Option to read empty array to NULL or vector instead of list

[JosiahParry]

The details in the following JSON is parsed into a list() by yyjsonr {"error":{"code":400,"message":"Invalid URL","details":[]}}

I know that details will only every be a character vector. The list() is causing an issue with existing code that expects either a NULL or a character vector. Is there an option that can be set to change the behavior of yyjsonr in this case?

[coolbutuseless]

Thanks for raising this issue. There's a few things around NULL/empty handling that are on my list - I'll add this to it.

Notes on arbitrary R objects when JSON []-array is empty

• Inopts_read_json()

  • Add empty_array = ...
  • Value can be any R object.
  • By default: list(), but common alternatives would be NULL, "" (empty string), NA

• Empty json []-array handling is here:

  yyjsonr/src/R-yyjson-parse.c

  Line 1135 in 07655b5

  // Empty []-array becomes an empty list

Also need to think about json {}-objects

• Should the same be done for empty {}-objects?
• Currently: empty json {}-objects produce an empty named list() in R
• Empty {}-object handling could go about here:

  yyjsonr/src/R-yyjson-parse.c

  Line 1633 in 07655b5

  R_xlen_t n = (R_xlen_t)yyjson_get_len(obj);