# The Dovetail Programming Language Source: https://dovetaillang.org/book/ ## Table of Contents --- ### [Part 1: Getting Started](https://dovetaillang.org/book/getting-started.md) - 1.1 Introduction to Dovetail - What is Dovetail? - Why another language? - Design philosophy and principles - Target platform (WasmGC) - Comparison with other languages - 1.2 Installation and Setup - Prerequisites (Rust toolchain, cargo) - Installing with Cargo - Installing from source - Verifying the installation - 1.3 Editor Setup - VS Code Extension - Extension features (syntax highlighting, LSP support) - Configuration options - 1.4 Your First Dovetail Program - Creating a project with `dovetail init` - The `Dovetail.toml` manifest file - Project directory structure - Writing "Hello, World!" - Building and running --- ### [Part 2: Dovetail Tool Commands](https://dovetaillang.org/book/tool-commands.md) - 2.1 The Dovetail CLI - 2.2 Project Structure - 2.3 Dependency Management - 2.4 CI and Local Compiler Development --- ### [Part 3: Language Basics](https://dovetaillang.org/book/language-basics.md) - 3.1 Layout-Sensitive Syntax - 3.2 Comments and Documentation - 3.3 Variables and Bindings - 3.4 Primitive Types - 3.5 Operators - 3.6 String Interpolation --- ### [Part 4: Control Flow](https://dovetaillang.org/book/control-flow.md) - 4.1 If Expressions - 4.2 Match Expressions - 4.3 Loops --- ### [Part 5: Functions](https://dovetaillang.org/book/functions.md) - 5.1 Function Definitions - 5.2 Positional Arguments and Configuration - 5.3 Closures and Lambdas - 5.4 First-Class Function References - 5.5 Method References - 5.6 Higher-Order Functions --- ### [Part 6: Type System](https://dovetaillang.org/book/type-system.md) - 6.1 Type Inference - 6.2 Records - Private construction and `with` updates - 6.3 Enums (Discriminated Unions) - Option Type - Result Type - Private construction with public pattern matching - 6.4 Tuples - 6.5 Newtypes - Private construction and inspection - 6.6 Type Aliases - 6.7 Lists, Arrays, and Slices - Lists and List Literals - Accessing and Matching Lists - Transforming and Iterating Lists - Choosing Between Array and List - Shared Array Views and Slicing Syntax - Slice Bounds and Constructors - Copying, Comparing, and Iterating - Slices and Strings - 6.8 Modules - 6.9 Extension Methods - 6.10 The Any Type and Type Casting - The Any Type - Type Testing with `is` - Type Casting with `as` - Working with Generic Types and Arrays - 6.11 Interfaces and Interface Types - Declaring and Implementing Interfaces - Generic Interfaces and Bounds - Intersections and Upcasts - Inheritance, Defaults, and `Self` - Interface Restrictions and `Any` - Choosing a Contract --- ### [Part 7: Generics](https://dovetaillang.org/book/generics.md) - 7.1 Generic Functions - 7.2 Generic Types - 7.3 Constraints --- ### [Part 8: Traits and Implementations](https://dovetaillang.org/book/traits.md) - 8.1 Defining Traits - 8.2 Implementing Traits - Implementations and private types - 8.3 Core Traits - Identity Equality and Hashing - 8.4 The Orphan Rule - 8.5 Trait and Interface Inheritance - 8.6 Default Methods and Properties - 8.7 Method Resolution and Explicit Disambiguation --- ### [Part 9: Classes and Object-Oriented Programming](https://dovetaillang.org/book/classes.md) - 9.1 Class Definitions - 9.2 Methods - 9.3 Class Body Fields - 9.4 Private Constructors - 9.5 Mutable Fields - 9.6 Inheritance - 9.7 Abstract Classes - 9.8 Sealed Abstract Classes - 9.9 Generic Classes - 9.10 Implementing Traits for Classes - 9.11 Extension Properties - 9.12 Extension Methods for Classes - 9.13 Visibility Modifiers - 9.14 Classes vs Records - 9.15 Class Identity --- ### [Part 10: Error Handling](https://dovetaillang.org/book/error-handling.md) - 10.1 No Exceptions - 10.2 Option Type - 10.3 Result Type - 10.4 Railway-Oriented Programming - 10.5 Panics and Assertions --- ### [Part 11: Packages and Modules](https://dovetaillang.org/book/packages.md) - 11.1 Package Declaration - 11.2 Imports - 11.3 Visibility - Type visibility and private construction - 11.4 No Circular Dependencies - 11.5 GitHub Dependencies --- ### [Part 12: Async Programming](https://dovetaillang.org/book/async.md) - 12.1 The Async Type - 12.2 Async Functions - 12.3 The `await` Operator - 12.4 Running Async Code - 12.5 Parallel Execution --- ### [Part 13: Resource Management](https://dovetaillang.org/book/resources.md) - 13.1 The `use` Keyword - 13.2 LIFO Release Order - 13.3 Release on Failure - 13.4 Composing Resources - 13.5 Error Conversion at the Use Site --- ### [Part 14: Streams](https://dovetaillang.org/book/streams.md) - 14.1 Descriptions and Consumption - 14.2 Creating a Source - 14.3 Chunks and Transformations - 14.4 Concatenation and Flat Mapping - 14.5 Repeating Effects and Time - 14.6 Errors and Resource Lifetimes - 14.7 Merging Concurrent Sources - 14.8 Running and Folding - 14.9 Byte Transports --- ### [Part 15: Testing](https://dovetaillang.org/book/testing.md) - 15.1 Unit Tests - 15.2 Test Organization - 15.3 Test Attributes - 15.4 Running Tests - 15.5 Testing Best Practices --- ### [Part 16: Macros](https://dovetaillang.org/book/macros.md) - 16.1 Overview - 16.2 The `@derive` Attribute - Derives and private types - 16.3 Built-in Derives - 16.4 Writing Custom Derives (Rhai) --- ### [Part 17: Components](https://dovetaillang.org/book/components.md) - 17.1 Declaring a Component Dependency - 17.2 What Gets Generated - 17.3 Using SQLite - 17.4 Building and Running - 17.5 Limits (v1) --- ### [Part 18: Project Structure and Onion Architecture](https://dovetaillang.org/book/project-structure.md) - 18.1 The Dependency Rule - 18.2 Three Projects per Bounded Context - `primitives` — the value vocabulary - `contract` — the public wire surface (data and service contracts) - `app` — the context itself - 18.3 Three Packages Inside `app` - The domain package - The application package - The infrastructure package - 18.4 What the Compiler Enforces - 18.5 Variant: the Domain Layer as Its Own Project - 18.6 Ports and Adapters - Repositories - The anti-corruption layer - 18.7 The Composition Root - 18.8 The Shared Kernel - 18.9 Talking to Other Bounded Contexts - Service contracts, client stubs, and the ACL - Integration events - 18.10 Testing the Layers - 18.11 Rules at a Glance --- ### [Part 19: The Domain Layer](https://dovetaillang.org/book/ddd.md) - 19.1 Start With the Types - 19.2 Make Illegal States Unrepresentable - Rules of thumb - Errors are types too - The compiler as reviewer - How far to take it - 19.3 Value Objects - 19.4 Entities - Make the transition boundary enforceable - 19.5 Two Styles: Values or Objects - 19.6 Aggregates - 19.7 Domain Events - 19.8 Domain Services - Pass the fact, not the port - 19.9 Factories and Reconstitution - 19.10 The Anemic Domain Model - 19.11 Testing the Domain - 19.12 A Change, End to End --- ### [Part 20: The Application Layer](https://dovetaillang.org/book/application-layer.md) *(outline)* - 20.1 What a Use Case Owns - The "one change, one transaction, one aggregate" rules - Consequences: notification or obligation - The sandwich: IO at the edges - When the sandwich does not fit: the layered cake - 20.2 Commands, Queries, and Results - Errors from the domain - 20.3 The Three Triggers - Requests - Event handlers - Jobs - 20.4 Repositories - 20.5 Publishing Integration Events - 20.6 Sagas, Compensation, and Durable Execution - Two shapes: backward and forward recovery - The problem durable execution solves - Dovetail has no durable execution runtime today - 20.7 Cross-Cutting Concerns - 20.8 Testing the Application Layer - 20.9 Worked Example --- ### [Part 21: Strategic Design and Context Mapping](https://dovetaillang.org/book/context-mapping.md) *(outline)* - 21.1 Subdomains: Core, Supporting, Generic - 21.2 Ubiquitous Language and Bounded Contexts - 21.3 Context Relationship Patterns - 21.4 Direct Contract Use vs Anticorruption Layer - 21.5 Integration Events - 21.6 Drawing and Maintaining the Context Map - 21.7 Splitting and Merging Contexts --- ### [Part 22: Standard Library Overview](https://dovetaillang.org/book/stdlib.md) - 22.1 Core Types - 22.2 Collections - 22.3 Text Processing - 22.4 Math - 22.5 I/O - 22.6 Networking - 22.7 Time - 22.8 JSON - 22.9 Randomness and Crypto - 22.10 Streams and SQLite --- ### [Part 23: Best Practices](https://dovetaillang.org/book/best-practices.md) - 23.1 Code Style - 23.2 Functional Patterns - 23.3 Error Handling Patterns - 23.4 Project Organization --- ### [Part 24: Prefixed String Literals](https://dovetaillang.org/book/prefixed-literals.md) - 24.1 Why not just build a string? - 24.2 Syntax - 24.3 What a literal lowers to - 24.4 Bounds come from the builder, not the compiler - 24.5 Writing a builder - 24.6 Declaring a prefix - 24.7 Composition instead of in-string control flow --- ### [Part 25: Tuple Extension (Advanced)](https://dovetaillang.org/book/tuple-extension.md) - 25.1 Extending a Tuple - 25.2 Extension in Generic Types - 25.3 Tuple Shape and Accessors - 25.4 Pair and Recursive Implementations - 25.5 Parser Composition - 25.6 Enclosing Parameter Bounds --- ### [Part 26: Advanced Generics](https://dovetaillang.org/book/advanced-generics.md) - 26.1 Generic Extensions - 26.2 Class Constraints - 26.3 Bounds on Enclosing Parameters - 26.4 Trait and Override Contracts - 26.5 Variance and Method Bounds - Plain Parameters, `out`, and `in` - Conditional Bounds on Virtual Methods - 26.6 Pattern Matching on Generic Types - 26.7 Generic Trait Defaults - 26.8 Associated Outputs - 26.9 Generic Associated Types - Generic Resource Helpers - 26.10 Inherited Overloads --- ### [Part 27: Production Deployment and CI](https://dovetaillang.org/book/production-deployment.md) - 27.1 Prepare a Reproducible Release - 27.2 Image Permissions and Deployment Configuration - 27.3 Configure CI Checks - 27.4 Build and Publish in CI - 27.5 Run and Verify the Image - 27.6 Operate and Roll Back --- ### Appendix - [A. Grammar Reference](https://dovetaillang.org/reference/grammar.md) - [B. Operator Precedence Table](https://dovetaillang.org/reference/grammar.md#operator-precedence-table) - [C. Reserved Keywords](https://dovetaillang.org/reference/grammar.md#keywords) - [D. Standard Library Quick Reference](https://dovetaillang.org/book/stdlib.md) [How this book is validated](https://dovetaillang.org/guides/book-validation.md)