Book Image

Build Your Own Programming Language

By : Clinton L. Jeffery
Book Image

Build Your Own Programming Language

By: Clinton L. Jeffery

Overview of this book

The need for different types of computer languages is growing rapidly and developers prefer creating domain-specific languages for solving specific application domain problems. Building your own programming language has its advantages. It can be your antidote to the ever-increasing size and complexity of software. In this book, you’ll start with implementing the frontend of a compiler for your language, including a lexical analyzer and parser. The book covers a series of traversals of syntax trees, culminating with code generation for a bytecode virtual machine. Moving ahead, you’ll learn how domain-specific language features are often best represented by operators and functions that are built into the language, rather than library functions. We’ll conclude with how to implement garbage collection, including reference counting and mark-and-sweep garbage collection. Throughout the book, Dr. Jeffery weaves in his experience of building the Unicon programming language to give better context to the concepts where relevant examples are provided in both Unicon and Java so that you can follow the code of your choice of either a very high-level language with advanced features, or a mainstream language. By the end of this book, you’ll be able to build and deploy your own domain-specific languages, capable of compiling and running programs.
Table of Contents (25 chapters)
1
Section 1: Programming Language Frontends
7
Section 2: Syntax Tree Traversals
13
Section 3: Code Generation and Runtime Systems
21
Section 4: Appendix

Chapter 1: Why Build Another Programming Language?

This book will show you how to build your own programming language, but first, you should ask yourself, why would I want to do this? For a few of you, the answer will be simple: because it is so much fun. However, for the rest of us, it is a lot of work to build a programming language, and we need to be sure about it before we make a start. Do you have the patience and persistence that it takes?

This chapter points out a few good reasons for building your own programming language, as well as some situations where you don't have to build your contemplated language; after all, designing a class library for your application domain might be simpler and just as effective. However, libraries have their downsides, and sometimes only a new language will do.

After this chapter, the rest of this book will, having considered things carefully, take for granted that you have decided to build a language. In that case, you should determine some of the requirements for your language. But first, we're going to cover the following main topics in this chapter:

  • Motivations for writing your own programming language
  • The difference between programming languages and libraries
  • The applicability of programming language tools to other software projects
  • Establishing the requirements for your language
  • A case study that discusses the requirements for the Unicon language

Let's start by looking at motivations.