feat: export to javascript using scala-js

[rhazn]

What

This PR adds an experimental export to javascript to the parser using Scala-JS. I was playing around with using the parser in a JS context (for parsing in a browser) and saw it is actually reasonably easy to do. This adds overhead and untested code so I am 100% okay with this PR not being merged, I just figured since I already did the work myself I can offer you the result.

Maybe this can serve as a discussion if you are interested in going down this route at all ;).

Demo

If you serve the generated file locally this is a minimal working example html:

<script type="module">
	import {TPTPParser} from "http://localhost:8000/main.js";

	console.log(TPTPParser.annotatedTHF("thf(f, axiom, ![X:$i]: (p @ X))."));
	console.log(TPTPParser.thf("![X:$i]: (p @ X)"));
</script>

That produces these console.logs in which you can see the generated objects for the parsed formulas.

Issues

• The generated JS code is 1.5mb big
• The code is untested
• The compilation might brake at any point in the future, e.g. if you introduce scala only libraries as dependencies

[rhazn]

Ah this sadly seems to auto enable some testing that is not correctly initialized and therefore fails :(. Sorry I did not assume it magically registers tests, I'll have to look into that some time.

[lex-lex]

Thanks! Looks like a cool feature to have it as off-the-shelf as a JS library. Looking forward to see this progress :-)

[rhazn]

I had a small additional look into this and it seems like it would take setting up a Cross-Building (https://www.scala-js.org/doc/project/cross-build.html) project for it to work. The setup I did only builds the JS part (as well as a JAR that only other scala-js projects can consume).

Sadly my sbt knowledge is limited, if I try to follow that guide to the best of my abilities the compiler can not find the scala-js annotations, even with the scalajs-stubs dependency mentioned at the end of the page.

I'll see if I can find the time to look into this a bit more down the line but for now I am out of ideas.