X-Git-Url: http://jsfdemo.indexdata.com/?a=blobdiff_plain;f=include%2Fyaz%2Fnfa.h;h=6f3ba4ebd797afebc13b5ced2d77b09a06b0e4c4;hb=b77f4b5c2b191b83cf3f213faa8b6b263e36fea4;hp=e89a405e7665304c88144e72a5d4cbdb7c4cd7da;hpb=4d994a119a1949522fe229270983ba1b1b399c6a;p=yaz-moved-to-github.git

diff --git a/include/yaz/nfa.h b/include/yaz/nfa.h
index e89a405..6f3ba4e 100644
--- a/include/yaz/nfa.h
+++ b/include/yaz/nfa.h
@@ -1,6 +1,6 @@
 /*  Copyright (C) 2006, Index Data ApS
  *  See the file LICENSE for details.
- *  $Id: nfa.h,v 1.1 2006-05-03 09:04:33 heikki Exp $
+ *  $Id: nfa.h,v 1.3 2006-05-03 13:47:35 heikki Exp $
  */
 
 /**
@@ -86,29 +86,29 @@ void *yaz_nfa_get_result(
          yaz_nfa *n /** The NFA itself */, 
          yaz_nfa_state *s /** The state whose result you want */);
 
-/** \brief Set the backref number to a state.
+/** \brief Set a backref point to a state.
  * 
- *  Each state can be the beginning and/or ending of a backref
- *  sequence. This call sets those flags in the states. After matching,
- *  we can get hold of the backrefs that matched, and use them in our
- *  translations.
+ *  Each state can be the beginning and/or ending point of a backref
+ *  sequence. This call sets one of those flags in the state. After 
+ *  matching, we can get hold of the backrefs that matched, and use 
+ *  them in our translations. The numbering of backrefs start at 1, 
+ *  not zero!
  *
  *  \param n   the nfa
  *  \param s   the state to add to
  *  \param backref_number is the number of the back reference. 0 for clearing
  *  \param is_start is 1 for start of the backref, 0 for end
- *  \return
- *     0 for OK
- *     1 if the backref is already set
- *     
+ *  \retval   0 for OK
+ *  \retval   1 if the backref is already set
+ *  \retval   2 for ending a backref that has not been started
  *     
  */
 
-int yaz_nfa_set_backref(yaz_nfa *n, yaz_nfa_state *s,
+int yaz_nfa_set_backref_point(yaz_nfa *n, yaz_nfa_state *s,
         int backref_number,
         int is_start );
 
-/** \brief Get the backref number of a state.
+/** \brief Get the backref point of a state
  * 
  *  \param n   the nfa
  *  \param s   the state to add to
@@ -116,7 +116,7 @@ int yaz_nfa_set_backref(yaz_nfa *n, yaz_nfa_state *s,
  *  \return the backref number associated with the state, or 0 if none.
  */
 
-int yaz_nfa_get_backref(yaz_nfa *n, yaz_nfa_state *s,
+int yaz_nfa_get_backref_point(yaz_nfa *n, yaz_nfa_state *s,
         int is_start );
 
 /**  \brief Add a transition to the NFA.
@@ -197,6 +197,31 @@ int yaz_nfa_match(yaz_nfa *n, yaz_nfa_char **inbuff, size_t incharsleft,
 #define YAZ_NFA_OVERRUN 2
 #define YAZ_NFA_LOOP 3
 
+/** \brief Get a back reference after a successfull match.
+ *
+ *  \param n   the nfa
+ *  \param backref_no  the number of the backref to get
+ *  \param begin  beginning of the matching substring
+ *  \param end    end of the matching substring
+ *
+ * Returns pointers to the beginning and end of a backref, or null
+ * pointers if one endpoint not met.  Those pointers point to the
+ * original buffer that was matched, so the caller will not have to
+ * worry about freeing anything special.
+ *
+ * It is technically possible to create NFAs that meet the start but 
+ * not the end of a backref.  It is up to the caller to decide how
+ * to handle such a situation.
+ *
+ * \retval 0 OK
+ * \retval 1 no match
+ * \retval 2 no such backref
+ */
+
+int yaz_nfa_get_backref( yaz_nfa *n, 
+        int backref_no,
+        yaz_nfa_char **start,
+        yaz_nfa_char **end );
 
 /** \brief Get the first state of the NFA. 
  *