sieve: improve argument/tag runtime access API

* include/mailutils/sieve.h (mu_sieve_data_type): Remove SVT_VALUE_LIST.
(mu_sieve_value_storage): Named union for use in mu_sieve_value_t; remove
the tag field.
(mu_sieve_tag_lookup): Change prototype.
(mu_sieve_value_get): Change prototype.
(mu_sieve_value_get_optional)
(mu_sieve_value_get_untyped): New functions.
(mu_sieve_arg_error): Removed proto.

* libmu_sieve/sieve.y: Remove SVT_VALUE_LIST support.
* libmu_sieve/util.c (mu_sieve_value_create)
(mu_sieve_type_str,mu_sieve_vlist_do): Remove SVT_VALUE_LIST support.
(mu_sieve_value_get): Rewrite.
(mu_sieve_value_get_untyped)
(mu_sieve_value_get_optional): New functions.
(mu_sieve_arg_error): Remove.
(mu_sieve_tag_lookup): Rewrite.
(mu_sieve_tag_lookup_untyped): New function.

* doc/texinfo/libmu_sieve.texi: Update.

libmu_sieve/tests.c
libmu_sieve/actions.c
libmu_sieve/extensions/editheader.c
libmu_sieve/extensions/list.c
libmu_sieve/extensions/moderator.c
libmu_sieve/extensions/pipe.c
libmu_sieve/extensions/spamd.c
libmu_sieve/extensions/timestamp.c
libmu_sieve/extensions/vacation.c
libmu_sieve/relational.c

examples/numaddr.c

16 files changed, 230 insertions, 302 deletions

diff --git a/doc/texinfo/libmu_sieve.texi b/doc/texinfo/libmu_sieve.texi
index d4c44515f..1d673a87c 100644
--- a/doc/texinfo/libmu_sieve.texi
+++ b/doc/texinfo/libmu_sieve.texi
@@ -85,9 +85,6 @@ A sieve tag. See @code{mu_sieve_runtime_tag_t} below.
 @item SVT_IDENT
 A character string representing an identifier. 
 
-@item SVT_VALUE_LIST
-A @code{mu_list_t}. Each item in this list is of @code{mu_sieve_value_t} type.
-
 @item SVT_POINTER
 An opaque pointer.
 @end table
@@ -128,7 +125,6 @@ The numeric value is kept in @code{number} member.
 The string is kept in @code{string} member.
 
 @item SVT_STRING_LIST
-@itemx SVT_VALUE_LIST
 The list itself is pointed to by @code{list} member
 
 @item SVT_TAG
diff --git a/examples/numaddr.c b/examples/numaddr.c
index 66602ad3d..b0737938c 100644
--- a/examples/numaddr.c
+++ b/examples/numaddr.c
@@ -80,37 +80,26 @@ _count_items (void *item, void *data)
 static int
 numaddr_test (mu_sieve_machine_t mach, mu_list_t args, mu_list_t tags)
 {
-  mu_sieve_value_t *h, *v;
+  mu_sieve_value_t *h;
   struct val_ctr vc;
   int rc;
   
   /* Retrieve required arguments: */
   /* First argument: list of header names */
-  h = mu_sieve_value_get (args, 0);
-  if (!h)
-    {
-      mu_sieve_error (mach, "numaddr: can't get argument 1");
-      mu_sieve_abort (mach);
-    }
+  h = mu_sieve_value_get_untyped (mach, args, 0);
   /* Second argument: Limit on the number of addresses */
-  v = mu_sieve_value_get (args, 1);
-  if (!v)
-    {
-      mu_sieve_error (mach, "numaddr: can't get argument 2");
-      mu_sieve_abort (mach);
-    }
+  mu_sieve_value_get (mach, args, 1, SVT_NUMBER, &vc.limit);
 
   /* Fill in the val_ctr structure */
   mu_message_get_header (mu_sieve_get_message (mach), &vc.hdr);
   vc.count = 0;
-  vc.limit = v->v.number;
 
   /* Count the addresses */
   rc = mu_sieve_vlist_do (h, _count_items, &vc);
 
   /* Here rc >= 1 iff the counted number of addresses is greater or equal
      to vc.limit. If `:under' tag was given we reverse the return value */
-  if (mu_sieve_tag_lookup (tags, "under", NULL))
+  if (mu_sieve_tag_lookup (mach, tags, "under", SVT_VOID, NULL))
     rc = !rc;
 
   return rc;
diff --git a/include/mailutils/sieve.h b/include/mailutils/sieve.h
index 019ee617b..4fc91c230 100644
--- a/include/mailutils/sieve.h
+++ b/include/mailutils/sieve.h
@@ -57,24 +57,24 @@ typedef enum
   SVT_STRING_LIST,
   SVT_TAG,
   SVT_IDENT,
-  SVT_VALUE_LIST,
   SVT_POINTER
 }
 mu_sieve_data_type;
 
 typedef struct mu_sieve_runtime_tag mu_sieve_runtime_tag_t;
 
