Elm VS idris

I have first heard about it when I was working with Elm [1] through a popular blog post (at the time) How elm slays a UI antipattern.

Elm [1] is based on a similar idea. Build your app from pure functions that return HTML tags.

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

You also wouldn't really be creating your own new programing language. You would be creating something that can run JavaScript by following JavaScript standards and syntax. You might be able to add some non-standard features of your own on top of those standards, or include your own standard library of helpers or utilities, but you can't completely make a new or alternative language and then load it in the browser (or at least not by reimplementing ECMAScript standards... you actually can make your own language that runs within any Javascript enviroment, if you provide an interpreter or compiler that transforms it into valid JS. Some people have done something like this, eg Elm: https://elm-lang.org/).

You should at least have a look at https://elm-lang.org/ it is a pure functional language like Haskell (although with fewer fancy syntax/type classes) but it has some lovely libraries for visualisation and even with plain elm (+ elm-ui) doing string transformations can be easily done.

I get it. However, the whole point of using Unions to narrow your types, ensure only a set of possible scenarios can occur, and only access data of a particular union when it’s safe to do so. That’s some of what pattern matching can provide, and 100% of what using switch statements in TypeScript with their Discriminated Unions can provide. Yes, it’s not 100% exhaustive, but TypeScript is not soundly typed, and even Elm which is still has the same issue TypeScript does: You’re running in JavaScript where anything is possible. So it’s good enough to build with and much better than what you had.

The beauty of a language like Elm (and other lambda-calculus / functional programming inspired languages) is that there's very little transformation involved in going from an idea to code. And that seems to have a big impact on getting things done.

there're a lot of languages that can target js/wasm these days, some of which are even self-hosting (ghc) and can target browser (ghcjs), a lot are written in haskell which again can target browser but the closest to my request i've found is an old thread of idris supposedely compilable by ghcjs and while there are plenty "run your code in browser (via server compilation)" services i've yet to see a working "running compiler in browser in browser example"

So apparently there's a package manager called Inigo, but there are only a few packages in it. There's an idris-hackers group on github, that's linked from the idris-lang.org page. None of those libraries appear in Inigo though. So seems that Inigo isn't really a thing people are using.

Here's Idris' Nat optimisations

As of 2013, Idris does not want to even support user defined Unicode operators, for the usual reasons.