Andrey Kuzmin w0rm

Learning FP the hard way: Experiences on the Elm language

by Ossi Hanhinen, @ohanhi

with the support of Futurice 💚.

Licensed under CC BY 4.0.

Editorial note

Should be work with 0.18

Destructuring(or pattern matching) is a way used to extract data from a data structure(tuple, list, record) that mirros the construction. Compare to other languages, Elm support much less destructuring but let's see what it got !

Tuple

myTuple = ("A", "B", "C")
myNestedTuple = ("A", "B", "C", ("X", "Y", "Z"))

	#Deploy and rollback on Heroku in staging and production
	task :deploy_staging => ['deploy:set_staging_app', 'deploy:push', 'deploy:restart', 'deploy:tag']
	task :deploy_production => ['deploy:set_production_app', 'deploy:push', 'deploy:restart', 'deploy:tag']

	namespace :deploy do
	PRODUCTION_APP = 'YOUR_PRODUCTION_APP_NAME_ON_HEROKU'
	STAGING_APP = 'YOUR_STAGING_APP_NAME_ON_HEROKU'

	task :staging_migrations => [:set_staging_app, :push, :off, :migrate, :restart, :on, :tag]
	task :staging_rollback => [:set_staging_app, :off, :push_previous, :restart, :on]

	// jQuery.support.transition
	// to verify that CSS3 transition is supported (or any of its browser-specific implementations)
	$.support.transition = (function(){
	var thisBody = document.body \|\| document.documentElement,
	thisStyle = thisBody.style,
	support = thisStyle.transition !== undefined \|\| thisStyle.WebkitTransition !== undefined \|\| thisStyle.MozTransition !== undefined \|\| thisStyle.MsTransition !== undefined \|\| thisStyle.OTransition !== undefined;

	return support;
	})();

	<!doctype html>
	<html>
	<head>
	<title>Resolution independent rendering of Bezier curves in WebGL</title>
	<meta http-equiv="content-type" content="text/html; charset=UTF-8">
	<script src="glMatrix-0.9.6.min.js"></script>

	<script id="shader-vs" type="x-shader/x-vertex">
	attribute vec3 aVertexPosition;
	attribute vec2 aBezierCoord;

	module Elmz.Signal where

	import Elmz.Maybe

	{-\| Delay the input `Signal` by one unit. -}
	delay : a -> Signal a -> Signal a
	delay h s =
	let go a {prev,cur} = { cur = prev, prev = a }
	in foldp go { prev = h, cur = h } s
	\|> lift .cur

	import Color (Color, rgb)
	import Graphics.Collage (..)
	import Graphics.Element (Element)
	import List ((::), map)
	import Signal (Signal, foldp, (<~), sampleOn)
	import Keyboard (arrows)
	import Time (millisecond, every)

	--------------------------

	parallel : Address a -> List (Task error a) -> Task error (List ThreadID)
	parallel address tasks =
	let
	sendToAddress task = spawn (task `andThen` send address)
	in
	sequence (List.map sendToAddress tasks)

	defmodule MyApp do
	use Application

	def start(_type, _args) do
	import Supervisor.Spec, warn: false

	children = [
	Plug.Adapters.Cowboy.child_spec(:http, MyApp.Router, [], [
	dispatch: dispatch
	])

	/! (c) 2016 Andrea Giammarchi - MIT Style License /

	// simple state-like objects handler
	// based on prototypal inheritance

	function State() {'use strict';}

	// States are serializable dictionaries
	// toJSON and toString are the only reserved keywords
	// every other name can be used as name (included __proto__)