Downloaded 64 times
![FUNCTIONAL PROGRAMMING ESSENTIALS @KELLEYROBINSON sealed abstract class List[+A]
case class Cons[A](head: A, tail: List[A]) extends List[A]
case object Null extends List[Nothing]](https://image.slidesharecdn.com/functionalprogrammingessentials-170418164948/75/Functional-Programming-Essentials-41-2048.jpg)
![FUNCTIONAL PROGRAMMING ESSENTIALS @KELLEYROBINSON def listFunction(list: List[Int]) =
list match {
case Cons(x, xs) => // ... something that uses x and xs...
case Null => // ... something that can’t use x and xs...
}](https://image.slidesharecdn.com/functionalprogrammingessentials-170418164948/75/Functional-Programming-Essentials-42-2048.jpg)
![FUNCTIONAL PROGRAMMING ESSENTIALS @KELLEYROBINSON def length(l: List[Int]): Int =
l match {
case Cons(x, xs) => 1 + length(xs)
case Null => 0
}](https://image.slidesharecdn.com/functionalprogrammingessentials-170418164948/75/Functional-Programming-Essentials-43-2048.jpg)
![FUNCTIONAL PROGRAMMING ESSENTIALS @KELLEYROBINSON def sum(l: List[Int]): Int =
l match {
case Cons(x, xs) => x + sum(xs)
case Null => 0
}](https://image.slidesharecdn.com/functionalprogrammingessentials-170418164948/75/Functional-Programming-Essentials-44-2048.jpg)
![FUNCTIONAL PROGRAMMING ESSENTIALS @KELLEYROBINSON def product(l: List[Int]): Int =
l match {
case Cons(x, xs) => x * product(xs)
case Null => 1
}](https://image.slidesharecdn.com/functionalprogrammingessentials-170418164948/75/Functional-Programming-Essentials-45-2048.jpg)
 => B, d: B, xs: List[A]): B =
xs match {
case Cons(y, ys) => f(y, list(f,d,ys))
case Null => d
}](https://image.slidesharecdn.com/functionalprogrammingessentials-170418164948/75/Functional-Programming-Essentials-46-2048.jpg)
 => B, d: B, xs: List[A]): B def length ... = list((_, b) => 1 + b, 0, xs)
def sum ... = list((a, b) => a + b, 0, xs) def product ... = list((a, b) => a * b, 1, xs)](https://image.slidesharecdn.com/functionalprogrammingessentials-170418164948/75/Functional-Programming-Essentials-47-2048.jpg)
Functional Programming Essentials
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- 4. “Standardized” Ladder of FunctionalProgramming really FUNCTIONAL PROGRAMMING ESSENTIALS @KELLEYROBINSON
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- 7. FUNCTIONAL PROGRAMMING ESSENTIALS@KELLEYROBINSON Essentials Why this matters FP In Scala Origins
- 8. FUNCTIONAL PROGRAMMING ESSENTIALS@KELLEYROBINSON Essentials Why this matters FP In Scala Origins
- 9. Origins Paradigms FUNCTIONAL PROGRAMMING ESSENTIALS@KELLEYROBINSON
- 10. How did weget here? FUNCTIONAL PROGRAMMING ESSENTIALS @KELLEYROBINSON Origins
- 11. FUNCTIONAL PROGRAMMING ESSENTIALS@KELLEYROBINSON “..in the same way that music is not a set of instruments, functional programming is not a set of abstractions that we need to learn and memorize.” - José Calderón Origins
- 12. The Lambda Calculus AlonzoChurch (1930s) @KELLEYROBINSONFUNCTIONAL PROGRAMMING ESSENTIALS Origins
- 13. FUNCTIONAL PROGRAMMING ESSENTIALS@KELLEYROBINSON λx.x+1 variable function application expression Origins
- 14. FUNCTIONAL PROGRAMMING ESSENTIALS@KELLEYROBINSON λx.x+1 scala> { x: Int => x + 1 } res1: Int => Int = <function1> Origins
- 15. The Lambda Calculus AlonzoChurch (1930s) Theoretical foundation Pure functions - no state Not a programming language @KELLEYROBINSONFUNCTIONAL PROGRAMMING ESSENTIALS Origins
- 16. FUNCTIONAL PROGRAMMING ESSENTIALS@KELLEYROBINSON
- 17. “Modern functional languages canbe thought of as (nontrivial) embellishments of the lambda calculus” - Paul Hudak (1989)
- 18. Fortran John Backus (1954) FUNCTIONALPROGRAMMING ESSENTIALS @KELLEYROBINSON Origins
- 19. Logic Theory Machine Newelland Simon (1956) FUNCTIONAL PROGRAMMING ESSENTIALS @KELLEYROBINSON Origins
- 20. Logic Theory Machine Newelland Simon (1956) IPL (Information Processing Language) List processing Recursion FUNCTIONAL PROGRAMMING ESSENTIALS @KELLEYROBINSON Origins
