Fight Complexity with Functional Programming

More about this talk can be found here: https://overfullstack.github.io/posts/fight-complexity-with-fp/

Transcript

1. overfullstack.github.io
2. @GopalAkshintala - Some Manager (Not Mine!) FP is cool , coz it’s complex enough to make devs feel like they are doing something smart!
3. @GopalAkshintala
4. Dev Holy Wars @GopalAkshintala
5. IDE Theme Light Vs Dark @GopalAkshintala
6. Eclipse Vs Intellij @GopalAkshintala
7. OOP Vs FP ? @GopalAkshintala
8. @GopalAkshintala Immutability Referential Transparency Side-effects @ Boundaries FP Principles ………………………………………………… ………………………………………………… OOP Principles
9. Imperative Vs Declarative JavaDev @GopalAkshintala
10. Imperative Code - - - Imperative @GopalAkshintala
11. Let’s Concatenate last names in a team with a delimiter lastName1 lastName2 lastName2 @GopalAkshintala Team Building!
12. @GopalAkshintala What about Corner cases?
13. @GopalAkshintala lastName1 lastName2 lastName2
14. @GopalAkshintala
15. @GopalAkshintala Imperative Declarative
16. @GopalAkshintala
17. @GopalAkshintala Imperative Declarative
18. @GopalAkshintala Imperative Declarative
19. @GopalAkshintala Imperative Declarative
20. @GopalAkshintala
21. @GopalAkshintala
22. Declarative Imperative Code - - - Imperative Vs Declarative @GopalAkshintala
23. The FP part in Java The Java @GopalAkshintala
24. How to Concatenate Last names in Parallel? @GopalAkshintala
25. @GopalAkshintala
26. How-to-dos What-to-dos Looping through the list Aggregating the results Validating the names Extracting last names @GopalAkshintala
27. @GopalAkshintala
28. The Context:Core Philosophy Do Things differently without doing Different things! @GopalAkshintala
29. Stream Busted Stream Monad @GopalAkshintala
30. @GopalAkshintala Reading about Functors, Monads, Applicatives ! Kotlin Functors, Applicatives, And Monads in Pictures (3 parts) @Aballano
31. Source MayBe Monad Context Nothing Value @GopalAkshintala
32. Source @GopalAkshintala
33. Source @GopalAkshintala
34. Source @GopalAkshintala
35. Source @GopalAkshintala f(g(h(x)))
36. Monad Composability @GopalAkshintala
37. @GopalAkshintala Monad Composability
38. Are Monads used in Enterprise Software? @GopalAkshintala
39. Vader @GopalAkshintala
40. REST APIs @GopalAkshintala
41. REST Payload @GopalAkshintala
42. Simple Data Validations Nested Validations Stateful Validations @GopalAkshintala
43. The Batch Validation Framework @GopalAkshintala
44. Valid/Invalid @GopalAkshintala
45. • Configure the order of Validations • Cross-Share Common & Nested Validations • Fail-Fast or Error-Accumulation • Partial failures Framework Requirements @GopalAkshintala
46. @GopalAkshintala Validation layer Service layer DB layer Aggregated Response
47. • Accommodate a century validations • Unit testability • No compromise on Performance Framework Meta Requirements @GopalAkshintala
48. @GopalAkshintala
49. One Egg One Validation Many Eggs One Validation @GopalAkshintala
50. Many Eggs Many Validations ! @GopalAkshintala
51. Chaos @GopalAkshintala
52. Chain of Responsibility @GopalAkshintala Is FP the Best Fit?
53. @GopalAkshintala 2D Problem Eggs Validations
54. Making of a Extensible Machine @GopalAkshintala Validations Configuration Orchestration (What-to-do) (How-to-do) (How-to-do)
55. Immutable Eggs @GopalAkshintala
56. @GopalAkshintala Heterogeneous DataTypes in pipeline
57. Uniform DataTypes with Monad Boxes @GopalAkshintala
