+ const struct rset_control *control;
+ struct rset_key_control *keycontrol;
+ int refcount; /* reference count */
+ void *priv; /* stuff private to the given type of rset */
+ NMEM nmem; /* nibble memory for various allocs */
+ RSFD free_list; /* all rfd's allocated but not currently in use */
+ RSFD use_list; /* all rfd's in use */
+ int scope; /* On what level do we count hits and compare them? */
+ TERMID term; /* the term thing for ranking etc */
+ int no_children;
+ RSET *children;
+ zint hits_limit;
+ zint hits_count;
+ zint hits_round;
+ int hits_approx;
+} rset;
+/* rset is a "virtual base class", which will never exist on its own
+ * all instances are rsets of some specific type, like rsisamb, or rsbool
+ * They keep their own stuff behind the priv pointer. */
+
+/* On the old sysno-seqno type isams, the scope was hard-coded to be 2.
+ * This means that we count hits on the sysno level, and when matching an
+ * 'and', we consider it a match if both term occur within the same sysno.
+ * In more complex isams we can specify on what level we wish to do the
+ * matching and counting of hits. For example, we can have book / chapter /
+ * verse, and a seqno. Scope 2 means then "give me all verses that match",
+ * 3 would be chapters, 4 books.
+ * The resolution tells how much of the occurences we need to return. If we
+ * are doing some sort of proximity, we need to get the seqnos of all
+ * occurences, whereas if we are only counting hits, we do not need anything
+ * below the scope. Again 1 is seqnos, 2 sysnos (or verses), 3 books, etc.
+ */
+
+RSFD rfd_create_base(RSET rs);
+int rfd_is_last(RSFD rfd);
+
+RSET rset_create_base(const struct rset_control *sel,
+ NMEM nmem,
+ struct rset_key_control *kcontrol,
+ int scope,
+ TERMID term,
+ int no_children, RSET *children);
+
+void rset_delete(RSET rs);
+RSET rset_dup (RSET rs);
+void rset_close(RSFD rfd);