r - R の精度で int64 を JSON シリアライズおよびデシリアライズする機能

Question

R では、Int64 整数を JSON との間で正確にシリアル化することはできません。これは、既存の JSON ライブラリが値を強制的に数値に変換するか、科学表記法で数値を表すことを期待するためです。

Int64 数値全体を正確に JSON との間で正確にシリアル化および逆シリアル化する方法を知っている人はいますか、またはライブラリの変更 (おそらく RJSONIO への) が必要ですか?

これまでに試したライブラリを含む完全なストーリーと、暫定的に必要なガッキーな回避策:

> library(gmp)
> library(bit64)
> library(rjson)
> library(RJSONIO)
> 
> options.bak <- getOption("digits")
> options(digits = 22)
> 
> #This is our value! 
> int64.text <- "5812766036735097952"
> #This whole number loses precision when stored as a numeric.
> as.bigz(int64.text) - as.numeric(int64.text)
Big Integer ('bigz') :
[1] 96
> 
> #PROBLEM 1: Deserialization from JSON
> 
> #rjson parses this number as a numeric, and demonstrates the same loss.
> json.text <- "{\"record.id\":5812766036735097952}"
> rjson.parsed <- rjson::fromJSON(json.text)$record.id
> str(rjson.parsed)
 num 5.81e+18
> as.bigz(int64.text) - as.bigz(rjson.parsed)
Big Integer ('bigz') :
[1] 96
> #so does RJSONIO, a library that allows you to specify floating point precision.
> rjsonio.parsed <- RJSONIO::fromJSON(json.text, digits = 50)["record.id"]
> as.bigz(int64.text) - as.bigz(rjsonio.parsed)
Big Integer ('bigz') :
[1] 96
> 
> #For now, I have solved this by hacking the JSON with some regex magic. Here's a snippet, although
> #   i'm really processing a much larger JSON string. 
> modified.json.text <- gsub("record.id\\\":([0-9]+)", "record.id\\\":\"\\1\"", json.text)
> id.text  <- fromJSON(modified.json.text)$record.id
Error in fromJSON(modified.json.text)$record.id : 
  $ operator is invalid for atomic vectors
> id.bigz <- as.bigz(int64.text)
> id.bigz - as.bigz(int64.text)
Big Integer ('bigz') :
[1] 0
> id.bigz
Big Integer ('bigz') :
[1] 5812766036735097952
> 
> #However, hacking the JSON isn't really a good solution, and relies upon there being convenient tags
> # nearby for the regex match to work. Being able to serialize to a precise data structure in the 
> # first place is best. Sorry R, there are largers number than 2^32
> 
> ###Problem 2: Deserialization 
> #Neither rjson and RJSONIO support bigz objects:
> rjson::toJSON(as.bigz(int64.text))
Error in rjson::toJSON(as.bigz(int64.text)) : 
  unable to convert R type 24 to JSON
> RJSONIO::toJSON(as.bigz(int64.text), digits = 50)
Error: evaluation nested too deeply: infinite recursion / options(expressions=)?
Error during wrapup: evaluation nested too deeply: infinite recursion / options(expressions=)?
> #Int64 will serialize, but with scientific notation:
> toJSON(as.integer64(int64.text))
[1] "[ 4.0156e+80 ]"
> RJSONIO::toJSON(as.integer64(int64.text, digits = 50))
[1] "[ 4.0156e+80 ]"
> 
> #So again, another JSON hack is in order:
> encoded.json.out <- toJSON(c(record.id = paste0("INT64", int64.text)))
> modified.json.out <- gsub("record.id\\\":\"INT64([0-9]+)\"", "record.id\\\":\\1", encoded.json.out)
> modified.json.out
[1] "{\n \"record.id\": \"INT645812766036735097952\" \n}"
> options(digits = options.bak)