PureScript.tw Meetup 2: Tutorial 2

Range: Ch6 of the book PureScript by Example

Transcript

1. PureScript Tutorial 2 Ray Shih
2. Chapter 6~ See how far we can go
3. Chapter 6: Type Classes • Similar to Java interface • Show • Monoid, Foldable -> foldMap • Functor • Function constraint • Multi Parameter Type Classes • Nullary Type Class • Superclass
4. The Class & The Instance
5. Instance Dependencies
6. Common type classes
7. Semigroup, Monoid
8. Foldable
9. Functor
10. Function is a Functor!!! What?
11. Multi Parameter type class
12. Nullary type class
13. Congratulation! That’s all!
14. Congratulation! That’s all…. the syntax you need (almost)
15. Challenge! • Try to create a function `printf` which can print out arbitrary number of arguments • printf “Hello” “World” • printf “a = “ 3 • printf a “ + “ b “ = “ (a + b)
16. Chapter 7: Applicative Validation • Control.Apply, lift3 on Maybe • type class Apply • type class Applicative • Maybe -> Either: withError • combineList • purescript-validation (skip) • Traversable Functor • Parallelism
17. Control.Apply
18. type class Apply
19. instance applyMaybe
20. type class Applicative
21. Revisit lift3
22. Maybe -> Either withError
23. withError example
24. combineList
25. Traversable Functor
26. Parallelism
27. Chapter 8: The Eff Monad • Do notation revisited • XML traverse • The Monad Type Class • Monad Law (skip) • Folding With Monads • Monads and Applicative • Eff Monad
28. Do notation
29. XML traverse
30. The Monad Type Class
31. Monad instances
32. What `do` really do?
33. Reveal the XML parsing example
34. Folding with Monads
35. Folding with Monad example
36. FoldM exercise • (Medium) Write a function sums which uses foldM to determine all possible totals that could be made using a set of coins. The coins will be specified as an array which contains the value of each coin. Your function should have the following result.
37. Monads and Applicatives • Of course, Monad is a Applicative • But Monad is more than Applicative
38. Eff Monad
39. The type of Eff
40. Fine-Grained Effects
41. Next? • Frontend Pux? • Backend? • React Native? • Chapter 11: Monadic Adventures? • Lenses? • PureScript 24 days?