Merge pull request #53 from stolenzc/main

Update chapter titles and numbering in the Rust Patterns

Author: atulkhare4096

rust-patterns-book/src/ch00-introduction.md

@@ -49,15 +49,16 @@ Each chapter is tagged with a difficulty level:
 | 5. Channels 🟢 | `mpsc`, crossbeam, `select!`, actors | 1–2 hours | Can implement a channel-based worker pool |
 | 6. Concurrency 🟡 | Threads, rayon, Mutex, RwLock, atomics | 2–3 hours | Can pick the right sync primitive for a scenario |
 | 7. Closures 🟢 | `Fn`/`FnMut`/`FnOnce`, combinators | 1–2 hours | Can write a higher-order function that accepts closures |
-| 8. Smart Pointers 🟡 | Box, Rc, Arc, RefCell, Cow, Pin | 2–3 hours | Can explain when to use each smart pointer |
+| 8. Functional vs. Imperative 🟡 | Combinators, iterator adapters, functional patterns | 2–3 hours | Can explain when functional style beats imperative |
+| 9. Smart Pointers 🟡 | Box, Rc, Arc, RefCell, Cow, Pin | 2–3 hours | Can explain when to use each smart pointer |
 | **Part III: Systems & Production** | | | |
-| 9. Error Handling 🟢 | thiserror, anyhow, `?` operator | 1–2 hours | Can design an error type hierarchy |
-| 10. Serialization 🟡 | serde, zero-copy, binary data | 2–3 hours | Can write a custom serde deserializer |
-| 11. Unsafe 🔴 | Superpowers, FFI, UB pitfalls, allocators | 2–3 hours | Can wrap unsafe code in a sound safe API |
-| 12. Macros 🟡 | `macro_rules!`, proc macros, `syn`/`quote` | 2–3 hours | Can write a declarative macro with `tt` munching |
-| 13. Testing 🟢 | Unit/integration/doc tests, proptest, criterion | 1–2 hours | Can set up property-based tests |
-| 14. API Design 🟡 | Module layout, ergonomic APIs, feature flags | 2–3 hours | Can apply the "parse, don't validate" pattern |
-| 15. Async 🔴 | Futures, Tokio, common pitfalls | 1–2 hours | Can identify async anti-patterns |
+| 10. Error Handling 🟢 | thiserror, anyhow, `?` operator | 1–2 hours | Can design an error type hierarchy |
+| 11. Serialization 🟡 | serde, zero-copy, binary data | 2–3 hours | Can write a custom serde deserializer |
+| 12. Unsafe 🔴 | Superpowers, FFI, UB pitfalls, allocators | 2–3 hours | Can wrap unsafe code in a sound safe API |
+| 13. Macros 🟡 | `macro_rules!`, proc macros, `syn`/`quote` | 2–3 hours | Can write a declarative macro with `tt` munching |
+| 14. Testing 🟢 | Unit/integration/doc tests, proptest, criterion | 1–2 hours | Can set up property-based tests |
+| 15. API Design 🟡 | Module layout, ergonomic APIs, feature flags | 2–3 hours | Can apply the "parse, don't validate" pattern |
+| 16. Async 🔴 | Futures, Tokio, common pitfalls | 1–2 hours | Can identify async anti-patterns |
 | **Appendices** | | | |
 | Reference Card | Quick-look trait bounds, lifetimes, patterns | As needed | — |
 | Capstone Project | Type-safe task scheduler | 4–6 hours | Submit a working implementation |
@@ -102,38 +103,41 @@ OS threads, scoped threads, rayon, Mutex/RwLock/Atomics, Condvar, OnceLock, lock
 **[7. Closures and Higher-Order Functions](ch07-closures-and-higher-order-functions.md)** 🟢
 `Fn`/`FnMut`/`FnOnce`, closures as parameters/return values, combinators, higher-order APIs.
 
-**[8. Smart Pointers and Interior Mutability](ch08-smart-pointers-and-interior-mutability.md)** 🟡
+**[8. Functional vs. Imperative: When Elegance Wins (and When It Doesn't)](ch08-functional-vs-imperative-when-elegance-wins.md)** 🟡
+Combinators, iterator adapters, functional patterns.
+
+**[9. Smart Pointers and Interior Mutability](ch09-smart-pointers-and-interior-mutability.md)** 🟡
 Box, Rc, Arc, Weak, Cell/RefCell, Cow, Pin, ManuallyDrop.
 
 ### Part III: Systems & Production
 
-**[9. Error Handling Patterns](ch09-error-handling-patterns.md)** 🟢
+**[10. Error Handling Patterns](ch10-error-handling-patterns.md)** 🟢
 thiserror vs anyhow, `#[from]`, `.context()`, `?` operator, panics.
 
-**[10. Serialization, Zero-Copy, and Binary Data](ch10-serialization-zero-copy-and-binary-data.md)** 🟡
+**[11. Serialization, Zero-Copy, and Binary Data](ch11-serialization-zero-copy-and-binary-data.md)** 🟡
 serde fundamentals, enum representations, zero-copy deserialization, `repr(C)`, `bytes::Bytes`.
 
