Papers we love: Elixir edition

Transcript

1. PAPERS WE LOVE ELIXIR EDITION PAPERS WE LOVE ELIXIR EDITION
2. @whatyouhide
8. “You know Yelp? Yeah, but for weed”– me
11. “You know Uber Eats?”– me
13. weedmaps.com/careers
14. ELIXIR functional concurrent fault tolerant
15. The Elixir core team
16. we existing research
17. Formatting code Diffing data structures Property-based testing ⚙
18. FORMATTING CODE
19. Code formatter welcoming to newcomers consistency across teams/orgs/community no style discussions
20. print code with line length limit
21. %{foo: [1, 2, 3], bar: "baz"}
22. %{foo: [1, 2, 3], bar: "baz"} 30
23. %{foo: [1, 2, 3], bar: "baz"} 25
24. %{ foo: [1, 2, 3], bar: "baz" } 25
25. %{ foo: [1, 2, 3], bar: "baz" } 13
26. %{ foo: [ 1, 2, 3 ], bar: "baz" } 13
27. The Design of a Pretty-printing Library John Hughes
28. Documents "text" concat(document1, document2) nest(document, columns)
29. "[" |> concat("1,") |> concat("2,") |> concat("3") |> concat("]") [1, 2, 3]
30. "[" |> line("1,") |> line("2,") |> line("3") |> nest(2) |> line("]") [ 1, 2, 3 ]
31. A Prettier Printer Philip Wadler
32. group( "[" |> concat("1,") |> concat("2,") |> concat("3") |> nest(2) |> concat("]") ) [ 1, 2, 3 ]
33. choose( doc, replace_concat_with_line_break(doc) ) DANGER: STRICT LANGUAGE AHEAD
34. Strictly Pretty Christian Lindig
35. Our documents color(doc, :blue) nest(doc, :cursor) ...
36. DIFFING DATA STRUCTURES
37. 1) test two strings are different (Test) test.ex:6 Assertion with == failed code: assert "hello world!" == "Hello, my world" left: "hello world!" right: "Hello, my world" stacktrace: test.ex:7: (test)
39. An O(ND) Difference Algorithm and Its Variations Eugene W. Myers
40. “Find the shortest edit script to turn a sequence A into a sequence B.” = Find shortest path in a graph
41. O(ND) D is related to how "similar" the two sequences are DNA strand mutation source code changes
42. iex> List.myers_difference([1, 4, 2, 3], [1, 2, 3, 4]) [eq: [1], del: [4], eq: [2, 3], ins: [4]]
43. Now colorize
44. No modifications to the paper this time
45. String Matching with Metric Trees Using an Approximate Distance Ilaria Bartolini, Paolo Ciaccia, Marco Patella
46. PROPERTY-BASED TESTING
47. Shape of input Properties of output + + Randomness = Property-based testing
48. check all list <- list_of(term()) do sorted = sort(list) assert is_list(sorted) assert length(list) == length(sorted) end
49. String.starts_with?(s1 <> s2, s1) String.ends_with?(s1 <> s2, s2) For any strings s1 and s2:
50. Only Erlang tools (with different license)
51. QuickCheck: A Lightweight Tool for Random Testing of Haskell Programs Koen Classen John Hughes
52. all the base ideas are there but it relies too heavily on types
53. data Colour = Red | Blue | Green instance Arbitrary Colour where arbitrary = oneof [return Red, return Blue, return Green]
54. (prop/for-all [v (gen/vector gen/int)] (= (sort v) (sort (sort v)))) Clojure's test.check
55. StreamData check all s1 <- string(), s2 <- string() do assert String.starts_with?(s1 <> s2, s1) assert String.ends_with?(s1 <> s2, s2) end
56. Generators functions that take some random state and return a lazy tree
57. Lazy tree a value plus a "recipe" for shrinking it
58. StreamData.integer() 3 0 2 0 1 0
59. StreamData.integer() 3 0 2 0 1 0
60. map(StreamData.integer(), fn x -> x * 2 end) 3 * 2 0 * 2 2 * 2 0 * 2 1 * 2 0 * 2
61. map(StreamData.integer(), fn x -> x * 2 end) 6 0 4 0 2 0
62. HONORABLE MENTIONS
63. How to make ad-hoc polymorphism less ad hoc Philip Wadler Stephen Blott
64. Recursive functions of symbolic expressions and their computation by machine John McCarthy
65. Advances in record linkage methodology as applied to the 1985 census of Tampa Florida Matthew A. Jaro
66. Iteratee: Teaching an Old Fold New Tricks John W. Lato
67. CONCLUSIONS
68. Existing research is AWESOME
69. Research tends to solve problems in a general/simple/flexible/elegant way
70. HDD Hughes-driven development
71. @whatyouhide