wmakley

Lessons Learned From a Year of Elm

These are some of the lessons I wish I had learned when I first picked up Elm, before I wrote a bunch of apps that are now more difficult to maintain than they need to be.

1. Not Everything Needs to be a Package.

Breaking an Elm program up into multiple files just to reduce scrolling does not tend to work out optimally. Evan gave a really cool talk on this called "The life of a file". Files should split organically around data structures, not just to stay short. The reasons we want to keep JavaScript files as short as possible do not apply to Elm.

For example, I've created apps with a file structure like this:

JoelQ

-- 0.19

randomToTask : Generator a -> Task x a
randomToTask generator =
    Time.now
        |> Task.map (Tuple.first << Random.step generator << Random.initialSeed << Time.posixToMillis)


-- 0.18

eriklott

module YourAPIClient exposing (Config, otherFunctions)

import Http
import Json.Decode as Decode
import Json.Encode as Encode


-- Config

adamjstewart

#!/usr/bin/env bash

# There are many ways to get a path to a file or script.
# This script showcases several of them and their pitfalls.

# Credit for most of these techniques comes from:
# http://stackoverflow.com/questions/4774054/

abs_path='/usr/bin/bash'
rel_path='.'