Large numbers lose precision when decoding

A web service I need to use is returning the following in its JSON: "Id":1618065507111835497

But when using this Lua library to decode it, the result is losing precision as "Id" is returned as: 1.6080655071118e+18

In this case I can't change what the webservice is providing. I'm quite happy referring the data as a string - it's just an id value. I am limited to only using Lua 5.1.4.

Any help appreciated (e.g. pass back numbers that can't be correctly converted as strings?).

Thanks, Rob

But when using this Lua library to decode it, the result is losing precision as "Id" is returned as:

Decoding looks ok to me:

Lua 5.3.3  Copyright (C) 1994-2016 Lua.org, PUC-Rio
> json = require 'json'
> d = json.decode('{"id":1618065507111835497}')
> print(d.id)
1618065507111835497

But encoding does lose the precision:

> json.encode({id=1618065507111835497})
{"id":1.6180655071118e+18}

I think the problem is that Lua 5.1.4 does not include 64 bit integers, this was added in Lua 5.3. When I try and perform the same decode example on Lua 5.1.4 I lose precision. I'm restricted to using Lua 5.1.4 as it is embedded in the host application.

Lua 5.1.4  Copyright (C) 1994-2008 Lua.org, PUC-Rio
> json = require 'json'
> d = json.decode('{"id":1618065507111835497}')
> print(d.id)
1.6180655071118e+018