarit
Optional type: Optional<T> "unit": Optional.ofNullable(), Optional.of() "bind": GitHub, Twitter ::
@pivovarit
Optional type: Optional<T> "unit": Optional.ofNullable(), Optional.of() "bind": Optional.flatMap(), Optional.map() GitHub,
Twitter :: @pivovarit
Filtering an Optional .filter(Predicate<T>) GitHub, Twitter :: @pivovarit
Unwrapping an Optional .get() .orElse(T default) .orElseGet(Supplier<T>) .orElseThrow(Supplier<Ex>) .ifPresent(Consumer<T>) GitHub,
Twitter :: @pivovarit
GitHub, Twitter :: @pivovarit http://theworryfreelife.com/wp-content/uploads/2015/08/comfort-zone.jpg
Java 7 style GitHub, Twitter :: @pivovarit
Java 8 style GitHub, Twitter :: @pivovarit
Java 7,5 style ;) GitHub, Twitter :: @pivovarit
Java 7,5 style ;) GitHub, Twitter :: @pivovarit
GitHub, Twitter :: @pivovarit
GitHub, Twitter :: @pivovarit
Stream Encapsulation of operations on multiple items GitHub, Twitter ::
@pivovarit
Stream type: Stream<T> "unit": Stream.of(), Arrays.stream(), Collection.stream() "bind": Stream.flatMap() GitHub,
Twitter :: @pivovarit
Stream GitHub, Twitter :: @pivovarit
Stream GitHub, Twitter :: @pivovarit
Stream GitHub, Twitter :: @pivovarit
Imperative vs. Declarative GitHub, Twitter :: @pivovarit
Imperative vs. Declarative GitHub, Twitter :: @pivovarit
Stream && Optional GitHub, Twitter :: @pivovarit
Stream lazy-initialized nonreusable GitHub, Twitter :: @pivovarit
intermediate operations .map() .flatMap() .filter() .peek() GitHub, Twitter :: @pivovarit
intermediate operations .map() .flatMap() .filter() .peek() Stream not consumed: does
not print anything GitHub, Twitter :: @pivovarit
Consuming Stream .forEach(Consumer<T>) .collect() .reduce(BinaryOperator<T>) .allMatch(), anyMatch(), noneMatch() .findFirst(), findAny()
.count() .toArray() GitHub, Twitter :: @pivovarit
Stream.reduce() GitHub, Twitter :: @pivovarit
Collectors .toList(), toMap(), toSet(), toCollection() .minBy(), maxBy() .joining() .partitioningBy() ...and
many others GitHub, Twitter :: @pivovarit
Collectors.toList() GitHub, Twitter :: @pivovarit
Stream in APIs "any string".chars() Files.newDirectoryStream() Random.ints() ... GitHub, Twitter
:: @pivovarit
you want more? GitHub, Twitter :: @pivovarit
github.com/ TouK/ThrowingFunction http://www.javaslang.io/ GitHub, Twitter :: @pivovarit
Thank You! GitHub, Twitter :: @pivovarit
REFERENCES: -"MONADIC JAVA" BY MARIO FUSCO -"WHAT'S WRONG WITH JAVA
8" BY PIERRE-YVES SAUMONT -WWW.ORACLE.COM -"A FISTFUL OF MONADS" - LEARN YOU A HASKELL FOR GREAT GOOD