help me to understand this method

Here's the description in the .h file

Code:

---

/* Construct a dictionary of words.  When you create it, you may request
** the dictionary keep the dictionary in sorted order (or not) for
** iteration **/
typedef enum { UNSORTED_ORDER, SORTED_ORDER } sorted_e;
Words* DictionaryConstruct (sorted_e sorted);

---

and more info in the .c file

Code:

---

Words* DictionaryConstruct (sorted_e sorted)
{
  /* TODO:  Don't use the the sorted_e ... should we ?  Right now
  ** we always keep everything sorted, but we can make things
  ** faster if we don't have to keep them sorted... */
  if (sorted==UNSORTED_ORDER) {
    /* ?? */
  }

  Words* dummy = (Words*) malloc(sizeof(Words));
  dummy->next = 0;
  dummy->word = 0;
  dummy->count = -1;  /* Value to show we are at dummy node */
  return dummy;
}

---

I don't quite understand what does the UNSORTED_ORDER and SORTED does here?? Say I have a file that is sorted and I call the function createDictionary on it then what does it do?

sorted order supposes that adding new word should be accomplished using search of the appropriate location where to put it to maintain dictionary sorted

sorted dictionary gives a possibility of the binary search (long insert, quick access)
unsorted dictionary adds words at the begining or at the end (what is more suitable) - so insert operation is quick, search could take longer

so the first dictionary I should have it is unsorted... and then the second dictionary to be checked if the data exists in the same dictionary or not should be a sorted list..