src/doc/book/second-edition/src/ch13-00-functional-features.md

   1 # Functional Language features in Rust - Iterators and Closures
   2
   3 Rust's design has taken inspiration from a lot of previous work. One of Rust's
   4 influences is functional programming, where functions are values that can be
   5 used as arguments or return values to other functions, assigned to variables,
   6 and so forth. We're going to sidestep the issue of what, exactly, functional
   7 programming is or is not, and instead show off some features of Rust that
   8 are similar to features in many languages referred to as functional.
   9
  10 More specifically, we're going to cover:
  11
  12 * *Closures*, a function-like construct you can store in a variable.
  13 * *Iterators*, a way of processing series of elements.
  14 * How to use these features to improve upon the project from the last chapter.
  15 * The performance of these features. Spoiler alert: they're faster than you
  16   might think!
  17
  18 This is not a complete list of Rust's influence from the functional style:
  19 pattern matching, enums, and many other features are too. But mastering
  20 closures and iterators are an important part of writing idiomatic, fast Rust
  21 code.