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Functional programming in scala
1. The document discusses functional programming in Scala, focusing on why FP is useful, its core concepts, and tools like for-comprehensions, Try and Either. 2. It explains key FP concepts like pure functions, referential transparency, and how Scala supports both functional and imperative styles. 3. Functional programming enables testability, reusability, parallelism and comprehension through immutable data and higher-order functions. The document also covers tools like for-comprehensions for working with collections and Try/Either for handling errors in a functional way.
Functional programming in scala
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- 2. WHY FP? • FPConcepts • FP “powers” 1 2 3FP IN SCALA: THE BASICS • Mutability vs Immutability • HOFs • Functions = First-class citizens FP TOOLS • For-comprehension (desugaring) • Try & Either ÍNDICE
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- 4. Functional Programming inScala 1.1 FP Concepts: Pure Function A function of type A => B maps every value of type A to exactly one value of type B And does nothing else “Nothing else” = Side effects: Modifying a data structure, setting a field on a object, throwing an exception, printing to the console, reading from or writing to a file 1 WHY FP?
- 5. Functional Programming inScala 1.1 FP Concepts: Referential transparency 1 WHY FP? If you have an expression, this expression is RT if you can evaluate it and then replace this expression with the value that you get A function is pure if f(x) is RT when x is RT
- 6. Functional Programming inScala 1.1 FP Concepts: Scala is not a purely functional language!! 1 WHY FP?
- 7. Functional Programming inScala 1.2 FP “Powers”: Testability 1 WHY FP?
- 8. Functional Programming inScala 1.2 FP “Powers”: Testability 1 WHY FP?
- 9. Functional Programming inScala 1.2 FP “Powers”: Testability 1 WHY FP?
- 10. Functional Programming inScala 1.2 FP “Powers”: Testability 1 WHY FP?
- 11. Functional Programming inScala 1.2 FP “Powers”: Reusability 1 WHY FP?
- 12. Functional Programming inScala 1.2 FP “Powers”: Reusability 1 WHY FP?
- 13. Functional Programming inScala 1.2 FP “Powers”: Reusability 1 WHY FP?
- 14. Functional Programming inScala 1.2 FP “Powers”: Reusability 1 WHY FP?
- 15. Functional Programming inScala 1.2 FP “Powers”: Reusability 1 WHY FP?
- 16. Functional Programming inScala 1.2 FP “Powers”: Parallelizability 1 WHY FP?
- 17. Functional Programming inScala 1.2 FP “Powers”: Comprehension 1 WHY FP?
- 18. FP IN SCALA: THEBASICS2
- 19. Functional Programming inScala 2.1 Mutability vs Immutability 2 FP IN SCALA: THE BASICS
- 20. Functional Programming inScala 2.1 Mutability vs Immutability 2 FP IN SCALA: THE BASICS
- 21. Functional Programming inScala 2.1 Mutability vs Immutability 2 FP IN SCALA: THE BASICS
- 22. Functional Programming inScala 2.1 Mutability vs Immutability 2 FP IN SCALA: THE BASICS All the classes that mix-in this trait should be in this file A is covariant
- 23. Functional Programming inScala 2.1 Mutability vs Immutability 2 FP IN SCALA: THE BASICS Variadic function syntax Tail call annotation
- 24. Functional Programming inScala 2.2 Higher Order Functions 2 FP IN SCALA: THE BASICS
- 25. Functional Programming inScala 2.3 Functions = First-class citizens 2 FP IN SCALA: THE BASICS Method Function
- 26. Functional Programming inScala 2.3 Functions = First-class citizens 2 FP IN SCALA: THE BASICS Function literal Function value
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- 28. Functional Programming inScala 3.1 For-comprehension 3 FP TOOLS
- 29. Functional Programming inScala 3.1 For-comprehension 3 FP TOOLS
- 30. Functional Programming inScala 3.1 For-comprehension 3 FP TOOLS
- 31. Functional Programming inScala 3.1 For-comprehension 3 FP TOOLS
- 32. Functional Programming inScala 3.1 For-comprehension 3 FP TOOLS
- 33. Functional Programming inScala 3.1 For-comprehension 3 FP TOOLS
- 34. Functional Programming inScala 3.1 For-comprehension 3 FP TOOLS flatMap
- 35. Functional Programming inScala 3.1 For-comprehension 3 FP TOOLS http://docs.scala-lang.org/tutorials/FAQ/yield.html
- 36. Functional Programming inScala 3.1 For-comprehension 3 FP TOOLS
- 37. Functional Programming inScala 3.1 For-comprehension 3 FP TOOLS
- 38. Functional Programming inScala 3.1 For-comprehension 3 FP TOOLS
- 39. Functional Programming inScala 3.1 For-comprehension 3 FP TOOLS
- 40. Functional Programming inScala 3.1 For-comprehension 3 FP TOOLS What else?? Monads!!! Future Try Iteratee RDD (warning!) ...
- 41. Functional Programming inScala 3.2 Try & Either 3 FP TOOLS Alternatives to “pure” exceptions Why? 1º. Exceptions break RT 2º. Exceptions are NOT type-safe
- 42. Functional Programming inScala 3.2 Try & Either 3 FP TOOLS
- 43. Functional Programming inScala 3.2 Try & Either 3 FP TOOLS //Awesome Dataviiiiiis code ;)
- 44. Functional Programming inScala 3.2 Try & Either 3 FP TOOLS //Awesome Dataviiiiiis code ;)
- 45. Functional Programming inScala 3.2 Try & Either 3 FP TOOLS
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- 47. Functional Programming inScala Functional way “powers” => Testability, Reusability, Parallelizability, Comprehension Immutability & HOFs For-comprehension => map, flatMap, filter Functional way => Handling exceptions