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
   

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2. @GopalAkshintala
   - Some Manager (Not Mine!)
   FP is cool , coz it’s
   complex enough to make
   devs feel like they are
   doing something smart!
   

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3. @GopalAkshintala
   

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4. Dev
   Holy
   Wars
   @GopalAkshintala
   

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5. IDE Theme
   Light
   Vs
   Dark
   @GopalAkshintala
   

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6. Eclipse
   Vs
   Intellij
   @GopalAkshintala
   

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7. OOP Vs FP ?
   @GopalAkshintala
   

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8. @GopalAkshintala
   Immutability
   Referential Transparency
   Side-effects @ Boundaries
   FP Principles
   …………………………………………………
   …………………………………………………
   OOP Principles
   

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9. Imperative
   Vs
   Declarative
   JavaDev
   @GopalAkshintala
   

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10. Imperative
    Code
    -
    -
    -
    Imperative
    @GopalAkshintala
    

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11. Let’s Concatenate
    last names in a
    team with a
    delimiter
    lastName1 lastName2 lastName2
    @GopalAkshintala
    Team Building!
    

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12. @GopalAkshintala
    What about
    Corner cases?
    

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13. @GopalAkshintala
    lastName1 lastName2 lastName2
    
    

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14. @GopalAkshintala
    

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15. @GopalAkshintala
    Imperative Declarative
    

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16. @GopalAkshintala
    

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17. @GopalAkshintala
    Imperative Declarative
    

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18. @GopalAkshintala
    Imperative Declarative
    

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19. @GopalAkshintala
    Imperative Declarative
    

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20. @GopalAkshintala
    

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21. @GopalAkshintala
    

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22. Declarative
    Imperative
    Code
    -
    -
    -
    Imperative
    Vs
    Declarative
    @GopalAkshintala
    

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23. The FP part
    in Java
    The
    Java
    @GopalAkshintala
    

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24. How to Concatenate
    Last names in
    Parallel?
    @GopalAkshintala
    

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25. @GopalAkshintala
    

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26. How-to-dos What-to-dos
    Looping through
    the list
    Aggregating the
    results
    Validating the
    names
    Extracting last
    names
    @GopalAkshintala
    

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27. @GopalAkshintala
    

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28. The
    Context:Core
    Philosophy
    Do
    Things differently
    without
    doing
    Different things!
    @GopalAkshintala
    

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29. Stream
    Busted
    Stream
    Monad
    @GopalAkshintala
    

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30. @GopalAkshintala
    Reading about
    Functors, Monads, Applicatives !
    Kotlin Functors,
    Applicatives, And Monads
    in Pictures (3 parts)
    @Aballano
    

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31. Source
    MayBe Monad
    Context
    Nothing
    Value
    @GopalAkshintala
    

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32. Source @GopalAkshintala
    

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33. Source @GopalAkshintala
    

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34. Source @GopalAkshintala
    

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35. Source @GopalAkshintala
    f(g(h(x)))
    

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36. Monad Composability
    @GopalAkshintala
    

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37. @GopalAkshintala
    Monad Composability
    

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38. Are Monads used in
    Enterprise
    Software?
    @GopalAkshintala
    

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39. Vader
    @GopalAkshintala
    

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40. REST
    APIs
    @GopalAkshintala
    

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41. REST
    Payload
    @GopalAkshintala
    

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42. Simple Data
    Validations
    Nested
    Validations
    Stateful
    Validations
    @GopalAkshintala
    

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43. The
    Batch
    Validation
    Framework
    @GopalAkshintala
    

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44. Valid/Invalid
    @GopalAkshintala
    

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45. • Configure the order of Validations
    • Cross-Share Common & Nested
    Validations
    • Fail-Fast or Error-Accumulation
    • Partial failures
    Framework
    Requirements
    @GopalAkshintala
    

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46. @GopalAkshintala
    Validation layer
    Service layer
    DB layer
    Aggregated Response
    

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47. • Accommodate a century validations
    • Unit testability
    • No compromise on Performance
    Framework
    Meta
    Requirements
    @GopalAkshintala
    

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48. @GopalAkshintala
    

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49. One Egg
    One Validation
    Many Eggs
    One Validation
    @GopalAkshintala
    

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50. Many Eggs
    Many Validations
    !
    @GopalAkshintala
    

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51. Chaos
    @GopalAkshintala
    

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52. Chain of Responsibility
    @GopalAkshintala
    Is FP the Best Fit?
    