+union mu_sieve_value_storage
+{
+  char *string;
+  size_t number;
+  mu_list_t list;
+  void *ptr;
+};
+
 typedef struct
 {
   mu_sieve_data_type type;
-  union
-  {
-    char *string;
-    size_t number;
-    mu_list_t list;
-    mu_sieve_runtime_tag_t *tag;
-    void *ptr;
-  } v;
+  union mu_sieve_value_storage v;
 } mu_sieve_value_t;
 
 typedef struct
@@ -184,8 +184,12 @@ mu_sieve_relcmp_t mu_sieve_get_relcmp (mu_sieve_machine_t mach,
 
 void mu_sieve_require (mu_sieve_machine_t mach, mu_list_t slist);
 
-int mu_sieve_tag_lookup (mu_list_t taglist, char *name,
-			 mu_sieve_value_t ** arg);
+int mu_sieve_tag_lookup (mu_sieve_machine_t mach,
+			 mu_list_t taglist, char *name,
+			 mu_sieve_data_type type, void *ret);
+int mu_sieve_tag_lookup_untyped (mu_sieve_machine_t mach, mu_list_t taglist,
+				 char *name, mu_sieve_value_t **ret);
+  
 int mu_sieve_load_ext (mu_sieve_machine_t mach, const char *name);
 int mu_sieve_match_part_checker (mu_sieve_machine_t mach,
 				 const char *name, mu_list_t tags,
@@ -193,8 +197,16 @@ int mu_sieve_match_part_checker (mu_sieve_machine_t mach,
 int mu_sieve_match_part_checker (mu_sieve_machine_t mach,
 				 const char *name, mu_list_t tags,
 				 mu_list_t args);
-/* Operations in value lists */
-mu_sieve_value_t *mu_sieve_value_get (mu_list_t vlist, size_t index);
+/* Operations on value lists */
+mu_sieve_value_t *mu_sieve_value_get_optional (mu_sieve_machine_t mach,
+					       mu_list_t vlist,
+					       size_t index);
+mu_sieve_value_t *mu_sieve_value_get_untyped (mu_sieve_machine_t mach,
+					      mu_list_t vlist,
+					      size_t index);
+int mu_sieve_value_get (mu_sieve_machine_t mach, mu_list_t vlist,
+			size_t index,
+			mu_sieve_data_type type, void *ret);
 int mu_sieve_vlist_do (mu_sieve_value_t *val, mu_list_action_t ac,
 		       void *data);
 int mu_sieve_vlist_compare (mu_sieve_value_t *a, mu_sieve_value_t *b,
@@ -251,7 +263,6 @@ void mu_sieve_log_action (mu_sieve_machine_t mach, const char *action,
 			  const char *fmt, ...)
 			  MU_PRINTFLIKE(3,4);
 void mu_sieve_abort (mu_sieve_machine_t mach);
-void mu_sieve_arg_error (mu_sieve_machine_t mach, int n);
 
 int mu_sieve_is_dry_run (mu_sieve_machine_t mach);
 const char *mu_sieve_type_str (mu_sieve_data_type type);
diff --git a/libmu_sieve/actions.c b/libmu_sieve/actions.c
index 84bd36849..f6c37f789 100644
--- a/libmu_sieve/actions.c
+++ b/libmu_sieve/actions.c
@@ -79,32 +79,29 @@ sieve_action_fileinto (mu_sieve_machine_t mach, mu_list_t args, mu_list_t tags)
 {
   int rc;
   int mbflags = 0;
-  mu_sieve_value_t *opt;
-  mu_sieve_value_t *val = mu_sieve_value_get (args, 0);
-  if (!val)
-    {
-      mu_sieve_error (mach, _("cannot get filename!"));
-      mu_sieve_abort (mach);
-    }
+  char *filename;
+  char *perms;
 
-  if (mu_sieve_tag_lookup (tags, "permissions", &opt))
+  mu_sieve_value_get (mach, args, 0, SVT_STRING, &filename);
+
+  if (mu_sieve_tag_lookup (mach, tags, "permissions", SVT_STRING, &perms))
     {
       const char *p;
       
-      if (mu_parse_stream_perm_string (&mbflags, opt->v.string, &p))
+      if (mu_parse_stream_perm_string (&mbflags, perms, &p))
 	{
 	  /* Should not happen, but anyway... */
 	  mu_sieve_error (mach, _("invalid permissions (near %s)"), p);
-	  return 1;
+	  mu_sieve_abort (mach);
 	}
     }
   
   mu_sieve_log_action (mach, "FILEINTO",
-		       _("delivering into %s"), val->v.string);
+		       _("delivering into %s"), filename);
   if (mu_sieve_is_dry_run (mach))
     return 0;
 
-  rc = mu_message_save_to_mailbox (mach->msg, val->v.string, mbflags);
+  rc = mu_message_save_to_mailbox (mach->msg, filename, mbflags);
   if (rc)
     mu_sieve_error (mach, _("cannot save to mailbox: %s"),
 		    mu_strerror (rc));
@@ -293,18 +290,14 @@ sieve_action_reject (mu_sieve_machine_t mach, mu_list_t args, mu_list_t tags)
   char *addrtext;
   mu_address_t from, to;
   mu_header_t hdr;
+  char *text;
   
