Identify en email address under the cursor using rangy

gistfile1.js

// Still a work in progress
// NOTE: Requires Rangy 1.3alpha to use the word options with expand
// NOTE: Must include the core and the text select libraries
// TODO: Update loop to use rangy node iterator
// TODO: Only return email addresses
function getEmailUnderCursor(elem, x, y) {
    if(elem.nodeType == elem.TEXT_NODE) {
        //var doc_range = elem.ownerDocument.createRange();

        var range = rangy.createRange();
        range.selectNodeContents(elem);
        //range.selectNodeContents(elem);
        var currentPos = 0;
        var endPos = range.endOffset;

        while(currentPos+1 < endPos) {
            range.setStart(elem, currentPos);
            range.setEnd(elem, currentPos+1);
            //console.log(range);
            var client_rect = range.nativeRange.getBoundingClientRect();
            if(client_rect.left <= x && client_rect.right >= x &&
                client_rect.top  <= y && client_rect.bottom >= y) {

                range.expand('word', {
                    wordOptions: {
                        wordRegex: /(([^<>()[\]\\.,;:\s@\"]+(\.[^<>()[\]\\.,;:\s@\"]+)*)|(\".+\"))@((\[[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\])|(([a-zA-Z\-0-9]+\.)+[a-zA-Z]{2,}))/gi
                    }
                });

                word = range.toString();

                range.detach();

                return word;
            }
            currentPos += 1;
        }
    } else {
        for(var i = 0; i < elem.childNodes.length; i++) {
            var range = rangy.createRange();
            range.selectNodeContents(elem.childNodes[i]);

            var client_rect = range.nativeRange.getBoundingClientRect();
            if(client_rect.left <= x && client_rect.right >= x &&
                client_rect.top  <= y && client_rect.bottom >= y) {
                range.detach();
                return(getEmailUnderCursor(elem.childNodes[i], x, y));
            } else {
                range.detach();
            }
        }
    }
    return(null);
}   

document.addEventListener("mousemove", function(e) {
    getEmailUnderCursor(e.target, e.x, e.y); 
});