58. Either Monad Egg Validation Failure Context io.vavr.control.Either @GopalAkshintala Left Right
59. Standardize Validations @GopalAkshintala
60. @GopalAkshintala static boolean validate1Simple(Map<Integer, ValidationFailure> badEggFailureBucketMap, int eggIndex, Iterator<Egg> iterator, Egg eggToBeValidated) { if (!simpleOperation1(eggToBeValidated)) { iterator.remove(); badEggFailureBucketMap.put(eggIndex, NO_EGG_TO_VALIDATE_1); return false; } return true; } static final Validator<ImmutableEgg, ValidationFailure> validate1Simple = validatedEgg "-> validatedEgg .filter(Operations"::simpleOperation1) .getOrElse(() "-> Either.left(NO_EGG_TO_VALIDATE_1)); validate1Simple
61. @GopalAkshintala @FunctionalInterface public interface Validator<ValidatableT, FailureT> extends Function1<Either<FailureT, ValidatableT>, Either<FailureT, ValidatableT">> { } Validator
62. @GopalAkshintala private static boolean validate2Throwable(Map<Integer, ValidationFailure> badEggFailureBucketMap, int eggIndex, Iterator<Egg> iterator, Egg eggToBeValidated) { try { if (!throwableOperation2(eggToBeValidated)) { iterator.remove(); badEggFailureBucketMap.put(eggIndex, TOO_LATE_TO_HATCH_2); return false; } } catch (Exception e) { iterator.remove(); badEggFailureBucketMap.put(eggIndex, ValidationFailure.withErrorMessage(e.getMessage())); return false; } return true; } static final ThrowableValidator<ImmutableEgg, ValidationFailure> validate2Throwable = validatedEgg "-> validatedEgg .filterOrElse(Operations"::throwableOperation2, ignore "-> TOO_LATE_TO_HATCH_2); validate2Throwable
63. @GopalAkshintala @FunctionalInterface public interface ThrowableValidator<ValidatableT, FailureT> extends CheckedFunction1<Either<FailureT, ValidatableT>, Either<FailureT, ?">> { } ThrowableValidator
64. Configure the order of Validations Cross-Share Common & Nested Validations Fail-Fast or Error-Accumulation Partial failures Framework How-to-dos @GopalAkshintala
65. @GopalAkshintala Lift ThrowableValidator<ParentT, FailureT> Validator<ParentT, FailureT>
66. Configure the order of Validations Cross-Share Common & Nested Validations Fail-Fast or Error-Accumulation Partial failures Framework How-to-dos @GopalAkshintala
67. @GopalAkshintala Lift childValidation: Validator<ChildT, FailureT> ParentValidation: Validator<ParentT, FailureT>
68. @GopalAkshintala Lift Validator<Yolk, FailureT> Validator<ChickenEgg, FailureT> Validator<Yolk, FailureT> Validator<DinoEgg, FailureT>
69. Configure the order of Validations Cross-Share Common & Nested Validations Fail-Fast or Error-Accumulation Partial failures Framework How-to-dos @GopalAkshintala
70. Transformation map flatMap filter Aggregation reduce collect groupBy zip,unzip foldLeft,foldRight scanLeft,scanRight @GopalAkshintala Dozen FP Operations for Daily Programming
71. Configure the order of Validations Cross-Share Common & Nested Validations Fail-Fast or Error-Accumulation Partial failures Framework How-to-dos @GopalAkshintala
72. Scalability?
73. What about Complexity? @GopalAkshintala
74. FP is NOT Complex It fights Cognitive-Complexity @GopalAkshintala
75. @GopalAkshintala Min. Cognitive-Complexity Same Time-Complexity
76. Railway-Oriented Programming Scott Wlaschin @GopalAkshintala
77. @GopalAkshintala bit.ly/imp-vs-dec bit.ly/ro-validation bit.ly/fcwfp-slides { }
78. @GopalAkshintala
79. @GopalAkshintala gopal.akshintala@gmail.com
80. @GopalAkshintala