-  mu_sieve_value_t *val = mu_sieve_value_get (args, 0);
-  if (!val)
-    {
-      mu_sieve_error (mach, _("reject: cannot get text!"));
-      mu_sieve_abort (mach);
-    }
+  mu_sieve_value_get (mach, args, 0, SVT_STRING, &text);
   mu_sieve_log_action (mach, "REJECT", NULL);  
   if (mu_sieve_is_dry_run (mach))
     return 0;
 
-  rc = build_mime (&mime, mach->msg, val->v.string);
+  rc = build_mime (&mime, mach->msg, text);
 
   mu_mime_get_message (mime, &newmsg);
   mu_message_unref (newmsg);
@@ -413,25 +406,21 @@ sieve_action_redirect (mu_sieve_machine_t mach, mu_list_t args, mu_list_t tags)
   int rc;
   char *fromaddr, *p;
   mu_mailer_t mailer = mu_sieve_get_mailer (mach);
+  char *addrstr;
   
-  mu_sieve_value_t *val = mu_sieve_value_get (args, 0);
-  if (!val)
-    {
-      mu_sieve_error (mach, _("cannot get address!"));
-      mu_sieve_abort (mach);
-    }
+  mu_sieve_value_get (mach, args, 0, SVT_STRING, &addrstr);
 
-  rc = mu_address_create (&addr, val->v.string);
+  rc = mu_address_create (&addr, addrstr);
   if (rc)
     {
       mu_sieve_error (mach,
 		      _("%lu: parsing recipient address `%s' failed: %s"),
 		      (unsigned long) mu_sieve_get_message_num (mach),
-		      val->v.string, mu_strerror (rc));
+		      addrstr, mu_strerror (rc));
       return 1;
     }
   
-  mu_sieve_log_action (mach, "REDIRECT", _("to %s"), val->v.string);
+  mu_sieve_log_action (mach, "REDIRECT", _("to %s"), addrstr);
   if (mu_sieve_is_dry_run (mach))
     return 0;
 
diff --git a/libmu_sieve/comparator.c b/libmu_sieve/comparator.c
index d7be199fe..03fe4038c 100644
--- a/libmu_sieve/comparator.c
+++ b/libmu_sieve/comparator.c
@@ -288,8 +288,7 @@ mu_sieve_match_part_checker (mu_sieve_machine_t mach,
 
           matchtype = MU_SIEVE_MATCH_LAST; /* to not leave it undefined */
 	  compfun = comp_false;
-	  val = mu_sieve_value_get (args, 1);
-	  if (!val)
+	  if (mu_list_get (args, 1, (void**) &val))
 	    return 1; /* shouldn't happen */
 	  /* NOTE: Type of v is always SVT_STRING_LIST */
 	  mu_list_count (val->v.list, &count);
diff --git a/libmu_sieve/extensions/editheader.c b/libmu_sieve/extensions/editheader.c
index ba4d0c093..4ec7c1d01 100644
--- a/libmu_sieve/extensions/editheader.c
+++ b/libmu_sieve/extensions/editheader.c
@@ -33,32 +33,14 @@
 int
 sieve_addheader (mu_sieve_machine_t mach, mu_list_t args, mu_list_t tags)
 {
-  mu_sieve_value_t *val;
   const char *field_name;
   const char *field_value;
   mu_message_t msg;
   mu_header_t hdr;
   int rc;
   
-  val = mu_sieve_value_get (args, 0);
-  if (!val)
-    {
-      mu_sieve_error (mach, "%lu: %s",
-		      (unsigned long) mu_sieve_get_message_num (mach),
-		      _("cannot get field name"));
-      mu_sieve_abort (mach);
-    }
-  field_name = val->v.string;
-
-  val = mu_sieve_value_get (args, 1);
-  if (!val)
-    {
-      mu_sieve_error (mach, "%lu: %s",
-		      (unsigned long) mu_sieve_get_message_num (mach),
-		      _("cannot get field value"));
-      mu_sieve_abort (mach);
-    }
-  field_value = val->v.string;
+  mu_sieve_value_get (mach, args, 0, SVT_STRING, &field_name);
+  mu_sieve_value_get (mach, args, 1, SVT_STRING, &field_value);
 
   mu_sieve_log_action (mach, "ADDHEADER", "%s: %s", field_name, field_value);
 
@@ -76,7 +58,7 @@ sieve_addheader (mu_sieve_machine_t mach, mu_list_t args, mu_list_t tags)
       mu_sieve_abort (mach);
     }
 
-  rc = (mu_sieve_tag_lookup (tags, "last", NULL) ?
+  rc = (mu_sieve_tag_lookup (mach, tags, "last", SVT_VOID, NULL) ?
 	mu_header_append : mu_header_prepend) (hdr, field_name, field_value);
   if (rc)
     {
@@ -105,19 +87,10 @@ sieve_deleteheader (mu_sieve_machine_t mach, mu_list_t args, mu_list_t tags)
   int rc;
   mu_sieve_comparator_t comp;
   mu_iterator_t itr;
-  unsigned long i, idx = 0;
+  size_t i, idx = 0;
   
