> Making the minus part of the literal can lead to parsing ambiguity. Not really. It's done in java. Usually, minus ("-") is parsed as a token and then unary m

> Making the minus part of the literal can lead to parsing ambiguity. Not really. It's done in java. Usually, minus ("-") is parsed as a token and then unary minus on integer literals are transformed to a negative integer literal. So, -2147483648 is read as MINUS INT_LITERAL and thus transformed into "-2147483648" as an INT_LITERAL, but -(2147483648) should be read as MINUS L_PAREN INT_LITERAL R_PAREN and should thus not be transformed.