servant VS coffeescript

> do you really have to understand language extensions?

You do when your code doesn't compile and you're trying to figure out what the error message means, or when the library you want to use makes heavy use of it for even basic functionality.

> These days one just enables GHC2021

My experience was pre-GHC2021. I basically had to enable at a minimum 5-6 language extensions in every single file.

> Mostly they're just about removing unnecessary restrictions from the older standard.

Yeah, those ones are usually fine. I have zero objection to things like FlexibleInstances or DeriveFoldable.

> Could you give an example?

I believe I was trying to implement Central Authentication Service using Servant. However, that required returning a custom HTTP status code. There has been an open Github issue for this since 2017, but it seems to require basically rewriting the entire framework: https://github.com/haskell-servant/servant/issues/732

Looking back at it now Servant does have "ServerError", but that basically requires giving up all the advantages Servant claims to have and I believe it was not a viable option at the time. Looking at the timeline I was probably also on Servant 0.15, and there seems to have been a rewrite since then.

I vaguely recall running into a similar issue trying to interact with a database, but I can't remember the details of that.

a HasSwagger instance for NamedRoutes was added in May 2022 (in this commit) but there hasn't been a package release since March

If you don't like this style, the usual alternative is to change mkDualAuthHandler to take two additional arguments, Proxy tag0 and Proxy tag1 (as e.g. lots of Servant functions do, for historical reasons).

Dunno if this is helpful, but I found this github issue about ResourceT and servant https://github.com/haskell-servant/servant/issues/1345

And what about the cabal repl --with-compiler=doctest, which was added recently, in doctest v0.20? I recently submitted a PR for Servant to use this in place of GHC environment files, because it seems less finicky to me. Was this a bad idea?

I asked a somewhat relevant question recently. Maybe you'll find this discussion somewhat helpful: https://github.com/haskell-servant/servant/issues/1547; two packages were talked about. One of the folks from Well Typed replied, and said they tried it recently (and worked fine).

You are highly encouraged to test this release out and let us know what you think ! For bug reports, features requests or any kind of feedback, just open a ticket on our issue tracker.

Even slower than :<|> quadratic compile time in number of routes?

Check this out https://github.com/haskell-servant/servant/issues/335#issuecomment-172300487

That said, there are ways to embrace the JS ecosystem without actually using JavaScript. Many popular languages have transpilers that will convert code written in that particular language into something that will run natively in a web browser (in other words, JavaScript). Even TypeScript is a language that gets transpiled into JavaScript, so it's not that outrageous of a concept, it just gets more difficult to do the further you get away from languages that don't already look like JavaScript.

As a front-end web developer, do you still use CoffeeScript or jQuery? Unlikely, as TypeScript, ES/TC39 and Babel (and the retirement of Internet Explorer thanks to @codepo8 and his EDGE team) have helped to transform JavaScript into some kind of a modern programming language.

CoffeeScript

On the other hand, companies choose React because that's where all the developers are. If you want to build something that can be maintained years from now, you better not choose the next hype train that goes straight to nowhere (remember CoffeeScript ?). You want something battle tested that has stood the test of time, where you won't have trouble finding developers to scale once you need to. And nobody ever got fired for choosing React.