We just landed support for TypeScript in the Hermes parser! (We can already parse Flow.) The rest of the compiler can't handle the annotations yet (that will come later), but tools that need to analyze JS source extremely fast can use the parser. Tweet added by Tzvetan Mikov @tmikov

Tzvetan Mikov

3 years

We just landed support for TypeScript in the Hermes parser! (We can already parse Flow.) The rest of the compiler can't handle the annotations yet (that will come later), but tools that need to analyze JS source extremely fast can use the parser.

Parse TS 'as' expression. · facebook/hermes@d3f4c3f

Summary: TS can use `x as T` to typecast in situations when the type assertion `x` would be unusable due to conflicting with JSX syntax. To support this, we add special cases to t...

github.com

1

5

36

Victor Malov

@vicmalov

3 years

@tmikov It's awesome. But what's the reason of adding TypeScript into Hermes? How it's going to be used? I bet it will no anyhow affect generated code (but would be cool to have beast mode)

1

0

Tzvetan Mikov

@tmikov

3 years

@vicmalov There are benefits to compiling the actual source as written, without involving multiple source transformation tools, packagers, source maps, etc. The parser alone can already be used as a library by tools that need to analyze large mixed codebases quickly.

1

0

2

Replies