begin <= end (15 <= 6) when slicing

[webxxxxx]

fn highlight(snippet: Snippet) -> String {
let mut result = String::new();
let mut start_from = 0;

for fragment_range in snippet.highlighted() {
    result.push_str(&snippet.fragment()[**start_from..fragment_range.start]**);
    result.push_str("<font color='red'>");
    result.push_str(&snippet.fragment()[fragment_range.clone()]);
    result.push_str("</font>");
    start_from = fragment_range.end;
}

result.push_str(&snippet.fragment()[start_from..]);
result

}