This document contains summaries of presentations from Rubyconf X on November 18, 2010. Chelimsky discussed that reducing duplication increases coupling and to only metaprogram when conditions are unknown. Katz recommended short branches in Rails 3 and refactoring tests or code but not both. Matz said Ruby 2.0 will be out by Christmas for embedded Ruby. Opengov discussed making government data openly available through APIs with MongoDB. Patterson discussed optimizing Ruby performance. Chacon demonstrated Git tools like describing commits and creating bundles. DHH talked about Ruby providing guidance not enforcement and being for consenting adults.

1. Rubyconf X
Thursday, November 18, 2010

2. Thursday, November 18, 2010

3. Chelimsky::Dry
Thursday, November 18, 2010

4. Chelimsky::Dry
• every time you reduce duplication you
increase coupling by introducing new
dependencies
Thursday, November 18, 2010

5. Chelimsky::Dry
• every time you reduce duplication you
increase coupling by introducing new
dependencies
• metaprogram only when you really do not
know the conditions
Thursday, November 18, 2010

6. Chelimsky::Dry
• every time you reduce duplication you
increase coupling by introducing new
dependencies
• metaprogram only when you really do not
know the conditions
• DRY.What does it mean?
Thursday, November 18, 2010

7. Chelimsky::Dry
Thursday, November 18, 2010

8. • Does not mean:“don’t type anything twice”
Chelimsky::Dry
Thursday, November 18, 2010

9. Chelimsky::Dry
Thursday, November 18, 2010

10. Chelimsky::Dry
• Every piece of knowledge
Thursday, November 18, 2010

11. Chelimsky::Dry
• Every piece of knowledge
• must have a
Thursday, November 18, 2010

12. Chelimsky::Dry
• Every piece of knowledge
• must have a
• single,
Thursday, November 18, 2010

13. Chelimsky::Dry
• Every piece of knowledge
• must have a
• single,
• unambiguous,
Thursday, November 18, 2010

14. Chelimsky::Dry
• Every piece of knowledge
• must have a
• single,
• unambiguous,
• authoritative representation
Thursday, November 18, 2010

15. Chelimsky::Dry
• Every piece of knowledge
• must have a
• single,
• unambiguous,
• authoritative representation
• within a system
Thursday, November 18, 2010

16. Chelimsky::Dry
Thursday, November 18, 2010

17. Chelimsky::Dry
• before filters for orthogonal stuff:
Thursday, November 18, 2010

18. Chelimsky::Dry
• before filters for orthogonal stuff:
• authentication
Thursday, November 18, 2010

19. Chelimsky::Dry
• before filters for orthogonal stuff:
• authentication
• logging
Thursday, November 18, 2010

20. Chelimsky::Dry
• before filters for orthogonal stuff:
• authentication
• logging
• not for finding records
Thursday, November 18, 2010

21. Katz
• rails3
• short branches (2days)
• change code or tests, not both
• or, refactor up a level
• deprecation isolation (compat module)
• check out tests on the depot app
Thursday, November 18, 2010

22. Matz
Thursday, November 18, 2010

23. Matz
• ruby 2.0
Thursday, November 18, 2010

24. Matz
• ruby 2.0
• by christmas
Thursday, November 18, 2010

25. Matz
• ruby 2.0
• by christmas
• whatever year
Thursday, November 18, 2010

26. Matz
• ruby 2.0
• by christmas
• whatever year
• embedded ruby
Thursday, November 18, 2010

27. opengov
codeforamerica
sunlight fdn
• making gov data openly and freely available
• building apis with mongo db - eric mill, sunlight foundation / labs
• -> json view chrome extension
• sections argument , range arguments in url determine what’s returned
• different calls each map to dup'd data in the mongo db
• each call maps to a whole data structure in mongo
• crowdsourcing (guardian example). Needs a framework
Thursday, November 18, 2010

28. aaron patterson
@tenderlove
Thursday, November 18, 2010

29. aaron patterson
@tenderlove
• zomg
Thursday, November 18, 2010

30. aaron patterson
@tenderlove
• zomg
• rewrote arel
Thursday, November 18, 2010

31. aaron patterson
@tenderlove
• zomg
• rewrote arel
• superficial vs deep refactoring
Thursday, November 18, 2010

32. aaron patterson
@tenderlove
• zomg
• rewrote arel
• superficial vs deep refactoring
• 6 weeks
Thursday, November 18, 2010

33. aaron patterson
@tenderlove
• zomg
• rewrote arel
• superficial vs deep refactoring
• 6 weeks
• working on integ with mongo
Thursday, November 18, 2010

34. aaron patterson
@tenderlove
does ruby scale?
Thursday, November 18, 2010

35. aaron patterson
@tenderlove
• benchmark over time
Thursday, November 18, 2010

36. aaron patterson
@tenderlove
Thursday, November 18, 2010

37. aaron patterson
@tenderlove
• inject is way slower than hash & a map
• Hash.[@list.map{|val| ... }]
Thursday, November 18, 2010

38. aaron patterson
@tenderlove
• inject is way slower than hash & a map
• Hash.[@list.map{|val| ... }]
• class_eval is way faster than define_method
because dm uses a proc activation
Thursday, November 18, 2010

39. aaron patterson
@tenderlove
• inject is way slower than hash & a map
• Hash.[@list.map{|val| ... }]
• class_eval is way faster than define_method
because dm uses a proc activation
• attr_reader way faster than a method
Thursday, November 18, 2010

