// The tags that will be assossiated with a piece of text, that could be a rope.
struct Tag {
    PrintRed,
    Underline,
    Normal,
    Skip(usize)
}

use Tag::*;
impl any_rope::Measurable for Tag {
    fn width(&self) -> usize {
        match self {
            // The zero here represents the fact that multiple tags may be placed
            // in the same character.
            PrintRed | Underline | Normal => 0,
            // Skip here is an amount of characters with no tags in them.
            Skip(amount) => *amount
        }
    }
}

// An `&str` that will be colored.
let my_str = "This word will be red!";

// Here's what this means:
// - Skip 5 characters;
// - Change the color to red;
// - Skip 4 characters;
// - Change the rendering back to normal.
let mut tags = any_rope::Rope::from_slice(&[Skip(5), PrintRed, Skip(4), Normal]);
// Do note that Tag::Skip only represents characters because we are also iterating
// over a `Chars` iterator, and have chosen to do so.

// An empty range, when used in an inclusive removal will remove all
// 0 width elements in that specific width.
// `Rope::remove_exclusive()` would keep them.
// In this case, that would be `Tag::PrintRed`
tags.remove_inclusive(5..5);
// In place of that `Tag::PrintRed`, we will insert `Tag::Underline`.
tags.insert(5, Underline);

// The AnyRope iterator not only returns the element in question, but also the width
// where it starts.
let mut tags_iter = tags.iter().peekable();

for (cur_index, ch) in my_str.chars().enumerate() {
    // The while let loop here is a useful way to activate all tags within the same
    // character. For example, we could have a sequence of [Tag::UnderLine, Tag::PrintRed]
    // in the `Rope`, both of which have a width of 0, allowing one to execute multiple
    // `Tag`s in a single character.
    while let Some((index, tag)) = tags_iter.peek() {
        if *index == cur_index {
            activate_tag(tag);
            tags_iter.next();
        } else {
            break;
        }
    }
    print!("{}", ch);
}