fp-ts VS ts-toolbelt

I think it’s great that functional programming is making its way into traditional imperative languages - even JavaScript (I recently came across https://gcanti.github.io/fp-ts/ as a pretty extreme example)

Elixir/Erlang has function-level pattern matching, which I really like. I’ve yet to see it anywhere else, though my understanding is it came from Prolog.

While I certainly agree, I've found that this is often an indication of too-complex an architecture, and a fundamental re-think being necessary. I've had projects that depend on [fp-ts], which end up incredibly generic-heavy, but still make it entirely through a typecheck(not build- typescript's just worse at that than other tools like esbuild) in seconds-at-worse.

Obviously depends on your organization/project/application, but I do like these things as complexity-smells.

[fp-ts]: https://gcanti.github.io/fp-ts/

Unlike more comprehensive functional libraries like fp-ts, each module can be imported and resolved separately. If you just need options, simply add the option module and you're good to go.

While it's quite abstract, I believe it may be useful to those of you who is interested to learn more about functional programming [in Typescript] and also get more intuition on diverse programming ideas. I use fp-ts as a functional programming library there.

The library for TypeScript that this is influenced by is here:

https://github.com/gcanti/fp-ts

Interesting how both languages with this library converge to a similar syntax, due to heavy use of functions.

Learn something that pays the bill first - nowadays it's Golang/Rust react/typescript. Then you can try some pure fp libs like fp-ts and fp-core.rs, and look through existing scala cats docs. If you'll feel bad about it - that's totally fine and expectable, fp takes a paradigm shift and not that many dev able to shift their brains way of thought due to basic psychological rigidity) (inability to change habits and to modify concepts/attitudes once developed). And that's purely a staffing and management issue - folks hired randoms out of the blue, and called 'em a team.

fp-ts, a library that caters to functional programming in TypeScript, comes with some micro-abstractions that already solve a few of our needs.

Also, don't underestimate how powerful TypeScript can be in capable hands (namely Giulio Canti's). Check out fp-ts, for instance.

You are able to type it using function overloads, an example can be found here - link, line 236.

looks like more ergonomic/focused version of fp-ts[1]

[1] https://gcanti.github.io/fp-ts/

There are a bunch of awesome type utility libraries that may boost your works on types, like ts-toolbelt, utility-types, SimplyTyped, etc., which you can already use.

We have only scratched the surface of type manipulation in Typescript, if you want to get your mind blown, checkout community projects like ts-toolbelt and type-challenges.

Do you mean https://github.com/millsp/ts-toolbelt? You didn’t provide a link so I’m not sure which repo you’re referring to.

I am guessing that since it does not exists as an built in type, in utility-types, or in ts-toolbelt that it currently isn't possible.

Since posting this, some comments have made me aware that ts-toolbelt has this feature and a couple other really useful ones built in. So their source code could be worth skimming through to see how they did things.

I was curios enough to dug the definition along with a related types Narrowable and Cast

ts-toolbelt has a "Path" Type https://github.com/millsp/ts-toolbelt