Our wish to Flowtype

@teppeis

React.js meetup #2 Sep 8, 2015

Hello!• Teppei Sato, @teppeis

• Cybozu, Inc. / kintone

• Closure Compiler / TypeScript / Flowtype

MUST BUY!

I've talked "Flowtype Introduction"

twice…

Flowtype is awesome!

Strong type inference

React.js integration

Check propTypes statically

Flowtype is NOT a language

Just a type checker (now :))

$ jstransform --strip-types

• Just strip types!

Less original syntax

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

Fast! Fast! Fast!

Many Facebook repos using Flowtype are published

Our Facebook made it!

after

Why?

d.ts is not supported yet

Not friendly with npm

Incomplete documentation Many pitfalls…

Hard to contribute…

I wait eagerly Flowtype!

Thanks!