CCC-Iterator

使用C實作了Iterator
C語言實在是一個非常有趣的語言
應該說是
high level assembly ? 雖然我不太懂組合語言
但光是使用C就能感覺到他的power

#include 
#define TRUE 1
#define FALSE 0

struct Iterator;
struct List;
struct List_Node;
typedef unsigned short (*Method_hasNext)(struct Iterator*);
typedef void* (*Method_next)(struct Iterator*);


typedef struct Iterator {
 struct List_Node* current_element;
 Method_hasNext hasNext;
 Method_next next;
} Iterator;

typedef struct List_Node {
 void* data;
 struct List_Node* next;
} List_Node;

typedef struct List {
 List_Node* head;
 Iterator* (*getIterator)(struct List*);
 void (*addData)(struct List*, void*);
} List;

void addData(struct List* stru, void* data)
{
 List_Node* n;
 for(n = stru->head; n != NULL; n = n->next ) {
  if( (n->next) == NULL ) {
   n->data = data;
   break;
  }
 }
 n->next = (List_Node*) malloc(sizeof(List_Node));
 n->next->data = 0;
 n->next->next = 0;
}

unsigned short hasNext(Iterator* i)
{
 if(i->current_element->data == NULL)
  return FALSE;
 return TRUE;
}

void* next(Iterator* i)
{
 void* ret = i->current_element->data;
 i->current_element = i->current_element->next;
 return ret;
}

Iterator* getIterator(struct List* stru)
{
 Iterator* ret = (Iterator*) malloc(sizeof(Iterator));
 ret->current_element = stru->head;
 ret->hasNext = hasNext;
 ret->next = next;
 return ret;
}

List* New_List()
{
 List* ret = (List*) malloc(sizeof(List));
 ret->head = (List_Node*) malloc(sizeof(List_Node));
 ret->head->data = 0;
 ret->head->next = 0;
 ret->addData = addData;
 ret->getIterator = getIterator;
 return ret;
};

int main(void)
{
 List* strs = New_List();
 strs->addData(strs, "John\n");
 strs->addData(strs, "Paul\n");
 strs->addData(strs, "Ringo\n");
 strs->addData(strs, "George\n");
 Iterator* i;
 for( i = strs->getIterator(strs); i->hasNext(i) == TRUE;) {
  printf("%s", (char*)i->next(i));
 }
 return 0;
}