chapter 1 n IntroductIon
2
The Genesis of F#
F# began in 2002, when Don Syme and others at Microsoft Research decided to ensure that the ML approach
to pragmatic but theoretically based language design found a high-quality expression for the .NET platform.
The project was closely associated with the design and implementation of Generics for the .NET Common
Language Runtime. The first stabilized, supported version of F# was F# 2.0, included with Visual Studio 2010.
In 2012, Microsoft released F# 3.0. This is the version of the language described in this book and is also the
version included with Visual Studio 2012.
F# shares a core language with the programming language OCaml, which in turn comes from the ML
family of programming languages, which dates back to 1974. F# also draws from Haskell, particularly with
regard to two language features: sequence expressions and workflows.
Despite the similarities to OCaml and Haskell, programming with F# is quite different in practice. In
particular, the F# approach to OO programming, and dynamic language techniques is substantially
different from other mainstream functional languages. Programming in F# tends to be more object-
oriented than in other functional languages. Programming also tends to be more flexible, as F# embraces
techniques such as dynamic loading, dynamic typing, and reflection, and it adds techniques such as
expression quotation, units-of-measure, type providers and active patterns. We cover these topics in this
book and use them in many application areas.
F# also owes a lot to the designers of .NET, whose vision of language interoperability between C++,
Visual Basic, and the language that eventually became C# is still shaping the computer industry. Today, F#
draws much from the broader community around the Common Language Infrastructure (CLI),
implemented by the Microsoft .NET Framework and Mono. F# is able to leverage libraries and techniques
developed by Microsoft, the broader .NET community, the highly active open source community centered
around Mono, and open source and cross-platform implementation of the ECMA CLI standard that works
well on Windows, Mac, and Linux environments. Mono can also be used to author applications for the
Android and Apple iOS platforms. F# code can also be edited and executed directly in most web browsers
through sites such as
www.tryfsharp.org. F# 3.0 can be compiled to Javascript through the open-source
community project Pit and the professional open-source product WebSharper,
www.websharper.com.
About This Book
This book is structured in three parts. Chapters 2 to 11 deal with the F# language and basic techniques
such as functional, imperative and object-oriented programming, techniques to program with textual,
structured and numeric data, and techniques for parallel, reactive and concurrent programming. Chapters
12 to 20 deal with a series of applied programming samples and topics ranging from building applications
to software engineering and design issues.
Throughout this book, we address both programming constructs and programming techniques. Our
approach is driven by examples: we show code, and then we explain it. Frequently, we give reference
material describing the constructs used in the code and related constructs you may use in similar
programming tasks. We’ve found that an example-driven approach helps bring out the essence of a
language and how the language constructs work together. You can find a complete syntax guide in the
appendix, and we encourage you to reference it while reading the book.
The book’s chapters are as follows, starting with basic F# techniques:
Chapter 2, “Your First F# Program – Getting Started With F#,” begins by
introducing F# Interactive, a tool you can use to interactively evaluate F#
expressions and declarations and that we encourage you to use while reading this
book. In this chapter, you use F# Interactive to explore some basic F# and .NET
constructs, and we introduce many concepts that are described in more detail in
later chapters.
yytravis2014-09-03讲的比较深入和全面