-  val = mu_sieve_value_get (args, 0);
-  if (!val)
-    {
-      mu_sieve_error (mach, "%lu: %s",
-		      (unsigned long) mu_sieve_get_message_num (mach),
-		      _("cannot get field name"));
-      mu_sieve_abort (mach);
-    }
-  field_name = val->v.string;
-
-  val = mu_sieve_value_get (args, 1);
+  mu_sieve_value_get (mach, args, 0, SVT_STRING, &field_name);
+  val = mu_sieve_value_get_optional (mach, args, 1);
   if (!val)
     {
       field_pattern = NULL;
@@ -169,15 +142,14 @@ sieve_deleteheader (mu_sieve_machine_t mach, mu_list_t args, mu_list_t tags)
     }
 
   mu_header_get_iterator (hdr, &itr);
-  if (mu_sieve_tag_lookup (tags, "last", NULL))
+  if (mu_sieve_tag_lookup (mach, tags, "last", SVT_VOID, NULL))
     {
       int backwards = 1;
       mu_iterator_ctl (itr, mu_itrctl_set_direction, &backwards);
     }
   comp = mu_sieve_get_comparator (mach, tags);
 
-  if (mu_sieve_tag_lookup (tags, "index", &val))
-    idx = val->v.number;
+  mu_sieve_tag_lookup (mach, tags, "index", SVT_NUMBER, &idx);
   
   for (i = 0, mu_iterator_first (itr); !mu_iterator_is_done (itr);
        mu_iterator_next (itr))
diff --git a/libmu_sieve/extensions/list.c b/libmu_sieve/extensions/list.c
index ccde22d9c..fd186603e 100644
--- a/libmu_sieve/extensions/list.c
+++ b/libmu_sieve/extensions/list.c
@@ -147,30 +147,17 @@ list_retrieve_header (void *item, void *data, int idx, char **pval)
 static int
 list_test (mu_sieve_machine_t mach, mu_list_t args, mu_list_t tags)
 {
-  mu_sieve_value_t *h, *v, *arg;
+  mu_sieve_value_t *h, *v;
   mu_sieve_comparator_t comp = mu_sieve_get_comparator (mach, tags);
   struct header_closure clos;
   int result;
 
   memset (&clos, 0, sizeof clos);
-  if (mu_sieve_tag_lookup (tags, "delim", &arg))
-    clos.delim = arg->v.string;
-  else
+  if (!mu_sieve_tag_lookup (mach, tags, "delim", SVT_STRING, &clos.delim))
     clos.delim = ",";
   
-  h = mu_sieve_value_get (args, 0);
-  if (!h)
-    {
-      mu_sieve_arg_error (mach, 1);
-      mu_sieve_abort (mach);
-    }
-  v = mu_sieve_value_get (args, 1);
-  if (!v)
-    {
-      mu_sieve_arg_error (mach, 2);
-      mu_sieve_abort (mach);
-    }
-
+  h = mu_sieve_value_get_untyped (mach, args, 0);
+  v = mu_sieve_value_get_untyped (mach, args, 1);
   mu_message_get_header (mu_sieve_get_message (mach), &clos.header);
   result = mu_sieve_vlist_compare (h, v, comp,
 				   mu_sieve_get_relcmp (mach, tags),
diff --git a/libmu_sieve/extensions/moderator.c b/libmu_sieve/extensions/moderator.c
index b19d0edab..7d16cefaa 100644
--- a/libmu_sieve/extensions/moderator.c
+++ b/libmu_sieve/extensions/moderator.c
@@ -80,9 +80,9 @@ moderator_filter_message (mu_sieve_machine_t mach, mu_list_t tags,
   int rc;
   mu_sieve_machine_t newmach;
   mu_attribute_t attr;
-  mu_sieve_value_t *arg;
+  char *arg;
   
-  if (mu_sieve_tag_lookup (tags, "source", &arg))
+  if (mu_sieve_tag_lookup (mach, tags, "source", SVT_STRING, &arg))
     {
       rc = mu_sieve_machine_inherit (mach, &newmach);
       if (rc)
@@ -97,11 +97,11 @@ moderator_filter_message (mu_sieve_machine_t mach, mu_list_t tags,
 	   ...
       */
       
-      rc = mu_sieve_compile (newmach, arg->v.string);
+      rc = mu_sieve_compile (newmach, arg);
       if (rc)
-	mu_sieve_error (mach, _("cannot compile source `%s'"), arg->v.string);
+	mu_sieve_error (mach, _("cannot compile source `%s'"), arg);
     }
-  else if (mu_sieve_tag_lookup (tags, "program", &arg))
+  else if (mu_sieve_tag_lookup (mach, tags, "program", SVT_STRING, &arg))
     {
       struct mu_locus locus;
       
