melange VS Nim

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.

With function overloading and templates

You just use a `hash` function in your library code and user has to implement a version of it that accepts the Foo type.

To resolve the scope problem, Nim uses templates[1] with `dirty` pragma (makes template unhygienic), but there is also a `mixin`[2] statement for later static binding.

0 - https://github.com/nim-lang/Nim/lib/pure/collections/tables....

1 - https://github.com/nim-lang/Nim/blob/78983f1876726a49c69d656...

2 - https://nim-lang.org/docs/manual.html#generics-mixin-stateme...

Check out Nim[0] - it's strongly typed, with good type inference, clean elegant syntax, memory management is automatic (optional gc, default is ARC + small footprint cycle collector), compiles to small single binaries (Hello World is less than 100 kb), has powerful metaprogramming and lsp support.

Nim compiles to C/C++ and then to native code, so performance is on the same level as Rust/C/C++. You can also compile Nim to js/wasm and run the same code in the web.

[0] - https://nim-lang.org

Programming Language: Nim

Take a look at Nim.

You get C performance, with the readability of Python.

https://nim-lang.org/

It’s not exhaustive/definitive yet (should be for the actual release), but this might be helpful:

https://github.com/nim-lang/Nim/blob/devel/changelog.md

22. Nim - $80,000

I think the right answer to your question would be NimLang[0]. In reality, if you're seeking to use this in any enterprise context, you'd most likely want to select the subset of C++ that makes sense for you or just use C#.

[0]https://nim-lang.org/