-**[11. Unsafe Rust — Controlled Danger](ch11-unsafe-rust-controlled-danger.md)** 🔴
+**[12. Unsafe Rust — Controlled Danger](ch12-unsafe-rust-controlled-danger.md)** 🔴
 Five superpowers, sound abstractions, FFI, UB pitfalls, arena/slab allocators.
 
-**[12. Macros — Code That Writes Code](ch12-macros-code-that-writes-code.md)** 🟡
+**[13. Macros — Code That Writes Code](ch13-macros-code-that-writes-code.md)** 🟡
 `macro_rules!`, when (not) to use macros, proc macros, derive macros, `syn`/`quote`.
 
-**[13. Testing and Benchmarking Patterns](ch13-testing-and-benchmarking-patterns.md)** 🟢
+**[14. Testing and Benchmarking Patterns](ch14-testing-and-benchmarking-patterns.md)** 🟢
 Unit/integration/doc tests, proptest, criterion, mocking strategies.
 
-**[14. Crate Architecture and API Design](ch14-crate-architecture-and-api-design.md)** 🟡
+**[15. Crate Architecture and API Design](ch15-crate-architecture-and-api-design.md)** 🟡
 Module layout, API design checklist, ergonomic parameters, feature flags, workspaces.
 
-**[15. Async/Await Essentials](ch15-asyncawait-essentials.md)** 🔴
+**[16. Async/Await Essentials](ch16-asyncawait-essentials.md)** 🔴
 Futures, Tokio quick-start, common pitfalls. (For deep async coverage, see our Async Rust Training.)
 
 ### Appendices
 
-**[Summary and Reference Card](ch17-summary-and-reference-card.md)**
+**[Summary and Reference Card](ch18-summary-and-reference-card.md)**
 Pattern decision guide, trait bounds cheat sheet, lifetime elision rules, further reading.
 
-**[Capstone Project: Type-Safe Task Scheduler](ch18-capstone-project.md)**
+**[Capstone Project: Type-Safe Task Scheduler](ch19-capstone-project.md)**
 Integrate generics, traits, typestate, channels, error handling, and testing into a complete system.
 
 ***

rust-patterns-book/src/ch08-functional-vs-imperative-when-elegance-wins.md

@@ -1,4 +1,4 @@
-# Chapter 8 — Functional vs. Imperative: When Elegance Wins (and When It Doesn't)
+# 8. Functional vs. Imperative: When Elegance Wins (and When It Doesn't)
 
 > **Difficulty:** 🟡 Intermediate | **Time:** 2–3 hours | **Prerequisites:** [Ch 7 — Closures](ch07-closures-and-higher-order-functions.md)
 

rust-patterns-book/src/ch09-smart-pointers-and-interior-mutability.md

@@ -1,4 +1,4 @@
-# 8. Smart Pointers and Interior Mutability 🟡
+# 9. Smart Pointers and Interior Mutability 🟡
 
 > **What you'll learn:**
 > - Box, Rc, Arc for heap allocation and shared ownership

rust-patterns-book/src/ch10-error-handling-patterns.md

@@ -1,4 +1,4 @@
-# 9. Error Handling Patterns 🟢
+# 10. Error Handling Patterns 🟢
 
 > **What you'll learn:**
 > - When to use `thiserror` (libraries) vs `anyhow` (applications)

rust-patterns-book/src/ch11-serialization-zero-copy-and-binary-data.md

@@ -1,4 +1,4 @@
-# 10. Serialization, Zero-Copy, and Binary Data 🟡
+# 11. Serialization, Zero-Copy, and Binary Data 🟡
 
 > **What you'll learn:**
 > - serde fundamentals: derive macros, attributes, and enum representations

rust-patterns-book/src/ch12-unsafe-rust-controlled-danger.md

@@ -1,4 +1,4 @@
-# 11. Unsafe Rust — Controlled Danger 🔴
+# 12. Unsafe Rust — Controlled Danger 🔴
 
 > **What you'll learn:**
 > - The five unsafe superpowers and when each is needed

rust-patterns-book/src/ch13-macros-code-that-writes-code.md

@@ -1,4 +1,4 @@
-# 12. Macros — Code That Writes Code 🟡
+# 13. Macros — Code That Writes Code 🟡
 
 > **What you'll learn:**
 > - Declarative macros (`macro_rules!`) with pattern matching and repetition

rust-patterns-book/src/ch14-testing-and-benchmarking-patterns.md

@@ -1,4 +1,4 @@
-# 13. Testing and Benchmarking Patterns 🟢
+# 14. Testing and Benchmarking Patterns 🟢
 
 > **What you'll learn:**
 > - Rust's three test tiers: unit, integration, and doc tests

rust-patterns-book/src/ch15-crate-architecture-and-api-design.md

@@ -1,4 +1,4 @@
-# 14. Crate Architecture and API Design 🟡
+# 15. Crate Architecture and API Design 🟡
 
 > **What you'll learn:**
 > - Module layout conventions and re-export strategies

rust-patterns-book/src/ch16-asyncawait-essentials.md

@@ -1,4 +1,4 @@
-# 15. Async/Await Essentials 🔴
+# 16. Async/Await Essentials 🔴
 
 > **What you'll learn:**
 > - How Rust's `Future` trait differs from Go's goroutines and Python's asyncio