Support to convert int json to value

[rohitjangid]

Hi

I was creating a native function which returns an int64 value and faced following error:

RUNTIME ERROR: Not a json type: 1234567890

After debugging this further, I found that we do not support converting int64 json to value (https://github.com/google/go-jsonnet/blob/master/interpreter.go#L934). Is there any reason we are not supporting int and int64 values? If not, I am happy to implement it.

[sparkprime]

Typically JSON does not support large integers - it supports doubles so it can go to a certain size of integer while keeping integer precision. That size is usually enough for everyone. In the Google Cloud APIs this is worked around by using a string to represent large numbers.

[sbarzowski]

You can encode it as float64. This is lossless for numbers up to 2^53-1. We don't support larger numbers – we simplify things by having only one number type and as Dave mentioned you cannot count on all JSON parsers handling bigger integers precisely anyway.