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53. @GopalAkshintala
    2D Problem
    Eggs
    Validations
    

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54. Making of a
    Extensible Machine
    @GopalAkshintala
    Validations Configuration Orchestration
    (What-to-do) (How-to-do) (How-to-do)
    

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55. Immutable
    Eggs
    @GopalAkshintala
    

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56. @GopalAkshintala
    Heterogeneous
    DataTypes in pipeline
    

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57. Uniform DataTypes
    with Monad Boxes
    @GopalAkshintala
    

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58. Either Monad
    Egg
    Validation Failure
    Context
    io.vavr.control.Either
    @GopalAkshintala
    Left Right
    

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59. Standardize
    Validations
    @GopalAkshintala
    

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60. @GopalAkshintala
    static boolean validate1Simple(Map badEggFailureBucketMap, int eggIndex,
    
    Iterator iterator, Egg eggToBeValidated) {
    
    if (!simpleOperation1(eggToBeValidated)) {
    
    iterator.remove();
    
    badEggFailureBucketMap.put(eggIndex, NO_EGG_TO_VALIDATE_1);
    
    return false;
    
    }
    
    return true;
    
    }
    static final Validator validate1Simple = validatedEgg "-> validatedEgg
    
    .filter(Operations"::simpleOperation1)
    
    .getOrElse(() "-> Either.left(NO_EGG_TO_VALIDATE_1));
    validate1Simple
    

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61. @GopalAkshintala
    @FunctionalInterface
    
    public interface Validator
    
    extends Function1, Either> {
    
    }
    Validator
    

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62. @GopalAkshintala
    private static boolean validate2Throwable(Map badEggFailureBucketMap, int eggIndex,
    Iterator 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 validate2Throwable = validatedEgg "-> validatedEgg
    
    .filterOrElse(Operations"::throwableOperation2, ignore "-> TOO_LATE_TO_HATCH_2);
    validate2Throwable
    

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63. @GopalAkshintala
    @FunctionalInterface
    
    public interface ThrowableValidator
    
    extends CheckedFunction1, Either> {
    
    }
    ThrowableValidator
    

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64. Configure the order of Validations
    Cross-Share Common & Nested Validations
    Fail-Fast or Error-Accumulation
    Partial failures
    Framework
    How-to-dos
    @GopalAkshintala
    

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65. @GopalAkshintala
    Lift
    ThrowableValidator
    Validator
    

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66. Configure the order of Validations
    Cross-Share Common & Nested Validations
    Fail-Fast or Error-Accumulation
    Partial failures
    Framework
    How-to-dos
    @GopalAkshintala
    

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67. @GopalAkshintala
    Lift
    childValidation: Validator
    ParentValidation: Validator
    

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68. @GopalAkshintala
    Lift
    Validator
    Validator
    Validator
    Validator
    
    
    

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69. Configure the order of Validations
    Cross-Share Common & Nested Validations
    Fail-Fast or Error-Accumulation
    Partial failures
    Framework
    How-to-dos
    @GopalAkshintala
    

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70. Transformation
    map
    flatMap
    filter
    Aggregation
    reduce
    collect
    groupBy
    zip,unzip
    foldLeft,foldRight
    scanLeft,scanRight
    @GopalAkshintala
    Dozen FP Operations for
    Daily Programming
    

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71. Configure the order of Validations
    Cross-Share Common & Nested Validations
    Fail-Fast or Error-Accumulation
    Partial failures
    Framework
    How-to-dos
    @GopalAkshintala
    

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72. Scalability?
    

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73. What about
    Complexity?
    @GopalAkshintala
    

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74. FP is NOT Complex
    It fights
    Cognitive-Complexity
    @GopalAkshintala
    

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75. @GopalAkshintala
    Min.
    Cognitive-Complexity
    Same
    Time-Complexity
    

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76. Railway-Oriented
    Programming
    Scott Wlaschin
    @GopalAkshintala
    

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77. @GopalAkshintala
    bit.ly/imp-vs-dec
    bit.ly/ro-validation
    bit.ly/fcwfp-slides
    { }
    

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78. @GopalAkshintala
    

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79. @GopalAkshintala
    gopal.akshintala@gmail.com
    

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80. @GopalAkshintala
    

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