purescript-halogen VS reagent

There's a framework in purescript from which u can grab some ideas I think: https://github.com/purescript-halogen/purescript-halogen.

If you wanna do web frontends right now, I'd recommend Halogen for Purescript since it is maintained and has documentation.

Before 2012, all of my websites were made using HTML, CSS and a sprinkling of JS. Then, I went all-in on AngularJS, followed by React. I started using Typescript and then PureScript and learned more frameworks like Halogen and Concur. I even wrote my own UI framework called purescript-deku.

First of all I had to choose what to use to manage the User Interface. I narrowed down to two modules: Halogen and react-basic-hooks (which is a “wrapper” of the unmaintained react-basic). I decided to go with react-basic-hooks just because I work with React on a daily basis and I wanted to understand its interoperability with PureScript. I will 10/10 try Halogen too in the next future since as far as I can see is the most famous and maintained in the PureScript community.

There's also Purescript, which is sort of a Haskell for frontend. It has type classes, HKTs and so on and also has a very nice FFI. When it comes to UI libraries there is Halogen which I think is very well though out and allows for using tagless final approach. There's also react-basic but I haven't used that one myself.

My favorite webapp stack at the moment is Halogen (PureScript UI library); I have always gravitated toward functional programming and strong static typing. For commercial work, however, I use React. While it isn’t perfect it strikes, for me, the right balance of purity, composability, and simplicity.

Yeah? I wrote something to deal with it too (https://github.com/toastal/return-optics) 5.5 years ago. You arguably chose the wrong data as `(model, Cmd msg, Maybe extMsg)` instead of `(model, Cmd msg, List extMsg)` which would give you more flexibility and still functions as a monoid on [] instead of Nothing, but allows multiple messages shrug. I tried this approach more recently and it involved me having to encode all of actions in a massive tree and then I still had issues with certain messages including now having to UUID all elements that that previously I didn't need to think about. It was a mess, but the best I could do with the tools at hand.

If you compare this to Halogen (https://github.com/purescript-halogen/purescript-halogen/blo...) where you still have purity but can set up subscribers and listeners from any component. It's much easier to use and for some components like dialogs, it's much simpler. And this actually isn't the best example because with the latest Halogen, Portals (https://github.com/purescript-halogen/purescript-halogen/pul...) was introduced so you can launch a dialog on the spot instead of even needing to communicate between them at all.

Below you can find the example of a simple button component written in Halogen:

Generating `HTML` from lisps has poisoned any other approach for me, see for example https://www.neilvandyke.org/racket/html-writing/, https://reagent-project.github.io/, and https://edicl.github.io/cl-who/

Hiccup syntax for Clojure uses hash maps (curly braces) for attrs, e.g. `{:style {:background "red" :margin "1em"}`

See Reagent which uses Hiccup synta: https://reagent-project.github.io/

    (defn simple-component []

* Single-Page App: shadow-cljs for the build concerns (https://github.com/thheller/shadow-cljs), Reagent with Re-frame for complex/large app (https://reagent-project.github.io and https://github.com/day8/re-frame). Even if we now prefer using HTMX (https://htmx.org) and server-side rendering (Hiccup way of manipulating HTML is just amazing, https://github.com/weavejester/hiccup).

The API documentation lists the most commonly and rarely used parts before going into detail and there are many usage examples.

Reagent has a nice intro tutorial (classic todo-app): http://reagent-project.github.io and many other helpful tutorials and resources for beginners: https://cljdoc.org/d/reagent/reagent/1.2.0/doc/documentation...

However, since Reagent is still stuck with class-components for more complex behavior and relies on Hiccup, which is nice but has a performance cost compared to pure React, I am unsure about its future. Like some others in the Clojure community, I have moved to thin React wrappers like Helix and use Refx to integrate those with re-frame. It may be a bit confusing right now for beginners since there is no “golden path”.

Also, unfortunately, many smaller libraries are poorly documented and it seems like it is expected from the developer to dig into the source code to find out what’s going on.

What I found the most difficult as a beginner was how to setup a project in ClojureScript in the first place, like all the configuration in shadow-cljs, how it interacts with deps.edn, how it integrates with npm, the REPL, etc. But dev/build config has always been a weak spot for me, so it might be just that.

Overall, I still very much enjoy working with Clojure(Script), more than in any other language. Anyone who likes Lisps and functional programming should give it a try (and be sure to watch Rich Hickeys amazing talks!).

have you tried cljs and reagent? it’s a different vibe.

my bootstrap: https://github.com/nathants/aws-gocljs

the project: https://reagent-project.github.io/

Clojure people have been doing this for a decade or so. It’s really so much better to work with. All started with Hiccup and when React came along you got Reagent and many more developments building on the idea.

> But Reagent supports functional components as well, with hooks and all.

I addressed this already: while reagent is able to emit function components, there is a performance penalty to this.[1]

> I also very much like Hiccup, and so do many of us, because code is data and data is code, and Helix has decided not to support that.

Hiccup is convenient to write, but it is a constant run-time cost and a significant storage cost given that you have to store long series of constructors to cljs.core.PersistentVector in your bundle, have the JS runtime actually construct the vector, then pass it through a Hiccup interpreter to finally produce DOM nodes and throw away the persistent vector, only to repeat this entire process again on re-render.[2]

> Helix has decided not to support that.

That is simply not true. From the Helix documentation[2],

> If you want to use libraries like sablono, hicada or even hx hiccup parser, you can easily add that by creating a custom macro.

These are all Hiccup interpreters you can readily use.

IME there is very little difference between using the $ macro in Helix and writing Hiccup. I do not really miss Hiccup when I use Helix, and you still have data as code ;)

While this is from an unrelated project, there are benchmarks[3] done against Reagent that demonstrate the sheer overhead it has. In practice it is not a big problem if you rarely trigger a re-render, but otherwise it is a non-trivial cost, and if you want to use modern React features (like Suspense), there is a lot of r/as-element mingling going on, converting cases, etc. that simply make Reagent feel more tedious to use than Helix.

Also, the newer UIx2, which largely borrows from Helix, is "3.2x faster than Reagent" according to one of the contributors.[4]

I think it'd be worthwhile to benchmark all of these libraries against each other and record the data in one place. Maybe I'll get around to doing it this weekend :)

---

[1] https://github.com/reagent-project/reagent/blob/master/doc/R...

[2] https://github.com/lilactown/helix/blob/master/docs/faq.md#w...

[3] https://github.com/roman01la/uix#benchmarks

[4] https://github.com/pitch-io/uix/pull/12

Reagent is peak React. All the good stuff without any of the hook and readability problems the article describes.

No affiliation, happy user for years.

https://github.com/reagent-project/reagent