Re: [Cppcms-users] JSON integer conversion(s)

[Artyom <art...@ya...>]

Hello,

Thanks for the good point you bring.

Actually not only integer number were not printed correctly, but floating point 
ones as well.
I fixed this that numbers are printed with maximal possible precision and this 
should solve problem
(I also added test case for such numbers)

So your example generates 1277880000 string and not 1.27788e+09

(changeset 1298, you can take if from SVN)



> 
> I have noticed that the conversion of C++ integer numbers to json  goes
> trough converting it to a double. This can get undesired behavior  for
> large numbers when it automatic adds exponents when outputting it  as
> json. 

Double is capable representing integer numbers correctly, so the problem is not 
in converting
them to double but rather in printing them.

> 
> I want to keep the integer representation. If I want  a double
> representation I will convert it myself explicitly.
> If possible  by adding the function "void value::number(long int x);"
> this issue can be  solved.
> 

This is not correct solution as neither JSON nor JavaScript have no integer or 
double type they
have number type. So introducing "integer" type would be incorrect solution as 
it extends JSON object
representation.

IEEE floating point number can handle integer values correctly (with correct 
rounding and precision)
so there no need to change internal representation.

Also if you need real UUIDs neither integer nor double (and not even 64 bit 
integer) would be good enough.
You should probably use string.


Thanks for the report,
  Regards,
    Artyom