Build Your Own Programming Language (affan shaikhsurab) (z-library.sk, 1lib.sk, z-lib.sk)

# Build Your Own Programming Language — Reading Guide ## 【One-Line Pitch】 A hands-on, step-by-step guide to designing and implementing your own interpreted programming language from scratch, perfect for curious developers who want to understand what happens under the hood of Python, JavaScript, or any other language they use daily. ## 【Book Arc】 - **Opening (~0%–10%)**: Foundations of language theory — what makes a language, comparing human vs. programming languages (vocabulary, grammar, semantics), and why abstraction drives programming language evolution from Assembly to Python. - **Early (~10%–23%)**: Core pipeline concepts — how interpreted languages run code through the three "guardians": Lexer (tokenization), Parser (syntax checking), and Interpreter (execution). Includes a gentle introduction to automata theory, finite automata, and context-free grammars. - **Early (~23%–32%)**: Language design philosophy — defining your language's goals, choosing static vs. dynamic typing, creating keywords, and establishing syntax rules before writing any code. - **Middle (~32%–52%)**: Implementation deep-dive — building the Lexer class with token types and position tracking, constructing parsers with expression handling and AST (Abstract Syntax Tree) building, and implementing the interpreter with modular visit functions. - **Middle (~52%–75%)**: Advanced language features — adding functions with parameters, implementing scoping with symbol table stacks, return statements, arrays, dictionaries, and comments to SimpliLang. - **Late (~75%–100%)**: Object-oriented extensions — implementing classes with creation syntax, assignment, and access patterns, completing the full language implementation journey. ## 【Key Takeaways】 - **Three guardians of interpretation** (Middle): Every interpreted language runs through Lexer → Parser → Interpreter; understanding this pipeline is the mental model for everything else in the book. (Early) - **Vocabulary, grammar, semantics** (Early): Programming languages have fixed vocabulary (unlike flexible human language), strict grammar (syntax), and explicit semantics — the computer never guesses what you meant. (Early) - **Abstraction drives accessibility** (Middle): From Assembly to Fortran to C to Python, each abstraction layer made programming accessible to more people — this philosophy should guide your own language design decisions. (Middle) - **Tokenization is the foundation** (Early): Breaking code into meaningful tokens (like `print`, `(`, `"Hello"`, `)`) is the first step; without proper tokenization, parsing and interpretation cannot work. (Middle) - **Parser checks grammar and meaning** (Middle): The parser doesn't just check syntax — it validates semantics (e.g., `5 = x` is syntactically valid but semantically wrong) and extracts the key action from the code. (Middle) - **AST is the bridge** (Early): Abstract Syntax Trees represent the structure of your code in a way that's easy to traverse and interpret; building trees with binary nodes and handling parentheses are core parser skills. (Middle) - **Modular interpreter design** (Middle): Instead of massive if-else chains, use a single visit function that dynamically dispatches to the right method — this keeps your interpreter maintainable as features grow. (Middle) - **Scoping requires symbol table stacks** (Middle): Implementing functions with parameters requires a stack of symbol tables to handle variable visibility correctly across nested scopes. (Middle) ## 【Reading Tips】 - **Skim the theory chapters** (~0%–23%): The automata theory and grammar sections are useful context but not essential for implementation — focus on the Lexer/Parser/Interpreter pipeline concept and move on. - **Deep-read the implementation chapters** (~32%–52%): The Lexer, Parser, and Interpreter chapters are the heart of the book — code along with these, don't just read them. - **Watch for the "why" behind design choices**: The author explains language philosophy (why static vs. dynamic typing, why certain keywords) — these decisions matter more than the specific syntax of SimpliLang. - **Treat SimpliLang as a template**: Don't memorize SimpliLang's syntax; understand the pattern of "add feature → update Lexer → update Parser → update Interpreter" so you can apply it to your own language. - **Expect incremental complexity**: Each feature (functions, parameters, scoping, return, arrays, dictionaries, classes) follows the same three-step pattern — once you see it once, the rest becomes predictable. ## 【Coverage Limits】 This guide covers the book's progression from language theory through full interpreter implementation including classes. The excerpts do not cover the final chapters in full detail (particularly the complete class implementation and any testing/debugging strategies), so those sections may benefit from direct reading. ##