Gtk.TextIter.prototype.compare

function compare(rhs:Gtk.TextIter):Number {
    // Gjs wrapper for gtk_text_iter_compare()
}

A qsort()-style function that returns negative if lhs is less than rhs, positive if lhs is greater than rhs, and 0 if they're equal. Ordering is in character offset order, i.e. the first character in the buffer is less than the second character in the buffer.