Little machines that eat strings

A talk about regular expressions and computer science presented at SF dot RB

Transcript

1. Little machines that eat strings
2. I am @samphippen on all the internets
3. Computer Science
4. I ❤❤ Computer Science
5. But not the way it’s taught
7. CS (mostly) won’t make you better at Rails
8. CS (mostly) won’t make you better at Node
9. CS (mostly) won’t make you better at Browsers
10. But it’s super interesting
11. It’s like art for programmers
12. I’m gonna teach you a little computer science
14. Regular Expressions
15. In Ruby
16. >> /wtf/
17. >> /wtf/ === "abc"
18. >> /wtf/ === "abc" => false
19. >> /wtf/ === "wtf" => true
20. >> /wtf/ === "hiwtf" => true
21. >> /wtf/ === "hiwtflol" => true
22. So how does it regex?
23. Let’s introduce a model
24. Let’s say we don’t speak english
25. Let’s say we have a different alphabet
26. There are only two characters
27. Regular Expressions
28. >> / / === “ ” => true
29. >> / / === “ ” => false
30. >> / / === “ ” => false
31. >> / / === “ ” => true
32. >> / / === “ ” => true
33. >> / / === “ ” => true
34. This implies regular expressions have state
35. Let’s introduce a model
36. Regular Expressions
38. Machines have a starting state
39. / /
40. / /
41. Regexp.new(“”)
42. Regexp.new(“”)
43. / /
44. Remember earlier when I said they have state?
45. / /
48. Starting state Accepting state
49. This is called a “deterministic finite automata”
50. This model of Regex was extremely helpful to my learning
51. It’s a different way of thinking about regular expressions
52. To me, that’s what CS is
53. A series of techniques for thinking about computer differently
54. Thanks @samphippen sphippen@do.co