Function Javascript 101 Class (Abridged)

1. Functional Js Class

3. First Class Functions

16. Exercises

17. Loops

24. Imperative
vs
Declarative

35. Exercises

36. Type Signatures

44. Type Signatures
• Tell you a “ton” about the function
• Very helpful when doing point free
• http://haskell.org/hoogle/
• http://ttic.uchicago.edu/~dreyer/course/
papers/wadler.pdf (theorems for free)
• https://vimeo.com/28069495 (data driven dev)

45. Purity

46. What’s Impure
• Mutations
• References to things outside the function
• Side effects (logging, db, http, ui)
• Given the same argument, it can give
different output

57. Pure Functions
• Portable
• Parallelizable
• Reusable
• Easily tested
• Easy to reason about

58. Partial Application

64. Curried Function
“A function that takes one
argument at a time”

75. Partial Application
• Build new functions
• “Freeze” state
• Make types “line up”
• Composition

76. Exercises

77. Composition

93. Category Theory
“The mathematical theory of function
composition”
*inaccurate definition

97. Exercises

98. Composition
• Build new functions from other functions
• Declarative
• Mathematically backed
• Cornerstone of functional programs

99. Design

105. Review
• Loops
• First class functions
• Declarative vs Imperative
• Type signatures
• Purity
• Partial application
• Composition
• Module Design