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

Writing a runtime system for Jzero

In a programming language implementation, the runtime system is the code that is included to provide basic functionalities needed for the generated code to run. Generally, the higher level the language is and the greater its distance from the underlying hardware, the larger the runtime system. The Jzero runtime system is as small as possible; it only supports a few internal helper functions such as deref() and some basic functions for input and output. These functions are written in the implementation language (in our case, Unicon or Java), not the Jzero language. Here is the deref() method in Unicon:

  method deref(reg, od)
    case reg of {
      Op.R_ABS: {
        if od < finstr then return data.word(od)
        else return code[od]
        }
   ...