Cool project! Check out my effort to make nim 3 compile to TS, could eventually be useful here

[evelant]

Out of curiosity and to learn more about nim and compilers I started an effort to add typescript output to nimony (nim 3.0). Similar to the js output of nim 2, but fully typed TS. It is far from complete or correct yet, but I thought you might find it interesting.

My eventual goal if I could get it to work well is to write Nim and emit readable TS that could be used in a react native app (or anywhere else that needs js/ts) rather than going the C or wasm route. Not really sure if it's worth pursuing further given improvements in react native binding to C (nitro-modules) and wasm in the browser, but the start of it is there if you're curious.

https://github.com/evelant/nimony/tree/feat/tsgen

[siddarthkay]

Hey hey @evelant : Thanks for the kind words about this project, I appreciate it.

I took a look at tsgen and I like :

• (gentypes_ts.nim) -> A tsType function that maps Nim types to TS types. Our Python binding generator does something similar but less systematically.
  This approach of handling object → interface, enum → const as const + union type, and tuple → TS tuple types is very well-structured and well though out.

• (nim_runtime.ts) -> A small runtime with numeric overflow helpers (addInt32, mulInt64), pointer emulation (RefCell<T>, Ptr<T>), and string conversion.
  This is a nice separation of concerns in the runtime.

• Branded types for distinct -> Using TypeScript's structural typing with Brand<K> to emulate Nim's distinct types at the TS level is very clever. it's a good pattern.

Regarding using this in react-native-nim :

The whole point of react-native-nim is native performance via C.
Nim compiles to C, which becomes a static/shared library linked directly into the app via NitroModules/JSI.
Transpiling Nim to TypeScript would just give us... TypeScript, which is what we're already writing the UI in.
There's no performance benefit.

The C route is the strength. The value proposition of react-native-nim is : write business logic in Nim, get native ARM code (no JS bridge overhead, no GC pauses from the JS engine).
Nim → TS would run in the same JS engine as the React Native app, defeating this purpose.

Very cool compiler engineering none the less, Good job on that :)