Dotty hook for compiler-magic Embed function

[matheusds4]

Basically in Vite.js you can import, say, PNGs, and the bundler will decide whether to externalize the resource (e.g. return a URL pointing to an externally-loaded PNG) or to return a data: URL that is embedded in the program (e.g. if the file is too short).

Although, in actual TypeScript this is kind of boring as there is no import.sync() there for inline usage.

The motivation is that resources (as in src/resources) will both, e.g. appear in the Scala.js bundle (so it can accumulate a lot of heavy icon bitmaps (in case they use skeumorphic design and not SVGs (I know, gradients may help, but those may be a little more complex))). and will also be loaded inconditionally.

https://sweaxizone.github.io/newscala/help/manual/embed.html

In Scala I wanted something like an Embed("flower.webp") expression, and also extra syntaxes for other use-cases like embedding resources normally (text or octet stream, at the entire-program-lifetime and at the .class/JAR/.js) as an extra convenience compared to src/resources.

Also, I know, I know; Next.js's default import does blur optimization so that resulting modules aren't URLs but objects containing a regular source and a blurry source (for preview purposes). I don't know if this is important at all, but in any case, there could be another syntax for this in the future...

[matheusds4]

According to AI, it's not possible to implement this without compiler hooks, as re-type-checking a mutated node and then outputing .class files isn't possible.

[matheusds4]

@odersky @nicolasstucki @smarter @liufengyun Sorry for tagging, but I think this feature needs to be at dotty.

[bishabosha]

can you explain why this can't be implemented via an ordinary macro call? for example that could even open a unix domain socket to a known location that the build tool also communicates through?

Or there are post-type checking compiler plugin option that can generate arbitrary code

[matheusds4]

@bishabosha Thank you for replying. Hmm, yeah, if I'm able to generate code after a WebSocket communication inside a macro it'd be fine.

[matheusds4]

I'd like a cross-platform solution rather than Unix sockets, but it seems java.net.http.WebSocket is async... Is there a blocking/sync-version WebSocket impl for use inside macros?

@bishabosha

[bishabosha]

I guess there is wrap in a scala.concurrent.Future and use Await?