range-syntax-for-a-sequence-of-values

Range syntax for a sequence of values

In Rust, a range is a way to represent a sequence of values between a start and end point. A range are defined using the syntax start..end, where start is the first value in the range, and end is the first value not in the range.

Here are some examples of Rust ranges:

let a = 0..10;  // range from 0 to 9 inclusive
let b = 1..=10; // range from 1 to 10 inclusive
let c = ..5;    // range from start to 5 exclusive
let d = 5..;    // range from 5 to infinity

Ranges can be used in many contexts in Rust, such as in for loops:

for i in 0..10 {
    println!("{}", i);
}

This will print the numbers from 0 to 9.

Ranges can also be used with various methods provided by the Iterator trait, such as map, filter, fold, and more:

let nums = (0..10)
    .filter(|x| x % 2 == 0)
    .map(|x| x * 2)
    .collect::<Vec<_>>();
// nums is now [0, 4, 8, 12, 16]

This creates a range from 0 to 9, filters out any odd numbers, doubles the remaining even numbers, and collects them into a vector.

Overall, Rust ranges are a flexible and convenient way to represent sequences of values, and they are widely used throughout the language.