@@ -114,7 +114,7 @@ moderator_filter_message (mu_sieve_machine_t mach, mu_list_t tags,
 	}
       mu_sieve_get_locus (mach, &locus);
       rc = mu_sieve_compile_buffer (newmach,
-				    arg->v.string, strlen (arg->v.string),
+				    arg, strlen (arg),
 				    locus.mu_file, locus.mu_line);
       if (rc)
 	mu_sieve_error (mach, _("cannot compile subprogram"));
@@ -303,7 +303,6 @@ moderator_action (mu_sieve_machine_t mach, mu_list_t args, mu_list_t tags)
     {
       mu_message_t request;
       char *from = NULL;
-      mu_sieve_value_t *arg;
       
       if ((rc = moderator_message_get_part (mach, msg, 3, &request)))
 	{
@@ -312,14 +311,13 @@ moderator_action (mu_sieve_machine_t mach, mu_list_t args, mu_list_t tags)
 	  mu_sieve_abort (mach);
 	}
 
-      if (mu_sieve_tag_lookup (tags, "address", &arg))
-	from = arg->v.string;
+      mu_sieve_tag_lookup (mach, tags, "address", SVT_STRING, &from);
       
       if (moderator_discard_message (mach, request, from))
 	discard = 0;
       else
 	{
-	  if (!mu_sieve_tag_lookup (tags, "keep", NULL))
+	  if (!mu_sieve_tag_lookup (mach, tags, "keep", SVT_VOID, NULL))
 	    {
 	      mu_attribute_t attr = 0;
 
diff --git a/libmu_sieve/extensions/pipe.c b/libmu_sieve/extensions/pipe.c
index 045c5a81d..d7eaadd00 100644
--- a/libmu_sieve/extensions/pipe.c
+++ b/libmu_sieve/extensions/pipe.c
@@ -87,7 +87,6 @@ sieve_pipe (mu_sieve_machine_t mach, mu_list_t args, mu_list_t tags, int test)
   int retval = 0;
   int rc, result;
   mu_message_t msg;
-  mu_sieve_value_t *val;
   char *cmd;
   mu_stream_t pstr;
   mu_envelope_t env;
@@ -95,15 +94,7 @@ sieve_pipe (mu_sieve_machine_t mach, mu_list_t args, mu_list_t tags, int test)
   const char *error_arg = NULL;
   int pipe_mask = 0;
   
-  val = mu_sieve_value_get (args, 0);
-  if (!val)
-    {
-      mu_sieve_error (mach, "%lu: %s",
-		      (unsigned long) mu_sieve_get_message_num (mach),
-		      _("cannot get command!"));
-      mu_sieve_abort (mach);
-    }
-  cmd = val->v.string;
+  mu_sieve_value_get (mach, args, 0, SVT_STRING, &cmd);
 
   if (mu_sieve_is_dry_run (mach))
     return 0;
@@ -111,11 +102,11 @@ sieve_pipe (mu_sieve_machine_t mach, mu_list_t args, mu_list_t tags, int test)
   msg = mu_sieve_get_message (mach);
   mu_message_get_envelope (msg, &env);
 
-  if (mu_sieve_tag_lookup (tags, "envelope", NULL))
+  if (mu_sieve_tag_lookup (mach, tags, "envelope", SVT_VOID, NULL))
     pipe_mask |= PIPE_ENVELOPE;
-  if (mu_sieve_tag_lookup (tags, "header", NULL))
+  if (mu_sieve_tag_lookup (mach, tags, "header", SVT_VOID, NULL))
     pipe_mask |= PIPE_HEADERS;
-  if (mu_sieve_tag_lookup (tags, "body", NULL))
+  if (mu_sieve_tag_lookup (mach, tags, "body", SVT_VOID, NULL))
     pipe_mask |= PIPE_BODY;
   if (pipe_mask == 0)
     pipe_mask = PIPE_ALL;
@@ -193,6 +184,7 @@ sieve_pipe (mu_sieve_machine_t mach, mu_list_t args, mu_list_t tags, int test)
     {
       int code = 0;
       int status;
+      size_t n;
       
       rc = mu_stream_ioctl (pstr, MU_IOCTL_PROGSTREAM,
 			    MU_IOCTL_PROG_STATUS, &status);
@@ -202,8 +194,8 @@ sieve_pipe (mu_sieve_machine_t mach, mu_list_t args, mu_list_t tags, int test)
 	  mu_sieve_abort (mach);
 	}
 
