Textbook in PDF format Designing a custom programming language can be the most effective way to solve certain types of problems—especially when precision, safety, or domain-specific expressiveness matters. This book guides you through the full process of designing and implementing your own programming language and interpreter, from language design to execution, using modern C++. You’ll start by exploring when and why building a domain-specific language is worth it, and how to design one to fit a specific problem domain. Along the way, you’ll examine real-world interpreter architectures and see how their design decisions affect language behavior, capabilities, and runtime trade-offs. The book then walks through the entire process of interpreter implementation: defining syntax, building a lexer and parser, designing an abstract syntax tree, generating executable instructions, and implementing a runtime. All examples are in modern C++, with a focus on clean architecture and real-world usability. By the end, you’ll have a fully working interpreter for a domain-specific language designed to handle network protocols—plus the knowledge and tools to design your own programming language from scratch