- 21. Lisp John McCarthy (1958) FUNCTIONALPROGRAMMING ESSENTIALS @KELLEYROBINSON Origins
- 22. Functional abstraction Evolution of FunctionalProgramming An Early History Higher level languages List processing & recursion Lisp popularizes paradigm FUNCTIONAL PROGRAMMING ESSENTIALS @KELLEYROBINSON 1930s 1950s Origins
- 23. Paradigms Revisited FUNCTIONAL PROGRAMMING ESSENTIALS@KELLEYROBINSON Origins
- 24. FUNCTIONAL PROGRAMMING ESSENTIALS@KELLEYROBINSON Essentials Why this matters FP In Scala Origins
- 25. Recursive Programming Techniques W.H. Burge (1975) FUNCTIONALPROGRAMMING ESSENTIALS @KELLEYROBINSON Essentials
- 26. This was before… PolymorphicType Inference Algebraic Data types Lazy languages Category-theoretic terminology Introduction: Burge School of Functional Programming FUNCTIONAL PROGRAMMING ESSENTIALS @KELLEYROBINSON W.H. Burge (1975) Essentials
- 27. FUNCTIONAL PROGRAMMING ESSENTIALS@KELLEYROBINSON Expressions Expressions Expressions Expressions Expressions Essentials
- 28. FUNCTIONAL PROGRAMMING ESSENTIALS@KELLEYROBINSON 3x2 + y3x2 + y Essentials
- 29. FUNCTIONAL PROGRAMMING ESSENTIALS@KELLEYROBINSON + (* (3, square(x)), y) 3x2 + y operators operands Essentials
- 30. FUNCTIONAL PROGRAMMING ESSENTIALS@KELLEYROBINSON + (* (3, square(2)), 1) for x = 2, y = 1 operators operands Essentials
- 31. FUNCTIONAL PROGRAMMING ESSENTIALS@KELLEYROBINSON + (* (3, 4), 1) operators operands for x = 2, y = 1 Essentials
- 32. FUNCTIONAL PROGRAMMING ESSENTIALS@KELLEYROBINSON + (12, 1) operators operands for x = 2, y = 1 Essentials
- 33. FUNCTIONAL PROGRAMMING ESSENTIALS@KELLEYROBINSON 13 for x = 2, y = 1 Essentials
- 34. Side Effects Changes outsideof function scope Modifies state Not predictable FUNCTIONAL PROGRAMMING ESSENTIALS @KELLEYROBINSON Essentials
- 35. Expressions Instead of statements Related: Purefunctions Immutable data FUNCTIONAL PROGRAMMING ESSENTIALS @KELLEYROBINSON Essentials
- 36. Referential transparency An expression canbe replaced by its value without changing the program behavior FUNCTIONAL PROGRAMMING ESSENTIALS @KELLEYROBINSON Essentials
- 37. Immutable data Avoid modifyingstate FUNCTIONAL PROGRAMMING ESSENTIALS @KELLEYROBINSON Essentials
- 38. Expressions The programmer benefits Understanding Predictability Unittesting FUNCTIONAL PROGRAMMING ESSENTIALS @KELLEYROBINSON Essentials
- 39. Data Structures Constructing andDeconstructing FUNCTIONAL PROGRAMMING ESSENTIALS @KELLEYROBINSON Essentials
- 40. Data Structures Constructing andDeconstructing 1. How do you make the data? 2. How do you take it apart? FUNCTIONAL PROGRAMMING ESSENTIALS @KELLEYROBINSON Essentials
- 41. FUNCTIONAL PROGRAMMING ESSENTIALS@KELLEYROBINSON sealed abstract class List[+A] case class Cons[A](head: A, tail: List[A]) extends List[A] case object Null extends List[Nothing]
- 42. FUNCTIONAL PROGRAMMING ESSENTIALS@KELLEYROBINSON def listFunction(list: List[Int]) = list match { case Cons(x, xs) => // ... something that uses x and xs... case Null => // ... something that can’t use x and xs... }
- 43. FUNCTIONAL PROGRAMMING ESSENTIALS@KELLEYROBINSON def length(l: List[Int]): Int = l match { case Cons(x, xs) => 1 + length(xs) case Null => 0 }
- 44. FUNCTIONAL PROGRAMMING ESSENTIALS@KELLEYROBINSON def sum(l: List[Int]): Int = l match { case Cons(x, xs) => x + sum(xs) case Null => 0 }
- 45. FUNCTIONAL PROGRAMMING ESSENTIALS@KELLEYROBINSON def product(l: List[Int]): Int = l match { case Cons(x, xs) => x * product(xs) case Null => 1 }
- 46. FUNCTIONAL PROGRAMMING ESSENTIALS@KELLEYROBINSON def list[A, B](f: (A,B) => B, d: B, xs: List[A]): B = xs match { case Cons(y, ys) => f(y, list(f,d,ys)) case Null => d }
- 47. FUNCTIONAL PROGRAMMING ESSENTIALS@KELLEYROBINSON def list[A, B](f: (A,B) => B, d: B, xs: List[A]): B def length ... = list((_, b) => 1 + b, 0, xs) def sum ... = list((a, b) => a + b, 0, xs) def product ... = list((a, b) => a * b, 1, xs)
