dream-html VS hobbes

FOR some time now, I have been maintaining an OCaml library called dream-html. This library is primarily intended to render correctly-constructed HTML, SVG, and MathML. Recently, I added the ability to render well-formed XML markup, which has slightly different rules than HTML. For example, in HTML if you want to write an empty div tag, you do:

htmx is a JavaScript library which interprets a set of HTML attributes and JavaScript events. It doesn't have anything to do with static typing. However, it's fairly easy to add a statically-typed layer on top of it eg https://github.com/yawaramin/dream-html

There is some truth to this. Imho the next level of htmx is unlocked when you componentize everything like a React app...but with nested routes corresponding to nested components like a Remix app...and using an HTML generation DSL embedded directly in your language, so HTML becomes a first-class citizen of your language's constructs, rather than a templated afterthought. I have a demo of this: https://github.com/yawaramin/dream-html/tree/todoapp/app

Nowadays I highly recommend HTML embedding libraries directly in the programming language. E.g. ScalaTags https://com-lihaoyi.github.io/scalatags/ or (my own) https://github.com/yawaramin/dream-html

Yes, you give up the ability of designers and frontend-only people to easily work with the HTML templates. But in exchange you get quite a lot.

I found your article very informative and it matches up quite a bit with my own thinking about HTML generation. In fact it looks like we independently arrived at pretty much the same conclusions. A lot of the issues you raise are the impetus behind the way I designed my HTML-generation DSL: https://github.com/yawaramin/dream-html

I am developing an HTML generation library on top of Dream, to have great support in the language including htmx support: https://yawaramin.github.io/dream-html/dream-html/Dream_html/index.html

Look at this code which prints out an HTML tag: https://github.com/yawaramin/dream-html/blob/main/lib/dream_...

Initially you might think generating HTML tags from data structures in code should be a simple matter. But there are complexities--some tags are defined as having no child tags, others do. Some tags are purely character data (unstructured text), not structured data. Some are just comments. We need a way to compose multiple tags together into a single 'virtual' tag for flexible HTML generation. All these conditions can be pretty hard to keep track of--unless your compiler does exhaustiveness checking. Then the compiler will tell you if you missed any cases.

In the example above I didn't make any manual effort to cover all the cases, I simple listed out the cases I wanted to handle in order. The compiler made sure that I didn't miss any.

https://github.com/morganstanley/hobbes

Things like structural equality and ordering are user functions here rather than magic internal definitions (e.g. equality is defined as a type class, and type class instances can deconstruct algebraic types at compile time to decide how to implement instances). But evaluation is eager by default, so it's pretty easy to reason about performance. And data structures can be persisted to files and/or shared transparently in memory with C/C++ programs without translation, also very convenient for the places where this was used. Actually we built some very big and complicated time series databases with it, used in both pre and post trade settings where ~15% of daily US equity trades happen. So I think these observations are useful and have passed through some pretty significant real tests.

Have a look at Hobbes from Morgan Stanley

https://github.com/morganstanley/hobbes

This approach has several benefits, but there's a lot of appeal also to the way they're doing it, to have the same PL across stages (and then maybe have more than just two stages).