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 2: Programming Language Design

Before trying to build a programming language, you need to define it. This includes the design of the features of the language that are visible on its surface, including basic rules for forming words and punctuation. This also includes higher-level rules, called syntax, that govern the number and order of words and punctuation in larger chunks of programs, such as expressions, statements, functions, and programs. Language design also includes the underlying meaning, also known as semantics.

Programming language design often begins by writing example code to illustrate each of the important features of your language, as well as show the variations that are possible for each construct. Writing examples with a critical eye lets you find and fix many possible inconsistencies in your initial ideas. From these examples, you can then capture the general rules that each language construct follows. Write down sentences that describe your rules as you...