[lewisl9029]

Great list!

Related to your point on supporting 0-transpilation workflows as a first class citizen, is the fact that Flow was explicitly just type annotations & checking, and aimed to introduce 0 runtime constructs.

This is something Flow did from the beginning and TypeScript eventually established as a non-goal after already implementing several runtime constructs that they can no longer afford to remove for backwards compat [1].

Though interestingly enough, Flow themselves recently announced they're going to start introducing runtime constructs, which is an interesting plot twist [2].

[1] https://github.com/Microsoft/TypeScript/wiki/TypeScript-Desi...

[2] https://medium.com/flow-type/clarity-on-flows-direction-and-...

[laurencerowe]

In another plot twist TypeScript is supporting the Types as Comments TC39 proposal that would provide a true 0-transpilation workflow.

https://devblogs.microsoft.com/typescript/a-proposal-for-typ...