Fun Ruby

Functional Programming concepts in Ruby

Transcript

1. Fun Ruby Functional Programming concepts in Ruby
2. Who? Guilherme Carlos 23 Computer Information Systems PUC Campinas @gtcarlos_ gtcarlos
3. Functional Programming?
6. Lambda Calculus 1930s Alonzo Church (Princeton) Lambda Currying Immutability Pure Functions
7. LISP 1959 John McCarthy (MIT) Lambda Calculus applied Symbols Garbage Collector
8. FP in a Nutshell ➔ Anonymous Functions ➔ Higher Order Functions ➔ Immutability ➔ No Side-Effects
9. Ruby is not a functional language! but have some functional traits
10. Anonymous Function
11. Closures
13. ➔ Anonymous Functions (Lambda) ➔ Higher Order Functions ➔ Immutability ➔ No Side-Effects
14. ➔ Accept a function as an argument ➔ Return a function as the return value Higher Order Function
15. Blocks everywhere!
16. Enumerable
17. ➔ Anonymous Functions (Lambda) ➔ Higher Order Functions ➔ Immutability ➔ No Side-Effects
18. Immutability “Much of Ruby, especially its runtime, is much closer to Python's [than Perl's], with the exception of Ruby's mutable strings, which I find an abomination.” - Guido van Rossum (Python creator)
22. Bang!
23. ➔ Anonymous Functions (Lambda) ➔ Higher Order Functions ➔ Immutability ➔ No Side-Effects
24. Pure Functions ➔ The function always evaluates the same result value given the same argument value ➔ Evaluation of the result does not cause any semantically observable side effect or output
27. ➔ Anonymous Functions (Lambda) ➔ Higher Order Functions ➔ Immutability ➔ No Side-Effects
28. Advantages of FP ➔ Best readability ➔ Modularity ➔ Concurrency ➔ Testability
29. Disadvantages of FP ➔ Not suited to every problem ➔ Academic stuff
30. Rolling in the Deep Elixir Clojure Scala
31. Questions?