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

Analyzing syntax

As a programmer, you are probably already familiar with syntax error messages and the general idea of syntax, which is to understand what kinds of words or lexemes must appear, in what order, for a given communication to be well formed in a language. Most human languages are picky about this, while a few are more flexible about word order. Fortunately, most programming languages are far simpler and more restrictive than natural human languages about what constitutes a legal input.

The input for syntax analysis consists of the output of the previous chapter on lexical analysis. Communication, such as a message or a program, is broken down into a sequence of component words and punctuation. This could be an array or list of token objects, although for parsing, all the algorithm requires is the sequence of integer codes returned from calls to yylex(), one after another. It is the job of syntax analysis to determine whether the communication, in a given language, such...