- 48. Recursive Programming Techniques W.H. Burge (1975) Expressions Datastructures FUNCTIONAL PROGRAMMING ESSENTIALS @KELLEYROBINSON Essentials
- 49. FUNCTIONAL PROGRAMMING ESSENTIALS@KELLEYROBINSON
- 50. FUNCTIONAL PROGRAMMING ESSENTIALS@KELLEYROBINSON Essentials Why this matters FP In Scala Origins
- 51. “Standardized” Ladder of FunctionalProgramming really FUNCTIONAL PROGRAMMING ESSENTIALS @KELLEYROBINSON
- 52. “Modern” Functional Programming is clutteredwith jargon FUNCTIONAL PROGRAMMING ESSENTIALS @KELLEYROBINSON Why this matters
- 53. FUNCTIONAL PROGRAMMING ESSENTIALS@KELLEYROBINSON
- 54. “Jargon comes withan inherent cost. It needs to earn its place. (And it often does: jargon is necessary to discuss complex and domain- specific ideas.)” - Bonnie Eisenman FUNCTIONAL PROGRAMMING ESSENTIALS @KELLEYROBINSON@KELLEYROBINSON Why this matters
- 56. “It is alsoa striking demonstration of the fact that even definitions of very high quality are often inadequate as sources of information on usage.”
- 57. Vocabulary and context arenecessary for understanding
- 58. Ladder of Functional Programming really “Standardized”**Updated!🙄** FUNCTIONALPROGRAMMING ESSENTIALS @KELLEYROBINSON
- 59. Profunctor what? FUNCTIONAL PROGRAMMINGESSENTIALS @KELLEYROBINSON Why this matters
- 60. FUNCTIONAL PROGRAMMING ESSENTIALS@KELLEYROBINSON “It may be fun to brag about knowing how to use "embedded DSL with combinators," but is that really the best thing to help your startup succeed?” - Hacker News Why this matters
- 61. FUNCTIONAL PROGRAMMING ESSENTIALS@KELLEYROBINSON Jargon is alienating Why this matters
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- 63. FUNCTIONAL PROGRAMMING ESSENTIALS@KELLEYROBINSON Essentials Why this matters FP In Scala Origins
- 64. FUNCTIONAL PROGRAMMING ESSENTIALS@KELLEYROBINSON 🙅 FP In Scala
- 65. FUNCTIONAL PROGRAMMING ESSENTIALS@KELLEYROBINSON Storing data val var Iterating map for loop pattern matching procedural statements Deconstructing data preferred possible FP In Scala
- 66. What about…? Cats…Scalaz…FREE MONADS!? Basicsare built into Scala (think `map`, `fold`) Libraries have other syntactic sugar FUNCTIONAL PROGRAMMING ESSENTIALS @KELLEYROBINSON FP In Scala
- 67. • Have fun •Promote understanding • Be kind @KELLEYROBINSONFUNCTIONAL PROGRAMMING ESSENTIALS
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- 69. FUNCTIONAL PROGRAMMING ESSENTIALS Specialthanks to • Sharethrough • José Calderón • Heather Miller • Bonnie Eisenman Resources • Mentioned in this talk: • Bonnie Eisenman on Scala Jargon • José Calderón's Burge School of Functional Programming • Conception, Evolution, and Application of Functional Programming Languages • Original LambdaConf ladder and Updated LambdaConf ladder • Vocabulary Processes • Further Reading & Watching: • Functional programming • Lambda calculus • John McCarthy - History of Lisp • Lambda Calculus - Computerphile • Mark Priestley - New Problems, New Paradigms • John Hughes, Mary Sheeran - Keynote: Why Functional Programming Matters • Vocabulary and Comprehension Research: • The Relationship between Reading Comprehension and Vocabulary Knowledge • The Relationship between Vocabulary Size and Reading Comprehension • Vocabulary and Word Study to Increase Comprehension in Content Areas • Why Vocabulary Instruction Matters • Effects of long-term vocabulary instruction on reading comprehension @KELLEYROBINSON
- 70. @KELLEYROBINSONFUNCTIONAL PROGRAMMING ESSENTIALSFUNCTIONALPROGRAMMING ESSENTIALS Photography credits • Opening image • Solving imaginary scaling issues • Paradigms • Orchestra • Alonzo Church • Philip Wadler • Glitter • Fortran • Chess • A Lisp machine in the MIT Museum • 1975 SNL cast • Side effects • Escher print • Legos • Jargon • Child reading • University • The thinker • Jargon is alienating • Cat typing @KELLEYROBINSON