LT at React.js meetup #2 http://reactjs-meetup.connpass.com/event/19504/

1. Our wish to
Flowtype
@teppeis
React.js meetup #2
Sep 8, 2015

2. Hello!
• Teppei Sato, @teppeis
• Cybozu, Inc. / kintone
• Closure Compiler / TypeScript / Flowtype

3. MUST BUY!

5. I've talked
"Flowtype Introduction"
twice…

8. Flowtype is awesome!

9. Strong type inference

10. React.js integration

11. Check propTypes statically

12. Flowtype is NOT a language

13. Just a type checker (now :))
$ jstransform --strip-types
• Just strip types!

14. Less original syntax

15. Less original syntax
// type cast in Flowtype
var strOrNull = (null: ?string);
// type cast in TypeScript
var strOrNull = <string> null;
• Only type annotation with ":"
• ECMAScript standard friendly

16. Fast! Fast! Fast!

17. Many Facebook repos
using Flowtype
are published

18. Our Facebook made it!

20. after

22. Why?

23. d.ts is not supported yet

26. Not friendly with npm

33. Incomplete documentation
Many pitfalls…

34. Hard to contribute…

36. I wait eagerly Flowtype!

37. Thanks!