-      if (mu_sieve_tag_lookup (tags, "exit", &val))
-	code = val->v.number;
+      if (mu_sieve_tag_lookup (mach, tags, "exit", SVT_NUMBER, &n))
+	code = n;
       if (result == 0)
 	retval = code == 0;
       else if (result == MU_ERR_PROCESS_EXITED)
@@ -211,8 +203,9 @@ sieve_pipe (mu_sieve_machine_t mach, mu_list_t args, mu_list_t tags, int test)
       else if (result == MU_ERR_PROCESS_SIGNALED)
 	{
 	  int signo = WTERMSIG (status);
-	  if (mu_sieve_tag_lookup (tags, "signal", &val))
-	    retval = signo == val->v.number;
+	  size_t n;
+	  if (mu_sieve_tag_lookup (mach, tags, "signal", SVT_NUMBER, &n))
+	    retval = signo == n;
 	  else
 	    {
 	      mu_stream_destroy (&pstr);
diff --git a/libmu_sieve/extensions/spamd.c b/libmu_sieve/extensions/spamd.c
index 290d8b8aa..4e5fea1ff 100644
--- a/libmu_sieve/extensions/spamd.c
+++ b/libmu_sieve/extensions/spamd.c
@@ -362,9 +362,10 @@ spamd_test (mu_sieve_machine_t mach, mu_list_t args, mu_list_t tags)
   int result;
   long score, threshold, limit;
   mu_stream_t stream = NULL, null;
-  mu_sieve_value_t *arg;
   mu_message_t msg;
   char *host;
+  size_t num;
+  char *str;
   mu_header_t hdr;
   mu_debug_handle_t lev = 0;
   
@@ -380,15 +381,13 @@ spamd_test (mu_sieve_machine_t mach, mu_list_t args, mu_list_t tags)
       mu_sieve_abort (mach);
     }
   
-  if (mu_sieve_tag_lookup (tags, "host", &arg))
-    host = arg->v.string;
-  else
+  if (!mu_sieve_tag_lookup (mach, tags, "host", SVT_STRING, &host))
     host = "127.0.0.1";
   
-  if (mu_sieve_tag_lookup (tags, "port", &arg))
-    result = spamd_connect_tcp (mach, &stream, host, arg->v.number);
-  else if (mu_sieve_tag_lookup (tags, "socket", &arg))
-    result = spamd_connect_socket (mach, &stream, arg->v.string);
+  if (mu_sieve_tag_lookup (mach, tags, "port", SVT_NUMBER, &num))
+    result = spamd_connect_tcp (mach, &stream, host, num);
+  else if (mu_sieve_tag_lookup (mach, tags, "socket", SVT_STRING, &str))
+    result = spamd_connect_socket (mach, &stream, str);
   else
     result = spamd_connect_tcp (mach, &stream, host, DEFAULT_SPAMD_PORT);
   if (result) /* spamd_connect_ already reported error */
@@ -422,8 +421,8 @@ spamd_test (mu_sieve_machine_t mach, mu_list_t args, mu_list_t tags)
   spamd_send_command (stream, "SYMBOLS SPAMC/1.2");
   
   spamd_send_command (stream, "Content-length: %lu", (u_long) size);
-  if (mu_sieve_tag_lookup (tags, "user", &arg))
-    spamd_send_command (stream, "User: %s", arg);
+  if (mu_sieve_tag_lookup (mach, tags, "user", SVT_STRING, &str))
+    spamd_send_command (stream, "User: %s", str);
   else
     {
       struct mu_auth_data *auth = mu_get_auth_by_uid (geteuid ());
@@ -465,14 +464,14 @@ spamd_test (mu_sieve_machine_t mach, mu_list_t args, mu_list_t tags)
 
   if (!result)
     {
-      if (mu_sieve_tag_lookup (tags, "over", &arg))
+      if (mu_sieve_tag_lookup (mach, tags, "over", SVT_STRING, &str))
 	{
-	  decode_float (&limit, arg->v.string, 3, NULL);
+	  decode_float (&limit, str, 3, NULL);
 	  result = score >= limit;
 	}
-      else if (mu_sieve_tag_lookup (tags, "under", &arg))
+      else if (mu_sieve_tag_lookup (mach, tags, "under", SVT_STRING, &str))
 	{
-	  decode_float (&limit, arg->v.string, 3, NULL);
+	  decode_float (&limit, str, 3, NULL);
 	  result = score <= limit;	  
 	}
     }
diff --git a/libmu_sieve/extensions/timestamp.c b/libmu_sieve/extensions/timestamp.c
index 56c12f23b..dd29d1f34 100644
--- a/libmu_sieve/extensions/timestamp.c
+++ b/libmu_sieve/extensions/timestamp.c
@@ -50,7 +50,8 @@
 static int
 timestamp_test (mu_sieve_machine_t mach, mu_list_t args, mu_list_t tags)
 {
-  mu_sieve_value_t *h, *v;
+  char const *hname;
+  char const *date;
   mu_header_t hdr;
   char *val;
   time_t now = time (NULL);
@@ -59,24 +60,14 @@ timestamp_test (mu_sieve_machine_t mach, mu_list_t args, mu_list_t tags)
   
   /* Retrieve required arguments: */
   /* First argument: header name */
-  h = mu_sieve_value_get (args, 0);
-  if (!h)
-    {
-      mu_sieve_arg_error (mach, 1);
-      mu_sieve_abort (mach);
-    }
+  mu_sieve_value_get (mach, args, 0, SVT_STRING, &hname);
   /* Second argument: date displacement */
-  v = mu_sieve_value_get (args, 1);
-  if (!v)
-    {
-      mu_sieve_arg_error (mach, 2);
-      mu_sieve_abort (mach);
-    }
+  mu_sieve_value_get (mach, args, 1, SVT_STRING, &date);
 
