64-bit number encoding/decoding in msgpack does not work

[pingyuusa]

Due to the limitation of javascript the way numbers are store, 64 bit integers can not represented correctly.

msgpack decodes a 64 bit number as ordinary javascript numeric type which is incorrect and looses precision.

n = "18446464814936021036"
x = [ 0xcf, 0xff, 0xff, 0x02, 0x04, 0x00, 0x00, 0xd8, 0x2c ]
a = msgpack.unpack(x)
a == 1844646481493602000 // not equal to n

unittest for this is incorrect too.

Need an alternate way to encode/decode 64 bit numbers to/from msgpack format

[bin-y]

64-bit numbers should be mapped to BigInt

[bin-y]

ping @pgriess @godsflaw

[godsflaw]

Yeah, this should be solved with one of the BigInt packages. I'm very busy, but would be happy to take a PR.

[bin-y]

hi, I did write some code to implement this for my own use. But my implemention used BigInt type directly and ignored backward compatibility. Due to the compatibility issue, I think it won't be a good PR, but it could be a reference if you need. Here is my commit bin-y@bccf8a0