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

Forming syntax trees for the Jzero language

This section shows you how to build syntax trees for the Jzero language. The full j0gram.y file for this chapter is available on the book's GitHub site. The header is omitted here since the %token declarations are unchanged from how they appear in the section titled The Jzero Yacc specification in the previous chapter. Although we are again presenting many of the grammar rules shown in the last chapter, the focus now is on the construction of new tree nodes associated with each production rule, if any.

As described earlier, the tree's internal nodes are constructed in semantic actions that are added at the ends of production rules. For each production rule that builds a new node, it is assigned to $$, the yacc value corresponding to the new non-terminal symbol built by that production rule.

The starting non-terminal, which in the case of Jzero is a single class declaration, is the point at which the root of the entire tree...