Discussion on: rubico simplifies asynchronous code

View post

I really liked that style of writing, although the first few sentences at first glance had nothing to do with javascript like the title promised the storytelling kept me reading.

But how is this different from rxjs, I feel like I could acomplish the same task with the same level of readability with rxjs, which I and probably others know well from working with angular? Is it that it's truely functional and can be used with other functional libraries like lodash/fp or ramda which rxjs cannot?

Indeed it looks promising because Promises are great and way better than callback hell but still somewhat cumbersome to work which. Recently I needed to compose sync and async functions together and ended up wrapping the sync function in Promise.resolve() and then compose them with Promise.all() which worked but looked a bit silly. How would this look like with rubico?

Richard Tong • Jul 15 '20

Here's a table from one of my archived posts that highlight some differences of rubico and rxjs

Features of RxJS	Features of rubico
special asynchronous stream datatype, the Observable - wraps built-in types for reactive operations down the line	no special data types: rubico works out of the box for built-in types; this includes async iterables
familiar design pattern: the Observer pattern - plugs into Observables	no design pattern lock-in: rubico composes your functions together. You choose the design pattern
interop with Promises	fully managed Promises: rubico stops you from having to manually resolve Promises, for example having to call `Promise.all` on an array of Promises
functional programming style via Operators + `Observable.prototype.pipe`	functional programming style by design

Roadblocks for RxJS	More Features of rubico
async iterables undermine the need for rxjs's core datatype: the Observable.	async iterables make rubico great; the async iterable is a core rubico (and JavaScript) datatype
multitude of concepts	simple foundational concept: just pipe functions together
large API surface	small, cohesive API surface
RxJS is hard to learn	rubico is easy to learn

If you had sync and async functions that you wanted to compose together in a pipe, with rubico it would like something like

pipe([
  syncFnA,
  asyncFnA,
  syncFnB,
  asyncFnB,
])(someValue) // Promise { someOutput }

rubico pipe and other functions that accept functions all handle promise resolution for you. Conversely,

pipe([
  syncFnA,
  syncFnB,
])(someValue) // someOutput

If no functions are asynchronous, you'll get a synchronous value not wrapped in a Promise