Method edge_node

src/xpath_functions.rs:979–1017

Return the root of the ancestor tree if we are at the left/right side of a path from that to 'element'

(element: Element<'a>, use_left_side: bool, stop_node_name: &str)

impl EdgeNode {
    // Return the root of the ancestor tree if we are at the left/right side of a path from that to 'element'
    fn edge_node<'a>(element: Element<'a>, use_left_side: bool, stop_node_name: &str) -> Option<Element<'a>> {
        let element_name = name(&element);
        if element_name == "math" {
            return Some(element);
        };

        let parent = element.parent().unwrap().element().unwrap();   // there is always a "math" node
        let parent_name = name(&parent);

        // first check to see if we have the special case of punctuation as last child of math/mrow element
        // it only matters if we are looking at the right edge

        // debug!("EdgeNode: there are {} preceding siblings",element.preceding_siblings().len() );
        if use_left_side  && !element.preceding_siblings().is_empty() {// not at left side
            return None;
        };

        if !use_left_side && !element.following_siblings().is_empty() {  // not at right side
            // check for the special case that the parent is an mrow and the grandparent is <math> and we have punctuation
            let grandparent = parent.parent().unwrap().element().unwrap();
            if name(&grandparent) == "math" &&
               parent_name == "mrow" && parent.children().len() == 2 {      // right kind of mrow
                let text = get_text_from_element( as_element(parent.children()[1]) );
                if text == "," || text == "." || text == ";" || text == "?" {
                    return Some(grandparent);
                }
            }
             return None;
        };

        // at an edge -- check to see the parent is desired root
        if parent_name == stop_node_name || 
           (stop_node_name == "2D" && MATHML_2D_NODES.contains(name(&parent))) {
            return Some(parent);
        };
        
        // debug!("EdgeNode: recurse to {}", parent_name);
        return EdgeNode::edge_node(parent, use_left_side, stop_node_name)
    }
}

// EdgeNode(node, "left"/"right", stopNodeName)