Turn pinyin written with tone numbers and turn it into pinyin with node marks. prettify_pinyin accepts input in the CC-CEDICT pinyin format (space separated syllables with tone numbers at the end of each syllable), for example: "ni3 hao3" will get turned into "nǐ hǎo".
use prettify_pinyin::prettify;
let formatted: String = prettify("ma1 ma2 ma3 ma4 ma");
println!("{}", formatted); // --> mā má mǎ mà ma