Format Slices

Important

The design and implementation chapter is outdated

{=[?]} will serialize the length (LEB128 compressed) first, then the first element will be serialized in (recursively) tagged format. The rest of elements will be serialized untagged.

“Tagged” means that the data will be preceded by the string indices that indicate how to format the data.

Example:

#![allow(unused)]
fn main() {
extern crate defmt;
use defmt::Format;

#[derive(Format)]
struct X {
    y: Y,
}

#[derive(Format)]
struct Y {
    z: u8,
}

fn serialize() {
    let xs = [X { y: Y { z: 42 }}, X { y: Y { z: 24 }}];
    defmt::info!("{=[?]}", &xs[..]);
    // on-the-wire: [
    //     1,  // "{=[?]}"
    //     2,  // `leb(xs.len())`
    //     2,  // "X {{ y: {=?} }}"  / outer tag with format nesting through `=?`
    //     3,  // "Y {{ z: {=u8} }}" / inner tag
    //     42, // xs[0].y.z
    //     (no tags for the second element)
    //     24, // xs[1].y.z
    // ]
}
}