refute VS fantasy-land

I find straight forward, dedicated combinators much more readable and practical to use ie. for iterables (context where it makes a lot of sense) [0] example [1], runtime assertions (through refutations, which are much faster than combinators over assertions) [2], parser combinators for smallish grammars [3] etc.

In many cases vanilla/imperative js is more readable and terse, no need to bring functional fanaticism everywhere, just in places where it gives true benefits and in form that can be understood by peers.

Functional code can be beautiful and can also be unreadable/undebugable. Same with imperative code. It's great in js/ts you can pick approach where the problem is expressed more naturally and mix it at will.

[0] https://github.com/preludejs/generator

[1] https://observablehq.com/@mirek/project-euler

[2] https://github.com/preludejs/refute

[3] https://github.com/preludejs/parser

We use jsonrpc over websockets in production for many years in trading services. It works very well. We use lightweight libraries that look like this [0] and this [1]. It's lightweight, fast, type safe, easy to maintain and debug etc.

[0] https://github.com/preludejs/jsonrpc

[1] https://github.com/preludejs/refute

Types can be asserted at runtime (parsed) at IO boundaries (reading http request or response, websocket message, parsing json file etc). Once they enter statically type system they don't need to be asserted again.

The difference it makes is illusion of type-safety vs type-safety this article touches on.

You can try to bind service with client somehow but in many cases this will fail in production as you can't guarantee paired versioning, due to normal situations by design of your architecture or temporary mid-deployment state or other team doing something they were not suppose to do etc. It's hard to avoid runtime parsing in general.

Functional combinators [0] or faster [1] with predicate/assert semantics work very well with typescript, which is very pleasant language to work with.

[0] https://github.com/appliedblockchain/assert-combinators

[1] https://github.com/preludejs/refute

2. https://github.com/fantasyland/fantasy-land (A bit heavy on jargon)

Note there is a python version of Ramda available on pypi and there’s a lot of FP tidbits inside JAX:

3. https://pypi.org/project/ramda/ (Worth making your own version if you want to learn, though)

4. For nested data, JAX tree_util is epic: https://jax.readthedocs.io/en/latest/jax.tree_util.html and also their curry implementation is funny: https://github.com/google/jax/blob/4ac2bdc2b1d71ec0010412a32...

Anyway don’t put FP on a pedestal, main thing is to focus on the core principles of avoiding external mutation and making helper functions. Doesn’t always work because some languages like Rust don’t have legit support for currying (afaik in 2023 August), but in those cases you can hack it with builder methods to an extent.

Finally, if you want to understand the middle of the midwit meme, check out this wiki article and connect the free monoid to the Kleene star (0 or more copies of your pattern) and Kleene plus (1 or more copies of your pattern). Those are also in regex so it can help you remember the regex symbols. https://en.wikipedia.org/wiki/Free_monoid?wprov=sfti1

The simplest example might be {0}^* in which case

0: “” // because we use *

It was never really my jam, but I used to follow the up-and-coming fantasy-land specs with great interest. It just seemed like a sharp dedicated community of folks trying to figure out better fp & algebraic stuff. I'm not sure who trailed off - in general I feel like there's much less connection in tech world, that the tech twitter and every other ultra-active tech channel has somewhat decayed. https://github.com/fantasyland/fantasy-land

Thanks for the links. I know I've seen @gcanti's name a thousand times already, but it's already quite murky to me what it was attached to. Something in this sphere.

Look at the implementations of Fantasy Land. List-in-JS might do the trick.

There are respective fantasy land and static land specs, with the law conformance checks.

While building a purely functional data structure library for personal fun and professional use, and while using other libraries, I found that the "Fantasy Land Specification" was mentioned from time to time. They use this hierarchy. Although I did read some about category theory (tried and failed to fully understand all the concepts), some of the terms used in the specification are unknown to me (like Chain, Apply). My question:

No: neither of those examples are "properties of futures and of lists as such." "Async/Await" in particular is a special case of monadic behavior of a concurrency monad. This specifically (infamously) came up in the evolution of the Prommise spec in ECMAScript, which in turn led to the development of the Fantasy Land Spec and various implementations of it.

If you're programming in TypeScript you can checkout the fantasy land spec. It provides a spec for all the algebraic structures used in the JS world. You can learn what they are. You'll want to find alternative resources to learn what they are how they work. Fantasy land is just a spec not a guide.

Javascript comes with this lovely little spec called Fantasy Land that defines certain type classes in Category Theory and how they interact.