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

Learning about trees

Mathematically a tree is a kind of graph structure; it consists of nodes and edges that connect those nodes. All the nodes in a tree are connected. A single node at the top is called the root. Tree nodes can have zero or more children, and at most one parent. A tree node with zero children is called a leaf; most trees have a lot of leaves. A tree node that is not a leaf has one or more children and is called an internal node. The following diagram shows an example tree with a root, two additional internal nodes, and five leaves:

Figure 5.1 – A tree with a root, internal nodes, and leaves

Trees have a property called arity that says what the maximum number of children a node can have is. An arity of 1 would give you a linked list. Perhaps the most common kinds of trees are binary trees (arity = 2). The kind of trees we need has as many children as there are symbols on the right-hand side of the rules in our grammar; these are so-called...