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
Functional Reactive Programming
Search
Oscar Swanros
February 18, 2015
Programming
1
100
Functional Reactive Programming
Functional Reactive Programming 101.
Oscar Swanros
February 18, 2015
Tweet
Share
More Decks by Oscar Swanros
See All by Oscar Swanros
Applied Concurrency: NOT from the ground up
oscarswanros
0
93
Lessons From Becoming an SDK Developer
oscarswanros
0
62
Objective-C & Swift: Interoperability Tips and Tricks
oscarswanros
0
150
What Lies Under The Syntax Sugar
oscarswanros
0
220
Apps Para iOS: De Diseño a Implementación
oscarswanros
0
80
Becoming a Better iOS Developer Through Tooling
oscarswanros
0
2.8k
Mejores Prácitcas Para el Desarrollo de Aplicaciones iOS con Swift
oscarswanros
0
120
Architecting iOS Apps for Fun & Profit
oscarswanros
0
190
Android Elements & Design Patterns
oscarswanros
0
67
Other Decks in Programming
See All in Programming
What's new in Spring Modulith?
olivergierke
1
160
タスクの特性や不確実性に応じた最適な作業スタイルの選択(ペアプロ・モブプロ・ソロプロ)と実践 / Optimal Work Style Selection: Pair, Mob, or Solo Programming.
honyanya
3
180
いま中途半端なSwift 6対応をするより、Default ActorやApproachable Concurrencyを有効にしてからでいいんじゃない?
yimajo
2
450
Go言語はstack overflowの夢を見るか?
logica0419
0
510
Writing Better Go: Lessons from 10 Code Reviews
konradreiche
2
5k
AI Coding Meetup #3 - 導入セッション / ai-coding-meetup-3
izumin5210
0
3.4k
pnpm に provenance のダウングレード を検出する PR を出してみた
ryo_manba
1
110
20251016_Rails News ~Rails 8.1の足音を聴く~
morimorihoge
2
650
CSC305 Lecture 09
javiergs
PRO
0
300
Flutterで分数(Fraction)を表示する方法
koukimiura
0
140
なぜあの開発者はDevRelに伴走し続けるのか / Why Does That Developer Keep Running Alongside DevRel?
nrslib
3
410
One Enishi After Another
snoozer05
PRO
0
140
Featured
See All Featured
Building Adaptive Systems
keathley
44
2.8k
Let's Do A Bunch of Simple Stuff to Make Websites Faster
chriscoyier
508
140k
Agile that works and the tools we love
rasmusluckow
331
21k
Reflections from 52 weeks, 52 projects
jeffersonlam
353
21k
Build your cross-platform service in a week with App Engine
jlugia
232
18k
Keith and Marios Guide to Fast Websites
keithpitt
411
23k
How to train your dragon (web standard)
notwaldorf
97
6.3k
Templates, Plugins, & Blocks: Oh My! Creating the theme that thinks of everything
marktimemedia
31
2.5k
Exploring the Power of Turbo Streams & Action Cable | RailsConf2023
kevinliebholz
36
6.1k
Designing for humans not robots
tammielis
254
26k
Writing Fast Ruby
sferik
629
62k
Why Our Code Smells
bkeepers
PRO
340
57k
Transcript
Func%onal)Reac%ve)Programming Oscar&Swanros MobileCoder.mx mobilecoder.mx,-2015 1
@Swanros h"p:/ /swanros.com mobilecoder.mx,-2015 2
I"got"bored. mobilecoder.mx,-2015 3
Un#l... mobilecoder.mx,-2015 4
WWDC$'14 mobilecoder.mx,-2015 5
I'm$running$away$from$OOP$and$the$ MVC$pa9ern. mobilecoder.mx,-2015 6
And$also$a$li*le$bit$ of... mobilecoder.mx,-2015 7
typedef (^myBlock)(BOOL isThisCool) = ^void() { // }; mobilecoder.mx,-2015 8
Callback'hell,'anyone? mobilecoder.mx,-2015 9
Because'it'gets'boring'quickly... ! mobilecoder.mx,-2015 10
Enter&FRP. mobilecoder.mx,-2015 11
Func%onal)Reac%ve)Programming = Func%onal)Programming)+)Reac%ve)Programming mobilecoder.mx,-2015 12
Func%onal)Programming In#a#purely'func+onal#language,#f(x)#will#return#the#same#value#for# the#same#x. Always. mobilecoder.mx,-2015 13
