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

Debugging and testing your syntax tree

The trees that you build must be rock solid. What this spectacular mixed metaphor means is: if your syntax tree structure is not built correctly, you can't expect to be able to build the rest of your programming language. The most direct way of testing that the tree has been constructed correctly is to walk back through it and look at the tree that you have built. This section contains two examples of doing that. You will print your tree first in a human-readable (more or less) ASCII text format, then you will learn how to print it out in a format that is easily rendered graphically using the popular open source Graphviz package, commonly accessed through PlantUML or the classic command-line tool called dot. First, consider some of the most common causes of problems in syntax trees.

Avoiding common syntax tree bugs

The most common problems with syntax trees result in program crashes when you print the tree out. Each tree node may hold...