40. jake scruggs
• Metric_fu
• The great thing about standards is that
there are so many to choose from
• when to fix, when to refactor (flog>60)
• high churn objects desire better test cov
Thursday, November 18, 2010

41. polite programmer’s
guide
• testing private methods?
• monkey-patch. evil or not?
• fail if instance_methods.map.... include?(:mymethod)
• new method v existing
• delegate vertically if you own, horizontally if not
Thursday, November 18, 2010

42. Scott Chacon
github
Thursday, November 18, 2010

43. Scott Chacon
github$ git describe HEAD
Thursday, November 18, 2010

44. Scott Chacon
github$ git describe HEAD
v0.2.4-25-g8a3f93b
Thursday, November 18, 2010

45. Scott Chacon
github$ git describe HEAD
v0.2.4-25-g8a3f93b
$ git describe HEAD@{1.month.ago}
Thursday, November 18, 2010

46. Scott Chacon
github$ git describe HEAD
v0.2.4-25-g8a3f93b
$ git describe HEAD@{1.month.ago}
v0.2.4-6-gf51a8ba
Thursday, November 18, 2010

47. Scott Chacon
github$ git describe HEAD
v0.2.4-25-g8a3f93b
$ git describe HEAD@{1.month.ago}
v0.2.4-6-gf51a8ba
git log --oneline --decorate --graph
Thursday, November 18, 2010

48. Scott Chacon
github$ git describe HEAD
v0.2.4-25-g8a3f93b
$ git describe HEAD@{1.month.ago}
v0.2.4-6-gf51a8ba
git log --oneline --decorate --graph
git bundle create repo.bundle master
Thursday, November 18, 2010

49. Scott Chacon
github$ git describe HEAD
v0.2.4-25-g8a3f93b
$ git describe HEAD@{1.month.ago}
v0.2.4-6-gf51a8ba
git log --oneline --decorate --graph
git bundle create repo.bundle master
git clone repo.bundle -b master repo
Thursday, November 18, 2010

50. Scott Chacon
github$ git describe HEAD
v0.2.4-25-g8a3f93b
$ git describe HEAD@{1.month.ago}
v0.2.4-6-gf51a8ba
git log --oneline --decorate --graph
git bundle create repo.bundle master
git clone repo.bundle -b master repo
git branch --merged
Thursday, November 18, 2010

51. Scott Chacon
github$ git describe HEAD
v0.2.4-25-g8a3f93b
$ git describe HEAD@{1.month.ago}
v0.2.4-6-gf51a8ba
git log --oneline --decorate --graph
git bundle create repo.bundle master
git clone repo.bundle -b master repo
git branch --merged
git branch --no-merged
Thursday, November 18, 2010

52. Scott Chacon
github$ git describe HEAD
v0.2.4-25-g8a3f93b
$ git describe HEAD@{1.month.ago}
v0.2.4-6-gf51a8ba
git log --oneline --decorate --graph
git bundle create repo.bundle master
git clone repo.bundle -b master repo
git branch --merged
git branch --no-merged
git rerere (Reuse Recorded Resolution)
Thursday, November 18, 2010

53. DHH
Thursday, November 18, 2010

54. DHH
Thursday, November 18, 2010

55. DHH
Thursday, November 18, 2010

56. DHH
Thursday, November 18, 2010

57. DHH
monkey-patching
Thursday, November 18, 2010

58. DHH
monkey-patching
freedom-patching
Thursday, November 18, 2010

59. DHH
monkey-patching
freedom-patching
Thursday, November 18, 2010

60. DHH
Thursday, November 18, 2010

61. DHH
ruby is your friend, not your parents
Thursday, November 18, 2010

62. DHH
ruby is your friend, not your parents
ruby - guidance
Thursday, November 18, 2010

63. DHH
ruby is your friend, not your parents
ruby - guidance
java - enforcement
Thursday, November 18, 2010

64. DHH
ruby is for consenting adults
Thursday, November 18, 2010

65. Thursday, November 18, 2010

66. DHH
Thursday, November 18, 2010

67. DHH
BFF
Thursday, November 18, 2010

68. DHH
Thursday, November 18, 2010

69. DHH
Thursday, November 18, 2010

70. Resources
• Video: http://confreaks.net/events/
rubyconf2010
• Matz Keynote: http://www.slideshare.net/
yukihiro_matz/rubyconf-2010-keynote-by-
matz
• Overall: http://zero2railshero.tumblr.com/
post/1592771138/rubyconf-new-orleans-
awesome-twosome
Thursday, November 18, 2010

71. Resources
• Chelimsky: http://blog.davidchelimsky.net/
wp-content/uploads/2010/11/
duplication.pdf
• online sessions: http://
rubyconfirmate.heroku.com/
conference_sessions
• opengov: http://sunlightlabs.com/
Thursday, November 18, 2010

72. • git-tips.heroku.com
• Scott Chacon: bit.ly/classygit must-see introduction
• Speaker’s Videos: http://confreaks.net/events/
rubyconf2010 up in a week or so
• dave thomas: @pragdave keynote: http://
www.slideshare.net/prqgdave/rubyconfx-
keynote
• james edward gray II @jeg2: http://
www.slideshare.net/JamesEdwardGrayII/unblocked
• poisioning rubinius: @brixen http://slidesha.re/
cLdpsc
Thursday, November 18, 2010