Reac%ve'Programming In#a#reac%ve#language,#y=f(x) y!will!always!stay!up!to!date!when!x! changes. mobilecoder.mx,-2015 14
mobilecoder.mx,-2015 15
FRP!is!about!datatypes!that! represent!a!value!over!&me. mobilecoder.mx,-2015 16
At#the#core#of#FRP#are#Signals. mobilecoder.mx,-2015 17
A"Signal"is"a"value"that"changes"over()me. mobilecoder.mx,-2015 18
done := make(chan bool) watcher := notificator.New() for { select
{ case newText := <-watcher.Next: fmt.Println(newText) case error := <-watcher.Error: log.Fatal(error) } } <-done mobilecoder.mx,-2015 19
[self.emailTextField.rac_textSignal subscribeNext:^(id value) { NSLog(@"%@", value); }]; mobilecoder.mx,-2015 20
mobilecoder.mx,-2015 21
@interface ViewController()<UITextFieldDelegate> // ... self.emailTextField.delegate = self; // ... -(BOOL)textField:(UITextField
*)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)string { NSLog(@"%@", [textField.text stringByAppendingString:string]); return YES; } mobilecoder.mx,-2015 22
[self.emailTextField.rac_textSignal subscribeNext:^(id value) { NSLog(@"%@", value); }]; mobilecoder.mx,-2015 23
// 1 RACSignal *usernameTextSignal = self.usernameTextField.rac_textSignal; RACSignal *passwordTextSignal = self.passwordTextField.rac_textSignal;
// 2 RACSignal *validUsernameSignal = [[usernameTextSignal map:^id(NSString *username) { return @([self isValidUsername:username]); }] distinctUntilChanged]; RACSignal *validPasswordSignal = [[passwordTextSignal map:^id(NSString *password) { return @([self isValidPassword:password]); }] distinctUntilChanged]; // 3 RAC(self.usernameTextField, backgroundColor) = [validUsernameSignal map:^id(NSNumber *usernameValid) { return [usernameValid boolValue] ? [UIColor greenColor] : [UIColor redColor]; }]; RAC(self.passwordTextField, backgroundColor) = [validPasswordSignal map:^id(NSNumber *passwordValid) { return [passwordValid boolValue] ? [UIColor greenColor] : [UIColor redColor]; }]; // 4 [[RACSignal combineLatest:@[validUsernameSignal, validPasswordSignal] reduce:^id(NSNumber *usernameValid, NSNumber *passwordValid){ return @([usernameValid boolValue] == YES && [passwordValid boolValue] == YES); }] subscribeNext:^(NSNumber *loginButtonActive) { self.loginButton.enabled = [loginButtonActive boolValue]; }]; mobilecoder.mx,-2015 24
mobilecoder.mx,-2015 25
Func%onal)Reac%ve)Programming)lets)you)be)more)concise)with)your)code. mobilecoder.mx,-2015 26
Focus&on&what&you&want&to&do, and$not$on$how$to$do$it. mobilecoder.mx,-2015 27
(That's(the(Func.onal(mo#o.) mobilecoder.mx,-2015 28
Resources? mobilecoder.mx,-2015 29
Ruby:&frapuccino class Button def push emit(:pushed) end end button =
Button.new stream = Frappuccino::Stream.new(button) counter = stream .map {|event| event == :pushed ? 1 : 0 } .inject(0) {|sum, n| sum + n } counter.now # => 0 button.push counter.now # => 1 mobilecoder.mx,-2015 30
JS:$RxJS var source = getStockData(); source .filter(function (quote) { return
quote.price > 30; }) .map(function (quote) { return quote.price; }) .forEach(function (price) { console.log('Prices higher than $30: $' + price); }); mobilecoder.mx,-2015 31
Learning(FRP(is(hard. mobilecoder.mx,-2015 32
But$it's$worth$it. mobilecoder.mx,-2015 33
Ques%ons? mobilecoder.mx,-2015 34