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4Developers: Grzegorz Piwowarek- Java Wars VIII: The Function Awakens
The document discusses advanced Java programming concepts, focusing on lambda expressions, the java.util.function package, and the monad design pattern. It highlights functional programming techniques in Java 8, including the use of Optional, Streams, and methods for managing operations on these types. Additionally, it compares imperative and declarative programming styles and offers insights on enhancing readability and reducing boilerplate code.
4Developers: Grzegorz Piwowarek- Java Wars VIII: The Function Awakens
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- 2. GitHub, Twitter ::@pivovarit
- 3. GitHub, Twitter ::@pivovarit VISIONS OF TONDAL.PL
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- 10. lambda expressions GitHub, Twitter:: @pivovarit
- 11. lambda expressions (...) ->statement - Anonymous function GitHub, Twitter :: @pivovarit
- 12. lambda expressions x ->x + 1 GitHub, Twitter :: @pivovarit
- 13. lambda expressions x ->x + 1 GitHub, Twitter :: @pivovarit () -> 42
- 14. lambda expressions x ->x + 1 GitHub, Twitter :: @pivovarit () -> 42 () -> {return 42;}
- 15. lambda expressions x ->x + 1 GitHub, Twitter :: @pivovarit () -> 42 (x, y) -> {} () -> {return 42;}
- 16. lambda expressions x ->x + 1 - No type information GitHub, Twitter :: @pivovarit
- 17. method references GitHub, Twitter:: @pivovarit
- 18. java.util.function GitHub, Twitter ::@pivovarit
- 19. 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
- 20. 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
- 21. 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
- 22. 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
- 23. 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
- 24. MONAD GitHub, Twitter ::@pivovarit
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- 34. ... GitHub, Twitter ::@pivovarit
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- 36. Why bother? : Boilerplate-- Readability++ Complexity-- GitHub,Twitter :: @pivovarit
- 37. Imperative approach GitHub, Twitter:: @pivovarit
- 38. Declarative approach GitHub, Twitter:: @pivovarit
- 39. Generic type: "unit" method: "bind"method: MONAD GitHub, Twitter :: @pivovarit
- 40. Generic type: "unit" method: "bind"method: MONAD GitHub, Twitter :: @pivovarit
- 41. Generic type: "unit" method: "bind"method: MONAD GitHub, Twitter :: @pivovarit
- 42. Generic type: "unit" method: "bind"method: MONAD GitHub, Twitter :: @pivovarit
- 43. GitHub, Twitter ::@pivovarit
- 44. GitHub, Twitter ::@pivovarit
- 45. GitHub, Twitter ::@pivovarit
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- 47. Solution GitHub, Twitter ::@pivovarit
- 48. Monads in Java8 Optional Stream CompletableFuture GitHub, Twitter :: @pivovarit
- 49. Monads in Java8 Optional Stream CompletableFuture GitHub, Twitter :: @pivovarit
- 50. Optional Encapsulation of operations onoptional values GitHub, Twitter :: @pivovarit
- 51. Optional Encapsulation of operations onoptional values GitHub, Twitter :: @pivovarit
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- 54. Optional type: Optional<T> "unit": Optional.ofNullable(),Optional.of() "bind": GitHub, Twitter :: @pivovarit
- 55. Optional type: Optional<T> "unit": Optional.ofNullable(),Optional.of() "bind": Optional.flatMap(), Optional.map() GitHub, Twitter :: @pivovarit
- 56. Filtering an Optional .filter(Predicate<T>) GitHub,Twitter :: @pivovarit
- 57. Unwrapping an Optional .get() .orElse(Tdefault) .orElseGet(Supplier<T>) .orElseThrow(Supplier<Ex>) .ifPresent(Consumer<T>) GitHub, Twitter :: @pivovarit
- 58. GitHub, Twitter ::@pivovarit http://theworryfreelife.com/wp-content/uploads/2015/08/comfort-zone.jpg
- 59. Java 7 style GitHub,Twitter :: @pivovarit
- 60. Java 8 style GitHub,Twitter :: @pivovarit
- 61. Java 7,5 style;) GitHub, Twitter :: @pivovarit
- 62. Java 7,5 style;) GitHub, Twitter :: @pivovarit
- 63. GitHub, Twitter ::@pivovarit
- 64. GitHub, Twitter ::@pivovarit
- 65. Stream Encapsulation of operations onmultiple items GitHub, Twitter :: @pivovarit
- 66. Stream type: Stream<T> "unit": Stream.of(),Arrays.stream(), Collection.stream() "bind": Stream.flatMap() GitHub, Twitter :: @pivovarit
- 67. Stream GitHub, Twitter ::@pivovarit
- 68. Stream GitHub, Twitter ::@pivovarit
- 69. Stream GitHub, Twitter ::@pivovarit
- 70. Imperative vs. Declarative GitHub,Twitter :: @pivovarit
- 71. Imperative vs. Declarative GitHub,Twitter :: @pivovarit
- 72. Stream && Optional GitHub,Twitter :: @pivovarit
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- 75. intermediate operations .map() .flatMap() .filter() .peek() Stream notconsumed: does not print anything GitHub, Twitter :: @pivovarit
- 76. Consuming Stream .forEach(Consumer<T>) .collect() .reduce(BinaryOperator<T>) .allMatch(), anyMatch(),noneMatch() .findFirst(), findAny() .count() .toArray() GitHub, Twitter :: @pivovarit
- 77. Stream.reduce() GitHub, Twitter ::@pivovarit
- 78. Collectors .toList(), toMap(), toSet(),toCollection() .minBy(), maxBy() .joining() .partitioningBy() ...and many others GitHub, Twitter :: @pivovarit
- 79. Collectors.toList() GitHub, Twitter ::@pivovarit
- 80. Stream in APIs "anystring".chars() Files.newDirectoryStream() Random.ints() ... GitHub, Twitter :: @pivovarit
- 81. you want more? GitHub,Twitter :: @pivovarit
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- 83. Thank You! GitHub, Twitter:: @pivovarit
- 84. REFERENCES: -"MONADICJAVA" BY MARIOFUSCO -"WHAT'S WRONG WITH JAVA 8" BY PIERRE-YVES SAUMONT -WWW.ORACLE.COM -"A FISTFUL OF MONADS" - LEARN YOU A HASKELL FOR GREAT GOOD