Article by Ayman Alheraki on January 11 2026 10:37 AM
The creation of a new programming language is a rare pursuit — one that demands curiosity, discipline, and a deep understanding of both syntax and semantics. Yet, throughout the last five decades, programming languages have evolved primarily through adaptation, extension, and reinterpretation of foundational designs — and few have been as enduring as the C family of languages.
C introduced a compact, low-level language model that influenced not only system software but also the conceptual structure of countless modern languages — from Java and JavaScript to C++, C#, Go, and even Rust. What made C—and later, C++—so successful is not just performance or proximity to hardware, but its clean, minimal syntax and expressive control over program structure.
This Series is born from a simple yet bold idea: to design and implement a new interpreted programming language using modern C++ — a language that honors the heritage of C-style syntax, while embracing the readability, modularity, and safety features expected in contemporary development. Unlike existing interpreters or domain-specific languages designed for niche areas, this project aspires to be general-purpose, educational, and production-aware.
It serves both as a hands-on implementation manual and as a case study in the architecture of real-world programming languages. The journey begins with tokenization and parsing, traverses deep into evaluation engines and function systems, and ascends toward embedding, debugging, and optimization — all constructed from scratch using C++20/23.
This Series is not just about theory. It is about engineering.
This Series is written for a particular kind of reader — the one who wants to go beyond using languages and instead understand how they work. If you are interested in how source code becomes behavior, how interpreters track scope and type, and how a runtime stack is built and maintained — then this Series is for you.
Experienced C++ developers wishing to broaden their design abilities into compilers and interpreters.
Educators seeking a clear, practical resource for teaching language implementation through C++.
Systems programmers designing DSLs or configuration languages for hardware, simulations, or compilers.
Language hackers and language design hobbyists who want to make their own scripting or experimental languages.
Compiler researchers and tooling developers exploring fast prototyping using modern C++ capabilities.
Solid command of C++ syntax and semantics, especially C++17 and newer.
Familiarity with programming language fundamentals: tokens, parsers, expressions, statements, and scoping.
Interest in the architecture of interpreters, not just front-end parsing but full language execution stacks.
Experience with modular software development, CMake, and optional familiarity with unit testing frameworks.
This Series is designed to be progressive and self-contained — each chapter builds on the last, with increasingly sophisticated structures, while remaining grounded in practical implementation. By the end, you will not only understand how languages are built — you will have built one.
The Series is divided into eight logically structured parts, followed by detailed appendices. Each part represents a clear phase in the construction of the language interpreter and runtime. Here’s what each part offers:
Sets up the base project using C++20/23 and CMake. Introduces the project layout, lexer/parser planning, and toolchain independence.
Implements a hand-written lexer and recursive-descent parser with C-style grammar and operator precedence. This forms the syntactic core of the language.
Handles blocks, declarations, conditional statements, loops, and expression-based statements. You begin seeing your language behave like C.
Implements the interpreter runtime: value representations, type system, variable scoping, function evaluation, and expression calculation.
Adds support for full function definitions, recursion, parameter passing, activation records, return values, and local scopes — the heart of C-style programming.
Introduces arrays, basic data structures, and standard library utilities (e.g., print, input, string functions), including file I/O and expression utility functions.
Presents error handling, debugging, REPL, stack traces, symbol resolution, command-line execution, and performance instrumentation.
Concludes with optional topics such as building a bytecode VM, optimizing interpreter performance, distribution, modular architecture, and embedding the language in other applications.
The Series culminates with full appendices covering language grammar in EBNF, CMake integration for language projects, testing strategies, benchmarks, and future work.
Every system in this Series is driven by clear and consistent design values:
Wherever feasible, components are designed with minimal abstraction. Instead of relying on parser generators or heavy macro systems, all systems — from token matching to AST evaluation — are written manually and explained in detail.
The language mirrors the behavior of C-like languages: block scoping with braces, strong yet flexible typing, well-defined operator precedence, and side-effect-bearing statements. It is not a toy — it mimics production-worthy language behavior.
Modern C++ is powerful and expressive. With std::variant, std::optional, ranges, concepts, lambdas, constexpr, smart pointers, and efficient containers, it provides the perfect toolkit for interpreter design while avoiding the pitfalls of earlier C++ versions.
Each component of the language — the lexer, parser, AST, evaluation, runtime environment, and standard library — is clearly separated. This ensures that you can refactor, test, and extend with confidence and modularity.
The goal is not just to write an interpreter but to build a foundation you can evolve — adding bytecode, building a compiler frontend, integrating with scripting tools, or repurposing components into embedded engines.
Each chapter concludes with a Milestone, ensuring you walk away not just with theory but a fully running feature. Hands-on coding, step-by-step diagnostics, and testable systems are embedded throughout the Series .
By the end of this Series, you will have accomplished what few developers ever do — created a working, extensible, modular, C-style interpreted language from scratch. You will be capable of:
Designing and implementing a syntax that is readable, minimal, and flexible.
Writing a full interpreter in C++ using variant-based evaluation and modern type safety.
Building function dispatch, return stacks, and expression evaluation systems that reflect real-world compiler internals.
Creating an extensible REPL and file execution engine.
Embedding your language into larger systems.
Measuring and optimizing interpreter performance.
Packaging your language for use across platforms.
Planning for future features such as object systems, foreign function interfaces, or bytecode JIT support.
The appendices serve as technical guides and reference implementations for everything you build, ensuring your language remains usable and relevant beyond the Series .
This is more than just a technical Series . It is a blueprint for ownership over your computing tools — a return to systems understanding in a world increasingly dependent on abstraction.
Whether your goal is academic, professional, or personal, I invite you to make this Series your companion in mastering the art of language design. You will not only write code — you will define what code means.
Let’s begin.