fantasy-land VS newtype-ts

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.

Curious what your issue was with duck-typing. Were you effectively looking to create ADTs that are required to go through a specific step-by-step process, not simply 'look like' the thing that was expected?

If so, you might be interested in [newtype-ts].

[newtype-ts]: https://github.com/gcanti/newtype-ts

this one https://github.com/gcanti/newtype-ts ?

You don't need classes for nominal types: https://github.com/gcanti/newtype-ts

Creating newtypes (via newtype-ts) for fractions and percentages is worthwhile if you're very concerned about correctness, though it's unfortunate that absent typeclasses they're not terribly ergonomic.

I haven't used this library in particular or this one, but bless the authors and all the others for trying to make it happen… the project I'm now leading uses strongly typed strings for different component addresses, and it saves me to constantly look up the documentation what the functions need – it's beautiful.

A "nominal" solution with no runtime overhead can be provided by branded types, other words for this are "opaque types" or "newtypes". Some libraries like newtype-ts exist to help with the construction of these. That library README describes it as:

You can also look at the fp-ts ecosystem for inspiration. newtype-ts and io-ts's Branded type with io-ts-type's UUID as a good example

Alternatively we can use other more sophisticated techniques to achieve nominal typing or libraries such as: newtype-ts or io-ts.

One using fp-ts and newtype-ts

We are going to use newtype-ts to build a branded type: