February 2018
Intermediate to advanced
350 pages
7h 35m
English
Content preview from Functional Kotlin
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Optics
Optics are abstractions to update immutable data structures elegantly. One form of optics is Lens (or lenses, depending on the library implementation). A Lens is a functional reference that can focus (hence the name) into a structure and read, write, or modify its target:
typealias GB = Intdata class Memory(val size: GB)data class MotherBoard(val brand: String, val memory: Memory)data class Laptop(val price: Double, val motherBoard: MotherBoard)fun main(args: Array<String>) { val laptopX8 = Laptop(500.0, MotherBoard("X", Memory(8))) val laptopX16 = laptopX8.copy( price = 780.0, motherBoard = laptopX8.motherBoard.copy( memory = laptopX8.motherBoard.memory.copy( size = laptopX8.motherBoard.memory.size * 2 ) ) ) println("laptopX16 = ...
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O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.