Reactive Programming

as reactive as possible by Vyacheslav Goldenshteyn

OOP as

FP as

Mutually exclusive ways?

Complimentary!

            stream a, b, c
            c := a + b
            a.set(2)
            b.set(4)
            print c // prints 6
            b.set(2)
            print c // prints 4

Just observer

Welcome to the real world

Event-driven problems:

Lots of listeners
Adding and removing them a lot
Lack of readability
Memory leaks
Unfriendly debug

Ooops!!!

Be reactive!

            val trimmedName = map(nameInput.text(), String::trim)
            val trimmedSurname = map(surnameInput.text(), String::trim)
            val rawEmail = reduce(trimmedName,
                       trimmedSurname,
                       {f, s -> "$f.$s@$EMAIL_DOMAIN"})
            val validEmail = filter(rawEmail, ::validateEmail, "")
            val status = map(rawEmail, ::validateEmail)
            bind(emailInput.text(), validEmail)
            bind(okButton.enabled(), status)