Function cssparser_color::parse_components

pub fn parse_components<'i, 't, P, F1, F2, F3, R1, R2, R3>(
    color_parser: &P,
    input: &mut Parser<'i, 't>,
    f1: F1,
    f2: F2,
    f3: F3
) -> Result<(Option<R1>, Option<R2>, Option<R3>, Option<f32>), ParseError<'i, P::Error>>where
    P: ColorParser<'i>,
    F1: FnOnce(&P, &mut Parser<'i, 't>) -> Result<R1, ParseError<'i, P::Error>>,
    F2: FnOnce(&P, &mut Parser<'i, 't>) -> Result<R2, ParseError<'i, P::Error>>,
    F3: FnOnce(&P, &mut Parser<'i, 't>) -> Result<R3, ParseError<'i, P::Error>>,

Parse the color components and alpha with the modern [color-4] syntax.