Book Image

Learning D

By : Michael Parker
Book Image

Learning D

By: Michael Parker

Overview of this book

D is a modern programming language that is both powerful and efficient. It combines multiple paradigms in a way that opens up a whole new world of software design. It is used to develop both desktop and web applications, with future targets including mobile, and is available on multiple platforms. It is familiar to anyone with some experience in one or more of the C-family languages. However, hidden in the similarities are several differences that can be surprising when trying to apply common idioms from other languages. When learning D on your own, this can make it more time-consuming to master. In order to make the most of the language and become an idiomatic D programmer, it’s necessary to learn how to think in D. This book familiarizes you with D from the ground up, with a heavy focus on helping you to avoid surprises so that you can take your D knowledge to the next level more quickly and painlessly. Your journey begins with a taste of the language and the basics of compiling D programs with DMD, the reference D compiler developed by Digital Mars, and DUB, a community-developed build utility and package manager. You then set out on an exploration of major language features. This begins with the fundamentals of D, including built-in types, conditionals, loops and all of the basic building-blocks of a D program, followed by an examination of D’s object-oriented programming support. You’ll learn how these features differ from languages you may already be familiar with. Next up are D’s compile-time features, such as Compile-Time Function Evaluation and conditional compilation, then generic programming with templates. After that, you’ll learn the more advanced features of ranges and functional pipeline programming. To enhance your D experience, you are next taken on a tour of the D ecosystem and learn how to make D interact with C. Finally, you get a look at D web development using the vibe.d project and the book closes with some handy advice on where to go next.
Table of Contents (19 chapters)
Learning D
About the Author
About the Reviewers

Compile-time strings

Literals, const and immutable variables in module scope (that aren't initialized in a static constructor), static const and immutable variables in function scope, and manifest constants and enum members, can all be known at compile time. In this section, the focus is specifically on compile-time strings. We're first going to see one more way to initialize them, then we'll see how any compile-time string can be used to generate code.

The import expression

The import expression is quite different from the import declaration that pulls module symbols into the current scope. This expression is used to specify any file name for the compiler to read into memory at compile time. The file will be read as text and treated as a string literal, making it possible to assign it to any variable that can be initialized at compile time.

import std.stdio;
immutable fileData1 = import("myfile1.txt");
enum fileData2 = import("myfile2.txt");
void main() {