Function parse_general 

pub(crate) fn parse_general<'a>(
    handler: Handler,
    source: &'a str,
    start_pos: u32,
    parse: impl FnOnce(&mut Lexer<'a>) -> Result<SyntaxNode<'a>, ParseError<usize, LalrToken<'a>, &'static str>>,
) -> Result<SyntaxNode<'a>>