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

Generating code for control flow

Generating code for control structures such as conditionals and loops is more challenging than code for arithmetic expressions, as shown in the preceding section. Instead of using synthesized attributes in a single bottom-up pass, code for control flow uses label information that must be moved to where it is needed using inherited attributes. This may involve multiple passes through the syntax tree. We will start with the condition expression logic needed for even the most basic control flow, such as if statements, and then show you how to apply that to loops, followed by considerations needed for method calls.

Generating label targets for condition expressions

We have already set up for control flow by assigning the first and follow attributes, as described in the Annotating syntax trees with labels for control flow section. Consider what role the first and follow attributes play, starting with the simplest control flow statement, the if statement...