pub fn alt_3<I: Clone, O, E, F, X1, X2>( parser_1: impl FnMut(I) -> NomRes<I, O, X1, F>, parser_2: impl FnMut(I) -> NomRes<I, O, X2, F>, parser: impl FnMut(I) -> NomRes<I, O, E, F>) -> impl FnMut(I) -> NomRes<I, O, E, F>