Umbrella: Library Mode

[cometkim]

This is an umbrella issue to track and discusses the remaining issues to be resolved to achieve "Library Mode"

The "Library Mode" means that the ReScript compiler can be adopted as a first-class tool for building libraries in today's JavaScript ecosystem.

Opened RFCs

• RFC: New GenType for TypeScript #6196
• RFC: New package-spec "dual" #6209
• RFC: @deriving for labeled arguments #6530
• RFC: conditional module FFI #6946

Related changes

• Deprecated es6 and es6-global in favor of esmodule #6709
• Fix unhandled cases for exotic idents #6777

Open discussions

Tell us your story if you've ever provided a JavaScript library based on ReScript (not binding)

[DZakh]

I've written the script to support library mode for rescript-struct. https://github.com/DZakh/rescript-struct/blob/main/packages/prepack/src/Prepack.res
I'll share the problems it solves a little bit later when I have time.

[hellos3b]

Following! The above two issues would prevent the need for a secondary build step (rollup) and make making libraries much simpler.