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Comment by steinuil | Hacker News Reader

This feels a lot like what happened to Hack, which at first was compatible with PHP and could be compiled to it, but later became its own language to better fit FB's needs, and it seems like they're giving OCaml the same treatment here with ReScript.

There was actually some effort being made to keep OCaml tooling compatible with ReasonML (which is supported by dune[0] with no additional configuration) and BuckleScript integration with dune, which was being worked on before this rebrand, so it's kind of sad to see FB going off on their own with ReScript because they don't wanna do the work to upstream the changes they need.

By the way, regular OCaml also has its own JS backend[1] which is of course completely incompatible with BuckleScript.

0: https://dune.build/ 1: https://github.com/ocsigen/js_of_ocaml

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> it's kind of sad to see FB going off on their own with ReScript

ReScript is not a Facebook project. The compiler is licensed by Bloomberg LLP: https://github.com/rescript-lang/rescript-compiler/blob/60a1...

And the syntax is licensed by the ReScript team: https://github.com/rescript-lang/syntax/blob/72d9b7034fc28f3...

The ReScript team is comprised of both Facebook and folks outside Facebook.

IMO this isn't about whether ReScript wants to upstream their changes, it's a combination of things:

- Reason+BuckleScript was confusing at best, having two websites and different release schedules.

- Reason's goal is to be a 100% mapped syntax for OCaml. This does not mesh well with the goal of producing readable JS, so ReScript will probably end up as a subset of OCaml features.

- Reason syntax changes apparently caused grief when applied to BuckleScript. This one was never very clear, but regardless now that the syntax is in-house the ReScript team can be more responsive with it.

The problem with this transition is that it was dropped on the community in an unfinished state and BuckleScript was retired completely. The goals of the change are, I think, mostly reasonable.

I have no skin in the game w.r.t to OCaml/Reason/etc. I do wish compile-to-JS languages would give up on the readable Javascript thing. I think ClojureScript nailed it with their reliance on Google Closure's aggressive optimization mode __because__ it produces obfuscated, highly optimized output.

Purescript also shares this goal, and it is a bummer, performance-wise, in older browsers that don't handle currying and various other "readable" representations well.

Worse still, if your target output is readable, then someone might start touching the compiled runtime objects with Javascript and then... god help you as you watch the guarantees of your fancy type system unravel before your very eyes.

"readable output" isn't really about being human-readable, except in unrealistic example cases. The bigger benefit is shared data types; this helps immensely with JS interop.

https://rescript-lang.org/docs/manual/latest/shared-data-typ...

I feel like the dev team is using "readable output" to mean both "human-readable" and "shared data types" depending on the situation. And it creates a lot of confusion.

Spyder81 is partly right, 'readable' doesn't mean 'human-readable' per se, it means rather that the compiler tries very hard to produce output JS that looks like idiomatic, hand-written JS. This means things like:

- Uncurrying functions

- Compiling OCaml modules to idiomatic JavaScript objects

- Compiling OCaml record values to idiomatic JavaScript objects

- Compiling tail recursion to idiomatic while loops

- And so on.

> someone might start touching the compiled runtime objects with Javascript and then... god help you as you watch the guarantees of your fancy type system unravel before your very eyes.

That's exactly what genType is for--it produces JavaScript, TypeScript, and Flow interfaces for ReScript output code so that people in the JS world can consume it transparently.

not sure if it's FB's decision or the project maintainer's.

I am rather disappointed and think F# 's Fable is a better alternative.

Sorry to say, it's not. F# is nowhere near the wonderful type-sytem of Ocaml(although it's intentional). I would stick with js_of_ocaml for my js needs.

last time I check, did not find a way to integrate jsoo easily with existing js code. is it any tutorial on how to write a js lib using jsoo?

You have to write binding glue code. Last i saw reason also required binding code to work.

Here is a react binding for jsoo: https://github.com/jchavarri/jsoo-react .

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