Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Features
Speaker Deck
PRO
Sign in
Sign up for free
Search
Search
Let's talk about PureScript
Search
Kārlis Lauva
August 17, 2016
Programming
0
78
Let's talk about PureScript
Presentation at Frontend Meetup Riga, August 2016.
Kārlis Lauva
August 17, 2016
Tweet
Share
More Decks by Kārlis Lauva
See All by Kārlis Lauva
Going Full Monty with full.monty
karlis
1
93
The Transatlantic Struggle
karlis
0
66
Two Scoops of Scala
karlis
0
100
Valsts pārvaldes atvērto datu semantiskās integrācijas procesi
karlis
1
180
Tornado in 1 Hour (or Less)
karlis
4
190
Other Decks in Programming
See All in Programming
Railsだからできる 例外業務に禍根を残さない 設定設計パターン
ei_ei_eiichi
0
930
ALL CODE BASE ARE BELONG TO STUDY
uzulla
25
6.2k
What's new in Spring Modulith?
olivergierke
1
160
Foundation Modelsを実装日本語学習アプリを作ってみた!
hypebeans
0
120
はじめてのDSPy - 言語モデルを『プロンプト』ではなく『プログラミング』するための仕組み
masahiro_nishimi
2
560
Android16 Migration Stories ~Building a Pattern for Android OS upgrades~
reoandroider
0
120
私はどうやって技術力を上げたのか
yusukebe
44
19k
Go言語の特性を活かした公式MCP SDKの設計
hond0413
1
240
デミカツ切り抜きで面倒くさいことはPythonにやらせよう
aokswork3
0
250
What Spring Developers Should Know About Jakarta EE
ivargrimstad
0
190
The Past, Present, and Future of Enterprise Java
ivargrimstad
0
400
bootcamp2025_バックエンド研修_WebAPIサーバ作成.pdf
geniee_inc
0
110
Featured
See All Featured
Site-Speed That Sticks
csswizardry
13
910
How to Think Like a Performance Engineer
csswizardry
27
2k
Statistics for Hackers
jakevdp
799
220k
How STYLIGHT went responsive
nonsquared
100
5.8k
Building Adaptive Systems
keathley
44
2.8k
Code Review Best Practice
trishagee
72
19k
Context Engineering - Making Every Token Count
addyosmani
7
260
Automating Front-end Workflow
addyosmani
1371
200k
Into the Great Unknown - MozCon
thekraken
40
2.1k
CSS Pre-Processors: Stylus, Less & Sass
bermonpainter
359
30k
Mobile First: as difficult as doing things right
swwweet
225
10k
Intergalactic Javascript Robots from Outer Space
tanoku
273
27k
Transcript
an exciting trip through history prelude
1936 Lambda Calculus is born
1990 A bunch of smart people start working Haskell
1995 Brendan Eich is hired by NetScape to write Scheme
for the browser
Spoiler alert: He doesn't write a Scheme for NetScape
2016
You shouldn't be sad.
Maybe those functional dudes got something right.
let's talk about purescript Kārlis Lauva @skazhy frontend rīga meetup,
2016
Hello. I write Clojure and dabble with other things This
is not a monad tutorial This is, like, my opinion
So, Haskell for the browser, eh
module Main where import Prelude import Control.Monad.Eff import Control.Monad.Eff.Console sup
:: String -> String sup g = "sup, " ++ g main :: forall e. Eff (console :: CONSOLE | e) Unit main = do log $ sup "world"
None
(function(exports) { "use strict"; var Prelude = PS["Prelude"]; var Control_Monad_Eff
= PS["Control.Monad.Eff"]; var Control_Monad_Eff_Console = PS["Control.Monad.Eff.Console"]; var sup = function (g) { return "sup, " + g; }; var main = Control_Monad_Eff_Console.log(sup("world")); exports["main"] = main; exports["sup"] = sup;; })(PS["Main"] = PS["Main"] || {}); PS["Main"].main();
Y
turns out, functional programming languages are really useful for web
things
but javascript too can be purely functional
None
let's discuss the bad parts
[Object object]
an *actual* type system
purescript makes this example boring
like, really boring
sketchy branching
None
None
pattern matching
data Behavior = KillHumans | BeNiceToHumans type Robot = {
naughty :: Boolean } interactWithHumans :: Robot -> Behavior interactWithHumans { naughty: true } = KillHumans interactWithHumans { naughty: false } = BeNiceToHumans
data Behavior = KillAllHumans | BeNiceToHumans | KillOnlyVapers type Robot
= { niceness :: Int } interactWithHumans :: Robot -> Behavior interactWithHumans { niceness: 0 } = KillAllHumans interactWithHumans { niceness: 1 } = KillOnlyVapers interactWithHumans _ = BeNiceToHumans
callback hell
monads
fetchRobots(function(response) { assembleFleet(function(robots) { if (robots) return robots; }, function(error
{ .. }); }, function(error) {... });
data RobotArmy = Army (List Robot) fetchRobots = do robotParts
<- get "/robotParts" robots <- assembleFleet robotParts return $ Army robots
None
does purescript survive in the real world?
yes.
None
ecosystem and tooling
psc short for "purescript compiler"
modules managed via bower
• build tool => pulp • hoogle for purescript =>
pursuit
purescript - javascript teamwork
back to killer robots
data Behavior = KillHumans | BeNiceToHumans instance showBehavior :: Show
Behavior where show KillHumans = "kill all humans11" show BeNiceToHumans = "humans, you are pretty tite" type Robot = { naughty :: Boolean } interactWithHumans :: Robot -> Behavior interactWithHumans { naughty: true } = KillHumans interactWithHumans { naughty: false } = BeNiceToHumans safeInteract :: Boolean -> String safeInteract x = show $ interactWithHumans { crazyMurderer : x }
PS.Main.safeInteract(isCrazyMurderingRobot)();
but will purescript react?
yes.
ok, so what have we learned
so should we all switch to purescript today?
not _all_ of us
most of the internet runs on vanilla javascript just fine
(for years)
None
None
go check it out hack cool things
• purescript.org • karlis.me
thanks