SEXP nanoarrow_c_convert_array()

in r/src/convert_array.c [177:232]

• 47 lines of code
• 20 McCabe index (conditional complexity)

SEXP nanoarrow_c_convert_array(SEXP array_xptr, SEXP ptype_sexp) {
  // See if we can skip any ptype resolution at all
  if (ptype_sexp == R_NilValue) {
    enum VectorType vector_type = nanoarrow_infer_vector_type_array(array_xptr);
    switch (vector_type) {
      case VECTOR_TYPE_LGL:
      case VECTOR_TYPE_INT:
      case VECTOR_TYPE_DBL:
        return convert_array_default(array_xptr, vector_type, R_NilValue);
      case VECTOR_TYPE_CHR:
        return convert_array_chr(array_xptr);
      case VECTOR_TYPE_DATA_FRAME:
        return convert_array_data_frame(array_xptr, R_NilValue);
      default:
        break;
    }

    // Otherwise, resolve the ptype and use it (this will also error
    // for ptypes that can't be resolved)
    ptype_sexp = PROTECT(nanoarrow_c_infer_ptype(array_xptr_get_schema(array_xptr)));
    SEXP result = nanoarrow_c_convert_array(array_xptr, ptype_sexp);
    UNPROTECT(1);
    return result;
  }

  // Handle some S3 objects internally to avoid S3 dispatch
  // (e.g., when looping over a data frame with a lot of columns)
  if (Rf_isObject(ptype_sexp)) {
    if (nanoarrow_ptype_is_data_frame(ptype_sexp)) {
      return convert_array_data_frame(array_xptr, ptype_sexp);
    } else if (Rf_inherits(ptype_sexp, "vctrs_unspecified") ||
               Rf_inherits(ptype_sexp, "blob") ||
               Rf_inherits(ptype_sexp, "vctrs_list_of") ||
               Rf_inherits(ptype_sexp, "Date") || Rf_inherits(ptype_sexp, "hms") ||
               Rf_inherits(ptype_sexp, "POSIXct") ||
               Rf_inherits(ptype_sexp, "difftime")) {
      return convert_array_default(array_xptr, VECTOR_TYPE_OTHER, ptype_sexp);
    } else {
      return call_convert_array(array_xptr, ptype_sexp);
    }
  }

  // If we're here, these are non-S3 objects
  switch (TYPEOF(ptype_sexp)) {
    case LGLSXP:
      return convert_array_default(array_xptr, VECTOR_TYPE_LGL, ptype_sexp);
    case INTSXP:
      return convert_array_default(array_xptr, VECTOR_TYPE_INT, ptype_sexp);
    case REALSXP:
      return convert_array_default(array_xptr, VECTOR_TYPE_DBL, ptype_sexp);
    case STRSXP:
      return convert_array_chr(array_xptr);
    default:
      return call_convert_array(array_xptr, ptype_sexp);
  }
}