-  if (mu_parse_date (v->v.string, &tlimit, &now))
+  if (mu_parse_date (date, &tlimit, &now))
     {
       mu_sieve_error (mach, _("cannot parse date specification (%s)"),
-		   v->v.string);
+		      date);
       mu_sieve_abort (mach);
     }
 
@@ -87,7 +78,7 @@ timestamp_test (mu_sieve_machine_t mach, mu_list_t args, mu_list_t tags)
       mu_sieve_abort (mach);
     }
   
-  if (mu_header_aget_value (hdr, h->v.string, &val))
+  if (mu_header_aget_value (hdr, hname, &val))
     return 0;
 
   if (mu_parse_date (val, &tval, &now))
@@ -102,7 +93,7 @@ timestamp_test (mu_sieve_machine_t mach, mu_list_t args, mu_list_t tags)
 
   rc = tval > tlimit;
     
-  if (mu_sieve_tag_lookup (tags, "before", NULL))
+  if (mu_sieve_tag_lookup (mach, tags, "before", SVT_VOID, NULL))
     rc = !rc;  
 
   return rc;
diff --git a/libmu_sieve/extensions/vacation.c b/libmu_sieve/extensions/vacation.c
index 8b8fefc65..a3a1fc367 100644
--- a/libmu_sieve/extensions/vacation.c
+++ b/libmu_sieve/extensions/vacation.c
@@ -78,7 +78,7 @@ build_mime (mu_sieve_machine_t mach, mu_list_t tags, mu_mime_t *pmime,
       return 1;
     }
 
-  if (mu_sieve_tag_lookup (tags, "mime", NULL))
+  if (mu_sieve_tag_lookup (mach, tags, "mime", SVT_VOID, NULL))
     {
       mu_stream_t fstr;
       rc = mu_filter_create (&fstr, input, "base64",
@@ -249,7 +249,7 @@ noreply_address_p (mu_sieve_machine_t mach, mu_list_t tags, char *email)
   for (i = 0; rc == 0 && noreply_sender[i]; i++)
     rc = regex_comparator (noreply_sender[i], &rd);
 
-  if (!rc && mu_sieve_tag_lookup (tags, "noreply", &arg))
+  if (!rc && mu_sieve_tag_lookup_untyped (mach, tags, "noreply", &arg))
     rc = mu_sieve_vlist_do (arg, regex_comparator, &rd);
   
   return rc;
@@ -341,24 +341,23 @@ check_db (mu_sieve_machine_t mach, mu_list_t tags, char *from)
 {
   mu_property_t prop;
   char *file;
-  mu_sieve_value_t *arg;
   unsigned int days;
   int rc;
   mu_stream_t str;
   mu_locker_t locker;
   const char *dbfile = "~/.vacation";
+  size_t n;
   
-  if (mu_sieve_tag_lookup (tags, "days", &arg))
+  if (mu_sieve_tag_lookup (mach, tags, "days", SVT_NUMBER, &n))
     {
-      days = arg->v.number;
+      days = n;
       if (days > DAYS_MAX)
 	days = DAYS_MAX;
     }
   else
     days = DAYS_DEFAULT;
 
-  if (mu_sieve_tag_lookup (tags, "database", &arg))
-    dbfile = arg->v.string;
+  mu_sieve_tag_lookup (mach, tags, "database", SVT_STRING, &dbfile);
   
   file = mu_tilde_expansion (dbfile, MU_HIERARCHY_DELIMITER, NULL);
   if (!file)
@@ -433,13 +432,9 @@ static void
 re_subject (mu_sieve_machine_t mach, mu_list_t tags, char **psubject)
 {
   char *subject;
-  mu_sieve_value_t *arg;
   char *prefix = "Re";
   
-  if (mu_sieve_tag_lookup (tags, "reply_prefix", &arg))
-    {
-      prefix = arg->v.string;
-    }
+  mu_sieve_tag_lookup (mach, tags, "reply_prefix", SVT_STRING, &prefix);
 
   subject = malloc (strlen (*psubject) + strlen (prefix) + 3);
   if (!subject)
@@ -467,20 +462,19 @@ static void
 vacation_subject (mu_sieve_machine_t mach, mu_list_t tags,
 		  mu_message_t msg, mu_header_t newhdr)
 {
-  mu_sieve_value_t *arg;
   char *value;
   char *subject;
   int subject_allocated = 0;
   mu_header_t hdr;
   
-  if (mu_sieve_tag_lookup (tags, "subject", &arg))
-    subject = arg->v.string;
+  if (mu_sieve_tag_lookup (mach, tags, "subject", SVT_STRING, &subject))
+    /* nothing */;
   else if (mu_message_get_header (msg, &hdr) == 0
 	   && mu_header_aget_value_unfold (hdr, MU_HEADER_SUBJECT,
 					   &value) == 0)
     {
       char *p;
-      
+
       int rc = mu_rfc2047_decode (MU_SIEVE_CHARSET, value, &p);
 
       subject_allocated = 1;
@@ -494,11 +488,11 @@ vacation_subject (mu_sieve_machine_t mach, mu_list_t tags,
 	  subject = p;
 	}
 
