Build Your Own Programming Language

Clinton L. Jeffery, creator of the Unicon programming language, shows readers how to implement their own languages. Custom languages can lower the cost and speed up the schedule of building software for emerging or niche fields, and many developers now prefer languages tailored to one problem area over general-purpose ones. Designing a language of your own can also be a way to push back against the growing bulk and intricacy of modern software.

The book starts with the front end of a compiler, covering lexical analysis and parsing. Readers then work through a sequence of passes over the syntax tree, ending with bytecode generation for a virtual machine. Next, it explains why features suited to a specialized domain are often better built into the language as operators and functions than supplied as library routines. The final section addresses memory management, covering reference counting and mark-and-sweep garbage collection.

Jeffery draws on his experience building Unicon to add context to the concepts. Examples appear in both Unicon and Java, so readers can follow whichever suits them, whether a high-level language with advanced features or a mainstream one. By the end, readers should be able to build, deploy, and run their own domain-specific languages that compile and execute programs.

The book is intended for software developers who want to invent a language or create a specialized one. It also suits computer science students in compiler courses who want a practical companion to more theoretical textbooks. Readers are expected to have intermediate experience with a high-level language such as Java or C++.