1. 1. Introduction
  2. 2. Getting Started
  3. 3. Tutorial: Guessing Game
  4. 4. Syntax and Semantics
    1. 4.1. Variable Bindings
    2. 4.2. Functions
    3. 4.3. Primitive Types
    4. 4.4. Comments
    5. 4.5. if
    6. 4.6. Loops
    7. 4.7. Vectors
    8. 4.8. Ownership
    9. 4.9. References and Borrowing
    10. 4.10. Lifetimes
    11. 4.11. Mutability
    12. 4.12. Structs
    13. 4.13. Enums
    14. 4.14. Match
    15. 4.15. Patterns
    16. 4.16. Method Syntax
    17. 4.17. Strings
    18. 4.18. Generics
    19. 4.19. Traits
    20. 4.20. Drop
    21. 4.21. if let
    22. 4.22. Trait Objects
    23. 4.23. Closures
    24. 4.24. Universal Function Call Syntax
    25. 4.25. Crates and Modules
    26. 4.26. `const` and `static`
    27. 4.27. Attributes
    28. 4.28. `type` aliases
    29. 4.29. Casting between types
    30. 4.30. Associated Types
    31. 4.31. Unsized Types
    32. 4.32. Operators and Overloading
    33. 4.33. Deref coercions
    34. 4.34. Macros
    35. 4.35. Raw Pointers
    36. 4.36. `unsafe`
  5. 5. Effective Rust
    1. 5.1. The Stack and the Heap
    2. 5.2. Testing
    3. 5.3. Conditional Compilation
    4. 5.4. Documentation
    5. 5.5. Iterators
    6. 5.6. Concurrency
    7. 5.7. Error Handling
    8. 5.8. Choosing your Guarantees
    9. 5.9. FFI
    10. 5.10. Borrow and AsRef
    11. 5.11. Release Channels
    12. 5.12. Using Rust without the standard library
  6. 6. Nightly Rust
    1. 6.1. Compiler Plugins
    2. 6.2. Inline Assembly
    3. 6.3. No stdlib
    4. 6.4. Intrinsics
    5. 6.5. Lang items
    6. 6.6. Advanced linking
    7. 6.7. Benchmark Tests
    8. 6.8. Box Syntax and Patterns
    9. 6.9. Slice Patterns
    10. 6.10. Associated Constants
    11. 6.11. Custom Allocators
  7. 7. Glossary
  8. 8. Syntax Index
  9. 9. Bibliography

Glossary

Not every Rustacean has a background in systems programming, nor in computer science, so we've added explanations of terms that might be unfamiliar.

Abstract Syntax Tree

When a compiler is compiling your program, it does a number of different things. One of the things that it does is turn the text of your program into an ‘abstract syntax tree’, or ‘AST’. This tree is a representation of the structure of your program. For example, 2 + 3 can be turned into a tree:

  +
 / \
2   3

And 2 + (3 * 4) would look like this:

  +
 / \
2   *
   / \
  3   4

Arity

Arity refers to the number of arguments a function or operation takes.

let x = (2, 3);
let y = (4, 6);
let z = (8, 2, 6);Run

In the example above x and y have arity 2. z has arity 3.

Bounds

Bounds are constraints on a type or trait. For example, if a bound is placed on the argument a function takes, types passed to that function must abide by that constraint.

Combinators

Combinators are higher-order functions that apply only functions and earlier defined combinators to provide a result from its arguments. They can be used to manage control flow in a modular fashion.

DST (Dynamically Sized Type)

A type without a statically known size or alignment. (more info)

Expression

In computer programming, an expression is a combination of values, constants, variables, operators and functions that evaluate to a single value. For example, 2 + (3 * 4) is an expression that returns the value 14. It is worth noting that expressions can have side-effects. For example, a function included in an expression might perform actions other than simply returning a value.

Expression-Oriented Language

In early programming languages, expressions and statements were two separate syntactic categories: expressions had a value and statements did things. However, later languages blurred this distinction, allowing expressions to do things and statements to have a value. In an expression-oriented language, (nearly) every statement is an expression and therefore returns a value. Consequently, these expression statements can themselves form part of larger expressions.

Statement

In computer programming, a statement is the smallest standalone element of a programming language that commands a computer to perform an action.