staltz

The introduction to Reactive Programming you've been missing

(by @andrestaltz)

---

This tutorial as a series of videos

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.

---

evancz

Union Types

If Elm community is going to begin referring to "union types" instead of "algebraic data types" we should think about how that will work in practice. What discussions will we have? Will we find ourselves in awkward spots trying to explain things?

The following question/answer pairs simulate things I'd expect to see in a world of "union types". The pairs are grouped by what background I expect the questions to come from so we know the subtext. I have also added some meta comments in italic to explain my phrasing.

One thing to consider is that a lot of learners will not have a person to ask, so the path to arriving at these answers needs to be easy if you are just searching online.

General Questions

cscalfani

Default Values in Elm

Using Maybe

In Elm, optional values are handled with Maybe. The following functions show a simple implementation of optional parameters:

combineOpts : Maybe String -> Maybe String -> String -> String -> String
combineOpts = prefix suffix s1 s2 =

kennetpostigo

First couple things I thought about when migrating after reading the docs

So migrating my existing app wasn't as troublesome as I originally thought. First thing I did was take a look at my router and routes and figure try to make a mental model of all the files where I had nested routes in the existing app because those components/containers will contain {this.props.children}. So I need to replace those with the nested <Match /> components.

So just to give an example:

In v2:

<Router history={history}>
  <Route path="/" component={App}>