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

Using UFlex and JFlex

Writing a scanner by hand is an interesting task for a programmer who wants to know exactly how everything works, but it will slow down the development of your language and make it more difficult to maintain the code afterward.

Good news, everyone! A family of tools descended from UNIX, known as lex, takes regular expressions and generates a scanner function for you. Lex-compatible tools are available for most popular programming languages. For C/C++, the most widely used lex-compatible tool is Flex, hosted at https://github.com/westes/flex/. For Unicon, we use UFlex, while for Java, you can use JFlex. These tools may have various custom extensions, but to the extent that they are compatible with UNIX lex, we can present them together as one language for writing scanners. This book's examples have been crafted carefully so that we can even use the same lex input for both the Unicon and Java implementation!

The input files for lex are often called (lex...