Thanks for your analysis (and the Ruby and JS reports). The more I think about it the more I think parsers should not parse to numbers by default, but instead to (using a Haskell-based pseudo type):

  data Sign = Positive | Negative

  data Digit = Zero | One ... Eight | Nine

  data JSONNumber = JSONNumber
    { _sign           :: Maybe Sign
    , _integerPart    :: [Digit]
    , _fractionalPart :: Maybe [Digit]
    }

Actually this should include exponents as well -- basically parsers should just report exactly what the spec allows, without coercing to float or whatever.

Of course, users of the parsers could ask to have a number converted to a float, but that wouldn't be the default.

We're a long way from that though. At the moment I don't even feel like I can write a protocol that expected implementations to distinguish `1` and `1.0`. This should not be the case.