details

README.md

@@ -3,3 +3,43 @@
 This repository follows the book [Writing an Interpreter in Go](https://interpreterbook.com/) and implements the code in Rust.
 
 [![Writing an Interpreter in Go](html_cover.png)](https://interpreterbook.com/)
+
+## Run
+
+```bash
+cargo run
+```
+
+## Architecture
+
+The interpreter is built in three main stages:
+
+1. **Lexer** — tokenizes the input source code.
+2. **Pratt parser** — builds an AST from the tokens.
+3. **Evaluator** — walks the AST and executes the program.
+
+Additional tests are in `evaluator/tests.rs`.
+
+## Features
+
+- Integers, strings, booleans
+- Arrays and hashes with index access
+- `let` bindings, `return` statements, and `if/else` expressions
+- First-class functions and closures
+
+## Project structure
+
+| Module | Purpose |
+|--------|---------|
+| `lexer` | Tokenizes source input |
+| `parser` | Pratt parser that produces an AST |
+| `ast` | AST node definitions |
+| `object` | Runtime values and environment |
+| `evaluator` | Tree-walking evaluator |
+| `repl` | Interactive REPL |
+
+## Tests
+
+```bash
+cargo test
+```