Interestingly, a type system was proposed for JavaScript around 2007 as part of ES4, which was later abandoned [1]. The proposed details in [2] are strikingly s

Interestingly, a type system was proposed for JavaScript around 2007 as part of ES4, which was later abandoned [1]. The proposed details in [2] are strikingly similar to what we've ended up with in Flow and TypeScript. [1] https://en.wikipedia.org/wiki/ECMAScript#4th_Edition_.28abandoned.29 https://en.wikipedia.org/wiki/ECMAScript#4th_Edition_.28aban... [2] https://www.ecma-international.org/activities/Languages/Language%20overview.pdf https://www.ecma-international.org/activities/Languages/Lang...