rescript-compiler VS melange

If you’re a front-end developer, you should checkout ReScript[1], supposedly a JS-oriented successor of ReasonML and developed by the ReasonML team.

[1] https://rescript-lang.org/

ReScript is "Fast, Simple, Fully Typed JavaScript from the Future". What that means is that ReScript has a lightning fast compiler, an easy to learn JS like syntax, strong static types, with amazing features like pattern matching and variant types. Until 2020 it was called "BuckleScript" and is closely related to ReasonML.

As another commenter has already suggested, ReasonML has a lot of what you described here.

However, modern JS-oriented toolchain for ReasonML is called ReScript and you can learn more here: https://rescript-lang.org/

ReScript (before BuckleScript) https://rescript-lang.org/ is a functional language that can also use OOP. Ideal for Javascript and Typescript projects, React and servers. It integrates perfectly with Javascript and Typescript code https://rescript-lang.org/docs/react/latest/introduction

Thank you!

We invited Gabriel because we think what he's building is pretty cool. It showcases so much about EdgeDB: its type system, data model, query language, composability, introspection, etc.

I'm not a ReScript user myself. What I know is that it's a functional programming language somewhat heavily inspired by OCaml. Their website goes into details [1]

[1] https://rescript-lang.org/

You might want to look into ReScript (https://rescript-lang.org/). It has strong static typing with type inference, and it is very fast.

This is because a “Tagged Union”, another word for TypeScript’s Discriminated Union, is a way to “tag which one is in use right now… we check the tag to see”. Just like when you’re shopping and check the tag of a piece of clothing to see what the price is, what size it is, or what material it’s made out of. Languages like ReScript compile many of their Unions (called Variants) to JavaScript Objects that have a tag property.

ReScript is "Fast, Simple, Fully Typed JavaScript from the Future". Let's take a look at how we can add it to an existing React project.

REscript

Ultimately, Dhall wasn’t verbose enough nor was I Dhall ninja, but something like TypeScript or ReScript probably would have been better.

Hey HN, at Ahrefs we have been working on an online book that hopefully helps React developers get up and running with Melange, an OCaml to JavaScript compiler. You can read more about Melange here: https://melange.re/.

There are still a few chapters that we'd like to add before considering it "complete", but it might be already helpful for some folks out there, that's why we decided to publish it early.

The book uses Reason syntax to implement React components using ReasonReact components. You can read more about both in:

https://reasonml.github.io/

In my previous post on trying to use the NextJS App Router and Reason I described some of the problems and limitations of their compatibility with one another. With the release of Melange 2 I decided to see if the new features of Melange 2 could help to increase the compatibility of Reason and the NextJS App Router. I have also documented some of the things learnt after trying Melange (v1) with Astro and Remix.

So it's Reason, not ReasonML which the umbrella project's name, and Rescript is a imcompatible syntax split from the Bucklescript team (that previously transpiled Reason to JS). Bucklescript's new name is... Rescript.

But not everyone agrees with the split and work is being done on Melange to replace Bucklescript : https://github.com/melange-re/melange

Ultimately JsOfOcaml can directly transpile Ocaml to JS.

In reality, most folks that developed BuckleScript frontends with ReasonML switched to ReScript syntax and are happy with it. Some felt more friction because of their reliance on PPXes or FP-heavy libraries (like Relude) and those people tend to use the Melange fork of BuckleScript or they switched to js_of_ocaml.

There is a fork of ReScript that supports ReasonML syntax and with the goal of maintaining Ocaml compatibility: https://github.com/melange-re/melange.

There's also a fork of BuckleScript/ReScript called Melange that guts its build system so that instead of using ninja, it works with more standard tools for the ecosystem, specifically dune and esy. In doing so they managed to also finally get the compiler off of OCaml 4.06: now it can use a newer OCaml compiler and take advantage of four years worth of language and compiler improvements.

For OCaml and ReasonML your options are js_of_ocaml (mentioned here in ReasonML docs) or a fairly new fork of BuckleScript called melange. They differ in implementation and output, with JSOO taking intermediate bytecode generated by ocamlc and turning it into unreadable JS, vs Melange being a patched compiler that builds more human-readable JS.