Programming in Scala (Third Edition)

This book is one of the authoritative tutorials and references on the Scala language, co-authored by Martin Odersky, the creator of Scala, together with Lex Spoon and Bill Venners; the Chinese edition is translated by Gao Yuxiang, long engaged in promoting and translating Scala. The book addresses developers with some programming experience and proceeds step by step: it begins with a small program that can be written in a few lines, giving readers a quick feel for Scala; it then moves in turn through classes and objects, basic types and operations, functions and closures, control abstraction, composition and inheritance, traits, packages and imports, assertions and tests, and case classes and pattern matching. After the language basics, the book discusses lists and other collection classes, mutable objects, type parameterization, abstract members, implicit conversions and implicit parameters, the implementation of lists, for expressions, the Scala collections architecture, extractors, annotations, XML processing, modular programming with objects, object equality, and interoperability between Scala and Java, closing with futures and concurrent programming, combinator parsing, GUI programming, and a complete spreadsheet (SCells) case study that shows how to combine these features to build real programs. The third edition is updated for Scala 2.12 and adds string interpolation, futures and concurrency (including methods new in 2.12 and asynchronous testing in ScalaTest 3.0), wildcard types, advice on writing hashCode, deep integration of Scala 2.12 with Java 8 (such as implementing SAM types with function literals), implicit classes, custom AnyVal, and context-bound syntax for type classes. Throughout, the book emphasizes why the language is designed as it is, helping readers not only write Scala but understand the motivations behind its trade-offs; its functional and object-oriented ideas are valuable even to readers who do not use Scala directly.