rescript-js VS rescript

At Carla, we had a different situation. Having a huge codebase with Js, Belt, and WhateverExtra all over the place, it would be too much work to take some existing customized stdlibs like rescript-js or @dzakh/rescript-stdlib and update old code with them.

While the feedback was overwhelmingly positive, I noticed that despite having TypeScript support, many developers were hesitant simply because of "ReScript" in the name. So after months of dedicated development, I'm excited to present you Sury - a TypeScript-first schema validation library that brings all those amazing features while staying true to its ReScript roots 🔥

When I see this it makes me want to run for ReasonML/ReScript/Elm/PureScript.

Sum types (without payloads on the instances they are effectively enums) should not require a evening filling ceremonial dance event to define.

https://reasonml.github.io/

https://rescript-lang.org/

https://elm-lang.org/

https://www.purescript.org/

(any I forgot?)

It's nice that TS is a strict super set of JS... But that's about the only reason TS is nice. Apart from that the "being a strict super set" hampers TS is a million and one ways.

To my JS is too broken to fix with a strict super set.

Interestingly, you probably think that calling eval itself is slow, and I thought this myself. However, it was actually not as slow as I expected. For example, creating a simple nested object schema and calling the parser once happened to be 1.8 times faster with ReScript Schema using eval than Zod. I really put a lot of effort into making it as fast as possible, and I have to thank the ReScript language and the people behind it for allowing me to write very performant and safe code.

Fortunately, the OCaml compiler is very modular, and there have been efforts to make things more... reasonable.

- Reason, a different syntactic frontend for regular OCaml: https://reasonml.github.io/

- ReScript, a language with OCaml semantics that compiles into: JS https://rescript-lang.org/ (I suppose it's a reincarnation of js-of-ocaml).

Elm, ReScript, F#, Ocaml, Scala… it’s just normal to name your types, then use them places. In fact, you’ll often create the types _before_ the code, even if you’re not really practicing DDD (Domain Driven Design). Yes, you’ll do many after the fact when doing functions, or you start testing things and decide to change your design, and make new types. Either way, it’s just “the norm”. You then do the other norms like “name your function” and “name your variables”. I’m a bit confused why it’s only 2 out of 3 (variables and functions, not types) in this TypeScript Angular project. I’ll have to look at other internal Angular projects and see if it’s common there as well.

A web application makes use of these same ingredients, i.e. HTML, CSS, and JavaScript, but it uses significantly more JavaScript. As the JavaScript powering your web application grows in size it can bring with it a variety of problems that a few languages, like TypeScript, ReScript, PureScript, and Elm, have attempted to solve. Each of the aforementioned compile to JavaScript languages have their pros and cons but it is beyond the scope of this article to get into those details. Suffice it to say, my preference is Elm. It is also not the goal of this article to convince you to use Elm but only to show you how Elm fits into the flow of creating a web application and hosting it on GitHub Pages. So let's continue by adding Elm to our project.

Since JavaScript doesn't have a pattern-matching like Rust, it could be hard to replicate the same logic. I used the ReScript compiler to maintain the original logic as much as possible. It made me able to port it confidently. Specifically check_pair function can be converted into this.