Function diff

pub fn diff<'a, 'doc1, 'doc2>(
    tree1: &'doc1 XTree<'doc1>,
    tree2: &'doc2 XTree<'doc2>,
) -> Vec<Edit<'a, 'doc1, 'doc2>>

Calculate the difference between two XML trees, represented by the minum edit operations to transform tree1 to tree2.