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

Converting intermediate code to Jzero bytecode

The Jzero intermediate code generator from Chapter 9, Intermediate Code Generation, traversed a tree and created a list of intermediate code as a synthesized attribute in each tree node, named icode. The intermediate code for the whole program is the icode attribute in the root node of the syntax tree. In this section, we will use this list to produce our output bytecode. To generate bytecode, the gencode() method in the j0 class calls a new method in this class, named bytecode(), and passes it the intermediate code in root.icode as its input. The Unicon gencode() method that invokes this functionality in j0.icn looks like this. The two highlighted lines at the end of the following code snippet are added for bytecode generation, verified by simple text output:

   method gencode(root)
      root.genfirst()
      root.genfollow()
     ...