All C lexers are greedy, i.e. they extend the current token as far as they can. So "0..9" is split as a token "0." (numeric literal) followed by token "." (oper

All C lexers are greedy, i.e. they extend the current token as far as they can. So "0..9" is split as a token "0." (numeric literal) followed by token "." (operator) followed by token "9" (numeric literal). To do what you suggest, the lexers would need a major redesign, not just a small change.