This code was quickly ripped out of an active project to serve as an example. It will not compile in any way!
Any questions? Add them to the comments!
| object ScalaJSExample extends js.JSApp{ | |
| def main() = { | |
| val xs = Seq(1, 2, 3) | |
| println(xs.toString) | |
| val ys = Seq(4, 5, 6) | |
| println(ys.toString) | |
| val zs = for{ | |
| x <- xs | |
| y <- ys | |
| } yield x * y |
(by @andrestaltz)
If you prefer to watch video tutorials with live-coding, then check out this series I recorded with the same contents as in this article: Egghead.io - Introduction to Reactive Programming.
(by @andrestaltz)
So you're curious in learning this new thing called (Functional) Reactive Programming (FRP).
Learning it is hard, even harder by the lack of good material. When I started, I tried looking for tutorials. I found only a handful of practical guides, but they just scratched the surface and never tackled the challenge of building the whole architecture around it. Library documentations often don't help when you're trying to understand some function. I mean, honestly, look at this:
Rx.Observable.prototype.flatMapLatest(selector, [thisArg])
Projects each element of an observable sequence into a new sequence of observable sequences by incorporating the element's index and then transforms an observable sequence of observable sequences into an observable sequence producing values only from the most recent observable sequence.
| - What do Etcd, Consul, and Zookeeper do? | |
| - Service Registration: | |
| - Host, port number, and sometimes authentication credentials, protocols, versions | |
| numbers, and/or environment details. | |
| - Service Discovery: | |
| - Ability for client application to query the central registry to learn of service location. | |
| - Consistent and durable general-purpose K/V store across distributed system. | |
| - Some solutions support this better than others. | |
| - Based on Paxos or some derivative (i.e. Raft) algorithm to quickly converge to a consistent state. | |
| - Centralized locking can be based on this K/V store. |
Every application ever written can be viewed as some sort of transformation on data. Data can come from different sources, such as a network or a file or user input or the Large Hadron Collider. It can come from many sources all at once to be merged and aggregated in interesting ways, and it can be produced into many different output sinks, such as a network or files or graphical user interfaces. You might produce your output all at once, as a big data dump at the end of the world (right before your program shuts down), or you might produce it more incrementally. Every application fits into this model.
The scalaz-stream project is an attempt to make it easy to construct, test and scale programs that fit within this model (which is to say, everything). It does this by providing an abstraction around a "stream" of data, which is really just this notion of some number of data being sequentially pulled out of some unspecified data source. On top of this abstraction, sca
A primer/refresher on the category theory concepts that most commonly crop up in conversations about Scala or FP. (Because it's embarassing when I forget this stuff!)
I'll be assuming Scalaz imports in code samples, and some of the code may be pseudo-Scala.
A functor is something that supports map.
In this gist I would like to describe an idea for GraphQL subscriptions. It was inspired by conversations about subscriptions in the GraphQL slack channel and different GH issues, like #89 and #411.
At the moment GraphQL allows 2 types of queries:
querymutationReference implementation also adds the third type: subscription. It does not have any semantics yet, so here I would like to propose one possible semantics interpretation and the reasoning behind it.
These use separate document structures instead of HTML, some are more modular libraries than full editors
This document is about Task, an alternative for Scalaz's Task or Scala's Future.
Note this is work in progress and this document suffered multiple modifications already: