virt-v2v VS Elm

In virt-v2v we eventually enforced that every module file also has a corresponding interface file: https://github.com/libguestfs/virt-v2v/blob/master/check-mli...

You can look at the project yourself: https://github.com/libguestfs/virt-v2v I've been writing OCaml for 20+ years and C for 40 years.

I develop in OCaml from time to time, and it's pretty practical. Separate compilation, makes small-ish binaries that most people wouldn't know weren't written in C/C++, easily call out to C if you need to. We steer clear of the more complex language features like functors because they confuse most programmers.

Here's an example of one very widely used production application: https://github.com/libguestfs/virt-v2v/tree/master/v2v

XPath is the real killer feature for XML. I don't think it's possible to use it in this particular example, but in the more generally useful cases where you want to pull (eg) all subnodes with key matching a particular string, XPath is great.

Here's it being used in real code (search for "xpath_"):

https://github.com/libguestfs/virt-v2v/blob/master/v2v/parse...

https://github.com/libguestfs/virt-v2v/blob/master/v2v/parse...

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.

I think the most fun and approachable way for beginners to build games with functional programming is with Elm [1].

See a few (small, demo) games built by the community in [2] .

Notice Elm has abandoned the FRP approach in favor of Model-View-Update [3].

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