-      if (mu_sieve_tag_lookup (tags, "reply_regex", &arg))
+      if (mu_sieve_tag_lookup (mach, tags, "reply_regex", SVT_STRING, &p))
 	{
 	  char *err = NULL;
 	  
-	  rc = mu_unre_set_regex (arg->v.string, 0, &err);
+	  rc = mu_unre_set_regex (p, 0, &err);
 	  if (rc)
 	    {
 	      mu_sieve_error (mach,
@@ -619,7 +613,7 @@ vacation_reply (mu_sieve_machine_t mach, mu_list_t tags, mu_message_t msg,
   int rc;
   mu_sieve_value_t *val;
 
-  if (mu_sieve_tag_lookup (tags, "file", NULL))
+  if (mu_sieve_tag_lookup (mach, tags, "file", SVT_VOID, NULL))
     {
       mu_stream_t instr;
       
@@ -634,7 +628,7 @@ vacation_reply (mu_sieve_machine_t mach, mu_list_t tags, mu_message_t msg,
 	  return -1;
 	}
       
-      if (mu_sieve_tag_lookup (tags, "rfc2822", NULL))
+      if (mu_sieve_tag_lookup (mach, tags, "rfc2822", SVT_VOID, NULL))
 	{
 	  rc = mu_stream_to_message (instr, &newmsg);
 	  mu_stream_unref (instr);
@@ -722,7 +716,7 @@ vacation_reply (mu_sieve_machine_t mach, mu_list_t tags, mu_message_t msg,
     {
       mu_header_set_value (newhdr, MU_HEADER_TO, to, 0);
 
-      if (mu_sieve_tag_lookup (tags, "header", &val))
+      if (mu_sieve_tag_lookup_untyped (mach, tags, "header", &val))
 	{
 	  struct header_closure hc;
 	  hc.mach = mach;
@@ -774,7 +768,6 @@ sieve_action_vacation (mu_sieve_machine_t mach, mu_list_t args, mu_list_t tags)
   int rc;
   char *text, *from = NULL;
   char const *return_address;
-  mu_sieve_value_t *val;
   mu_message_t msg;
   mu_header_t hdr;
   char *my_address;
@@ -782,22 +775,15 @@ sieve_action_vacation (mu_sieve_machine_t mach, mu_list_t args, mu_list_t tags)
   if (diag (mach))
     return 0;
   
-  val = mu_sieve_value_get (args, 0);
-  if (!val)
-    {
-      mu_sieve_error (mach, _("cannot get text!"));
-      mu_sieve_abort (mach);
-    }
-  else
-    text = val->v.string;
+  mu_sieve_value_get (mach, args, 0, SVT_STRING, &text);
 
   msg = mu_sieve_get_message (mach);
   mu_message_get_header (msg, &hdr);
 
-  if (mu_sieve_tag_lookup (tags, "sender", &val))
+  if (mu_sieve_tag_lookup (mach, tags, "sender", SVT_STRING, &from))
     {
       /* Debugging hook: :sender sets fake reply address */
-      from = strdup (val->v.string);
+      from = strdup (from);
       if (!from)
         {
           mu_sieve_error (mach, "%lu: %s",
@@ -817,12 +803,12 @@ sieve_action_vacation (mu_sieve_machine_t mach, mu_list_t args, mu_list_t tags)
 
   my_address = mu_get_user_email (NULL);
 
-  if (mu_sieve_tag_lookup (tags, "always_reply", NULL))
+  if (mu_sieve_tag_lookup (mach, tags, "always_reply", SVT_VOID, NULL))
     return_address = my_address;
   else
     {
-      val = NULL;
-      mu_sieve_tag_lookup (tags, "aliases", &val);
+      mu_sieve_value_t *val = NULL;
+      mu_sieve_tag_lookup_untyped (mach, tags, "aliases", &val);
       if (match_addresses (hdr, my_address, val, &return_address) == 0)
 	{
 	  free (my_address);
@@ -839,8 +825,8 @@ sieve_action_vacation (mu_sieve_machine_t mach, mu_list_t args, mu_list_t tags)
       return 0;
     }
 
-  if (mu_sieve_tag_lookup (tags, "return_address", &val))
-    return_address = val->v.string;
+  mu_sieve_tag_lookup (mach, tags, "return_address", SVT_STRING,
+		       &return_address);
 
   rc = vacation_reply (mach, tags, msg, text, from, return_address);
   free (from);
diff --git a/libmu_sieve/relational.c b/libmu_sieve/relational.c
index 871d8e96b..19c9eec0e 100644
--- a/libmu_sieve/relational.c
+++ b/libmu_sieve/relational.c
@@ -83,12 +83,12 @@ mu_sieve_str_to_relcmp (const char *str,
 mu_sieve_relcmp_t
 mu_sieve_get_relcmp (mu_sieve_machine_t mach, mu_list_t tags)
 {
-  mu_sieve_value_t *arg;