Facebook Launches Flow, Static Type Checker for JavaScript

#1

Post by davemo » Tue, Nov 18, 2014, 6:03 PM UTC

Facebook Launches Flow, Static Type Checker for JavaScript
code.prod.facebook.com

Re: Facebook Launches Flow, Static Type Checker for JavaScript

#2

Post by UnixHakr » Tue, Nov 18, 2014, 6:24 PM UTC

Very nice. I wonder how hard this would be to throw into Jasmine/QUnit type scenarios.

Re: Facebook Launches Flow, Static Type Checker for JavaScript

#3

Post by kaonashi » Tue, Nov 18, 2014, 6:25 PM UTC

This is what I wished Typescript was.

Looks really handy.

Re: Facebook Launches Flow, Static Type Checker for JavaScript

#4

Post by antoinelyset » Tue, Nov 18, 2014, 6:28 PM UTC

Flow seems to be close to a true application of type theory and is written in OCaml. Well done Facebook.

Re: Facebook Launches Flow, Static Type Checker for JavaScript

#5

Post by davemo » Tue, Nov 18, 2014, 6:29 PM UTC

If you are interested in learning more about Flow check out the docs [1] and github repo [2].

[1] - http://flowtype.org/

[2] - https://github.com/facebook/flow

Re: Facebook Launches Flow, Static Type Checker for JavaScript

#6

Post by elwell » Tue, Nov 18, 2014, 6:30 PM UTC

Is the type syntax friendly with CoffeeScript?

Re: Facebook Launches Flow, Static Type Checker for JavaScript

#7

Post by avik » Tue, Nov 18, 2014, 6:33 PM UTC

Hi, I'm Avik Chaudhuri, I'm one of the authors of Flow, and I'll be happy to answer questions.

Re: Facebook Launches Flow, Static Type Checker for JavaScript

#8

Post by MrBuddyCasino » Tue, Nov 18, 2014, 6:35 PM UTC

That is quite impressive. No type annotations needed, and control flow is taken intro consideration (hence the name I guess).

If I am not mistaken, this tech could be used to build IDEs roughly similar to whats available for Java, couldn't it?

Re: Facebook Launches Flow, Static Type Checker for JavaScript

#9

Post by jenius » Tue, Nov 18, 2014, 6:35 PM UTC

I know it's very early, but just curious if anyone is working on a node binding for this, or if one exists already? Would love to try it out in our stack, but it would require a javascript interface.

Re: Facebook Launches Flow, Static Type Checker for JavaScript

#10

Post by drapper » Tue, Nov 18, 2014, 6:38 PM UTC

How this compares to TypeScript? At the quick glance I noted:

- more powerful type system (union types, hurray)

- support for JSX

- no windows binaries

- supports more of ES6 stuff

- ...but has no support for modules yet

- no generics (??)

How about performance? and workflow? Didn't yet find this: does it use a normal "write then compile" model like TS or has something like Hack (if I'm not mistaken it has a daemon running in the background, checking the code as you write it).

Wonder why FB decided to roll this on instead of using TS.