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

Handling package and class scopes in Unicon

Creating symbol tables for Jzero considers two scopes: class and local. Since Jzero does not do instances, Jzero's class scope is static and lexical. A larger, real-world language has to do more work to handle scopes. Java, for example, has to distinguish when a symbol declared in the class scope is a reference to a variable shared across all instances of the class, and when the symbol is a normal member variable that's been allocated separately for each instance of the class. In the case of Jzero, an isMember Boolean can be added to the symbol table entries to distinguish member variables from class variables, similar to the isConst flag.

Unicon's implementation is a lot different than Jzero's. A summary of its symbol tables and class scopes allows for a fruitful comparison. Whatever it does similarly to Jzero might also be how other languages handle things. What Unicon does differently than Jzero, each language might...