Vec<Vec<u8>> -> Vec<u8> , join/connect

help
1

I know about join and connec.

However, suppose we have:

let x: Vec<Vec<u8>> = ...;

is there anyway to construct a y: Vec<u8> that joins/connects all the lines of x via inserting \n after each line?

2 
let joined: Vec<u8> = x.iter()
    .flat_map(|v| v.iter().cloned().chain(std::iter::once('\n' as u8)))
    .collect();

Playground

In case this looks unfamiliar to you, here it is with detailed comments:

let joined: Vec<u8> =
    x.iter() // Iterator<&Vec<u8>>
        .flat_map(|v: &Vec<u8>| {
            v.iter()      // Iterator<&u8>
                .cloned() // -> Iterator<u8>
                .chain(std::iter::once('\n' as u8)) // -> Iterator<u8> ending with with '\n'
        })
        // `flat_map` above produces an Iterator<u8>.
        // In comparison, `map` would have produced a Iterator<Iterator<u8>>.
        // So you can think of `flat_map` as kinda "flattening" otherwise
        // nested iterators.
        .collect(); // -> Vec<u8>
3

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