[MySQL] Add in a few interfaces for iteration. MySqlDataTable is its …

…own iterator, so implement that interface. MySqlDataRow uses a HashIterator over the column names hash. In the future we might use something more custom, since rows should be able to be iterated by column name and by raw indexed value

mysql/pmc/mysqldatarow.pmc

@@ -69,4 +69,16 @@ pmclass MySqlDataRow dynpmc auto_attrs provides array provides hash {
     {
         return VTABLE_elements(INTERP, PARROT_MYSQLDATAROW(SELF)->data);
     }
+
+    VTABLE PMC *get_iter()
+    {
+        return Parrot_pmc_new_init(INTERP, enum_class_HashIterator, SELF);
+    }
+
+    VTABLE void * get_pointer()
+    {
+        // Return a pointer to the Hash* representing the column hash. Currently
+        // we get that from the table. This interface is required by HashIterator.
+        return VTABLE_get_pointer_keyed(INTERP, PARROT_MYSQLDATAROW(SELF)->table, SELF);
+    }
 }

mysql/pmc/mysqldatatable.pmc

@@ -48,12 +48,6 @@ pmclass MySqlDataTable dynpmc auto_attrs provides iterator {
             Parrot_hash_mark(INTERP, colnames);
     }
 
-    VTABLE void* get_pointer()
-    {
-        MYSQL_RES * const result = GET_RESULT(SELF);
-        return result;
-    }
-
     VTABLE void destroy()
     {
         MYSQL_RES * const result = GET_RESULT(SELF);
@@ -103,4 +97,11 @@ pmclass MySqlDataTable dynpmc auto_attrs provides iterator {
         // This is necessary for the iterator interface
         UNUSED(iter_dir);
     }
+
+    VTABLE void *get_pointer_keyed(PMC *row)
+    {
+        // For iterating rows, we need an easy way to get a pointer to the colnames
+        // hash. In the future we should find a better way to do it.
+        return PARROT_MYSQLDATATABLE(SELF)->colnames;
+    }
 }