The functional reactive nature of Marble.js

Follow us @boldarecom @JOZFLAKUS The functional reactive nature of marble.js

Follow us @boldarecom @JOZFLAKUS Józef Flakus Senior JavaScript developer

@JOZFLAKUS Ord, Setoid, Semigroup, Foldable, Monoid, Applicative, Contravariant, Functor, Bifunctor,
Profunctor, Monad ...

@JOZFLAKUS Functional programming is not only about Category Theory

@JOZFLAKUS #1 Pure functions f(x) = x + 1

@JOZFLAKUS f(x) = x + 1 ---------------------------------------------------- f(2) = 3
#2 Referential transparency

@JOZFLAKUS Immutability const x = { foo: ‘bar’ } const
y = x X.foo = ‘baz’ y.foo === #3

@JOZFLAKUS add :: Number -> Number -> Number ----------------------------------- const
add = x => y => x + y ----------------------------------- const sum = add(2)(3) First-class functions #4

@JOZFLAKUS const length = ([x, ...xs], len = 0) =>
def(x) ? length(xs, len + 1) : len Recursion #5

@JOZFLAKUS People are finally hearing about functional programming again

reactive

@JOZFLAKUS

@JOZFLAKUS mergeMap, concatMap, switchMap, exhaust, buffer, bufferCount, multicast, pairwise, takeUntil,
takeWhile, withLatestFrom, zip, pluck, publishLast, skipWhile …

@JOZFLAKUS Reactive programming is programming with asynchronous data streams... 1
2 3

@JOZFLAKUS … and you can do with streams whatever you
imagine 1 2 3 map(x => 10 * x) 10 20 30

@JOZFLAKUS callbacks promises async/await observables

@JOZFLAKUS Functional reactive programming

@JOZFLAKUS A functional reactive Node.js framework for building server-side applications

@JOZFLAKUS Based on RxJS library

@JOZFLAKUS TypeScript users as a main target

@JOZFLAKUS Since version 2.0 it acts like a framework

@JOZFLAKUS Build REST/event based APIs with ease

@JOZFLAKUS open source

@JOZFLAKUS #1 RxJS like a hammer for expressing asynchronous flow

@JOZFLAKUS #2 Monadic manner

@JOZFLAKUS #3 Everything is a stream

@JOZFLAKUS #4 Effect as a main building block

@JOZFLAKUS #5 Referential transparent program specification

@JOZFLAKUS #6 Everything is just a function

Not only basic HTTP protocol

@JOZFLAKUS WebSockets

Pure functional programming patterns in mind

@JOZFLAKUS Dependency Injection

Type safety as a main goal

@JOZFLAKUS Type safety #1

@JOZFLAKUS Type safety #2

@JOZFLAKUS Why should I care?

@JOZFLAKUS 1# Easy to test

@JOZFLAKUS 2# Easy to read ;-) and reason about

@JOZFLAKUS 3# Avoid confusing problems and errors in code

@JOZFLAKUS 4# Really fun to write!

@JOZFLAKUS 5# Da future, man!

@JOZFLAKUS github.com/marblejs

@JOZFLAKUS twitter.com/marble_js

@JOZFLAKUS docs.marblejs.com

@JOZFLAKUS Sometimes, the elegant implementation is just a function. Not
a method. Not a class. Just a function. ~ John Carmack >

@JOZFLAKUS See you on the Mars!

@boldarecom

The functional reactive nature of Marble.js

The functional reactive nature of Marble.js

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