var_create_internal

[Jason Stover]

Question:

/* Create a variable to be used for internal calculations only */
struct variable *
var_create_internal (int case_idx)
{
  struct variable *v = var_create ("$internal", 0);

  struct vardict_info vdi;

  vdi.dict = NULL;
  vdi.dict_index = 0;
  vdi.case_index = case_idx;

  var_set_vardict (v, &vdi);

  return v;
}

/* Dictionary data stored in variable. */
struct vardict_info
  {
    int dict_index;     /* Dictionary index containing the variable. */
    int case_index;     /* Index into case of variable data. */
    struct dictionary *dict;  /* The dictionary containing the variable */
  };

What is the "case of variable data"? All the examples I see in
src/language/stats show a value of either 0, 1 or 2.

-Jason