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

Checking structured type accesses

In this book, the phrase structured type will denote composite objects that can hold a mixture of types whose elements are accessed by name. This contrasts with arrays, whose elements are accessed by their position and whose elements are of the same type. In some languages, there are struct or record types for this kind of data. In Jzero and most object-oriented languages, classes are used as the principal structured type.

This section discusses aspects of how to check the types for operations on classes and, more specifically, class instances. This organization mirrors the presentation of array types at the beginning of this chapter, starting with what is needed to process declarations of class variables.

The original intent of Jzero was to support a tiny Java subset that was somewhat comparable to Wirth's PL/0 language. Such a language does not require class instances or object-orientation, and space limitations prevent us from covering...