new primitives trie_get_first_entry/2 and trie_get_last_entry/2 in tries module

library/tries.yap

@@ -14,7 +14,10 @@
 		  trie_put_entry/3,
 		  trie_check_entry/3,
 		  trie_get_entry/2,
+		  trie_get_first_entry/2,
+		  trie_get_last_entry/2,
 		  trie_traverse/2,
+		  trie_traverse/3,
 		  trie_remove_entry/1,
 		  trie_remove_subtree/1,
 		  trie_join/2,
@@ -46,4 +49,6 @@ trie_dup(Trie, CopyTrie) :-
 	trie_open(CopyTrie),
 	trie_join(CopyTrie, Trie).
 
-
+trie_traverse(Trie, Ref) :- 
+	trie_get_first_entry(Trie, InitRef),
+        (Ref = InitRef ; trie_traverse(Trie, InitRef, Ref)).

library/tries/base_tries.c

@@ -164,10 +164,28 @@ YAP_Term trie_get_entry(TrData data) {
 
 
 inline
-TrData trie_traverse_init(TrEntry trie) {
+TrData trie_get_first_entry(TrEntry trie) {
+  TrData data;
+  
+  data = TrEntry_first_data(trie);
+  return data;
+}
+
+
+inline
+TrData trie_get_last_entry(TrEntry trie) {
+  TrData data;
+  
+  data = TrEntry_last_data(trie);
+  return data;
+}
+
+
+inline
+TrData trie_traverse_init(TrEntry trie, TrData init_data) {
   TrData data;
 
-  data = TrEntry_first_data(trie);
+  data = TrData_next(init_data);
   TrEntry_traverse_data(trie) = data;
   return data;
 }

library/tries/base_tries.h

@@ -110,7 +110,9 @@ inline YAP_Int  trie_get_mode(void);
 inline TrData   trie_put_entry(TrEntry trie, YAP_Term entry);
 inline TrData   trie_check_entry(TrEntry trie, YAP_Term entry);
 inline YAP_Term trie_get_entry(TrData data);
-inline TrData   trie_traverse_init(TrEntry trie);
+inline TrData   trie_get_first_entry(TrEntry trie);
+inline TrData   trie_get_last_entry(TrEntry trie);
+inline TrData   trie_traverse_init(TrEntry trie, TrData init_data);
 inline TrData   trie_traverse_cont(TrEntry trie);
 inline void     trie_remove_entry(TrData data);
 inline void     trie_remove_subtree(TrData data);

library/tries/tries.c

@@ -31,6 +31,8 @@ static int p_trie_mode(void);
 static int p_trie_put_entry(void);
 static int p_trie_check_entry(void);
 static int p_trie_get_entry(void);
+static int p_trie_get_first_entry(void);
+static int p_trie_get_last_entry(void);
 static int p_trie_traverse_init(void);
 static int p_trie_traverse_cont(void);
 static int p_trie_remove_entry(void);
@@ -70,7 +72,9 @@ void init_tries(void) {
   YAP_UserCPredicate("trie_put_entry", p_trie_put_entry, 3);
   YAP_UserCPredicate("trie_check_entry", p_trie_check_entry, 3);
   YAP_UserCPredicate("trie_get_entry", p_trie_get_entry, 2);
-  YAP_UserBackCPredicate("trie_traverse", p_trie_traverse_init, p_trie_traverse_cont, 2, 0);
+  YAP_UserCPredicate("trie_get_first_entry", p_trie_get_first_entry, 2);
+  YAP_UserCPredicate("trie_get_last_entry", p_trie_get_last_entry, 2);
+  YAP_UserBackCPredicate("trie_traverse", p_trie_traverse_init, p_trie_traverse_cont, 3, 0);
   YAP_UserCPredicate("trie_remove_entry", p_trie_remove_entry, 1);
   YAP_UserCPredicate("trie_remove_subtree", p_trie_remove_subtree, 1);
   YAP_UserCPredicate("trie_join", p_trie_join, 2);
@@ -330,30 +334,74 @@ static int p_trie_get_entry(void) {
 #undef arg_entry
 
 
-/* trie_traverse(-Trie,+Ref) */
+/* trie_get_first_entry(-Trie,+Ref) */
 #define arg_trie YAP_ARG1
-#define arg_ref   YAP_ARG2
+#define arg_ref  YAP_ARG2
-static int p_trie_traverse_init(void) {
+static int p_trie_get_first_entry(void) {
   TrData data;
 
-  /* check arg */
+  /* check args */
   if (!YAP_IsIntTerm(arg_trie)) 
     return FALSE;
 
-  /* traverse trie */
+  /* get first trie entry */
-  if (!(data = trie_traverse_init((TrEntry) YAP_IntOfTerm(arg_trie)))) {
+  if (!(data = trie_get_first_entry((TrEntry) YAP_IntOfTerm(arg_trie))))
-    YAP_cut_fail();
     return FALSE;
-  }
   return YAP_Unify(arg_ref, YAP_MkIntTerm((YAP_Int) data));
 }
 #undef arg_trie
 #undef arg_ref
 
 
-/* trie_traverse(-Trie,+Ref) */
+/* trie_get_last_entry(-Trie,+Ref) */
 #define arg_trie YAP_ARG1
-#define arg_ref   YAP_ARG2
+#define arg_ref  YAP_ARG2
+static int p_trie_get_last_entry(void) {
+  TrData data;
+
+  /* check args */
+  if (!YAP_IsIntTerm(arg_trie)) 
+    return FALSE;
+
+  /* get last trie entry */
+  if (!(data = trie_get_last_entry((TrEntry) YAP_IntOfTerm(arg_trie))))
+    return FALSE;
+  return YAP_Unify(arg_ref, YAP_MkIntTerm((YAP_Int) data));
+}
+#undef arg_trie
+#undef arg_ref
+
+
+/* trie_traverse(-Trie,-FirstRef,+Ref) */
+#define arg_trie     YAP_ARG1
+#define arg_init_ref YAP_ARG2
+#define arg_ref      YAP_ARG3
+static int p_trie_traverse_init(void) {
+  TrData data;
+
+  /* check args */
+  if (!YAP_IsIntTerm(arg_trie)) 
+    return FALSE;
+  if (!YAP_IsIntTerm(arg_init_ref)) 
+    return FALSE;
+
+  /* traverse trie */
+  if (!(data = trie_traverse_init((TrEntry) YAP_IntOfTerm(arg_trie), (TrData) YAP_IntOfTerm(arg_init_ref)))) {
+    printf("cut fail no init!!!\n");
+    YAP_cut_fail();
+    return FALSE;
+  }
+  return YAP_Unify(arg_ref, YAP_MkIntTerm((YAP_Int) data));
+}
+#undef arg_trie
+#undef arg_init_ref
+#undef arg_ref
+
+
+/* trie_traverse(-Trie,-FirstRef,+Ref) */
+#define arg_trie     YAP_ARG1
+#define arg_init_ref YAP_ARG2
+#define arg_ref      YAP_ARG3
 static int p_trie_traverse_cont(void) {
   TrData data;
 
@@ -365,6 +413,7 @@ static int p_trie_traverse_cont(void) {
   return YAP_Unify(arg_ref, YAP_MkIntTerm((YAP_Int) data));
 }
 #undef arg_trie
+#undef arg_init_ref
 #undef arg_ref