Function accessorFields

docs/app/js/sanddance-app.js:106509–106511

(fn)

    return fn == null ? null : fn.fname;
}
function accessorFields(fn) {
    return fn == null ? null : fn.fields;
}
function getter(path) {
    return path.length === 1 ? get1(path[0]) : getN(path);
}