Adventures in Elm GOTO Chicago, 24 May 2016 Adventures in Elm - PowerPoint PPT Presentation

Adventures in Elm GOTO Chicago, 24 May 2016

Adventures in Elm Events, Reproducibility, and Kindness question your principles

@jessitron Adventures in Elm Events, Reproducibility, and Kindness

Data Data In Out

Server UI

Everything My that Dream matters Appearance

JavaScript + React + Redux ClojureScript + Om Scala.js + React

language architecture system

undefined is not a function

“I tried over and over again to turn my self doubt into a pure functional program, and eventually, it clicked.” @mrb_bk

substring : Int -> String -> String substring qty string = … locationCode : String -> String locationCode = substring 3 peelerLocation : String peelerLocation = substring 3 "STL-48" locations : List String locations = ["STL", "ORD"]

peelerLocation : String peelerLocation = substring 3 "STL-48" peelerLocation = "STL-48" |> substring 3

g type alias LocationCode = String n i m a n locationCode : String -> String locationCode = substring 3 peelerLocation : String peelerLocation = "STL-48" |> substring 3 locations : List String locations = ["STL", "ORD"]

g type alias LocationCode = String n i m a n locationCode : String -> LocationCode locationCode = substring 3 peelerLocation : LocationCode peelerLocation = "STL-48" |> substring 3 locations : List LocationCode locations = ["STL", "ORD"]

type alias Machine = { locationCode : LocationCode records , number : Int } myPeeler : Machine myPeeler = { locationCode = "STL" , number = 48 }

expressions type alias Machine = { locationCode : LocationCode , number : Int } parse : String -> Machine parse s = let location = locationCode s num = … in { locationCode = location , number = num }

new type! type MachineDatum = Location LocationCode | Number Int machineData : List MachineDatum machineData = [ Location "STL" constructors! , Number 48 ]

pattern matching! type MachineDatum = Location LocationCode | Number Int describe : MachineDatum -> String describe datum = case datum of Location code -> "in " ++ code Number n -> "number " ++ (toString n)

Hello World

Evan Czaplicki

Hello Mouse

Hello Deeter

Deeter Clicks

model update view

small pieces encapsulated

natural extensible

server compiler package manager test tools build tools editors libraries learning community

https://derpiboo.ru/720277

elm-lang.org @jessitron http://guide.elm-lang.org/ github.com/jessitron/elm-hello-wrold github.com/satellite-of-love/landscape

modules: explicit exports, explicit dependencies packages: required docs, enforced semantic versioning types: parameterized types, type inference, aliases, unions, records

points about elm: evolution - target audience (Everyone) - narrow objective (target experience) - language system (experience) - explicitness -

what this changes: structure (framework) - larger components - global state: components can call each - others' functions standards for my experience -

predictability: reproducibility of event model - deterministic dispatch - versioning guarantees -

Explicitness Evolution Event-based Enlightenment

http://javkiller.deviantart.com/art/Library-colors-243633627 http://strachattack.deviantart.com/art/Queen-Chrysalis-493886766 http://ohemo.deviantart.com/art/Evolved-Chrysalis-493427839 http://mlp.wikia.com/wiki/Canterlot/Gallery