diff --git a/Makefile.in b/Makefile.in
index cb92f876..44a7272d 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -93,7 +93,7 @@ subdir = .
 ACLOCAL_M4 = $(top_srcdir)/aclocal.m4
 am__aclocal_m4_deps = $(top_srcdir)/m4/ax_check_sign.m4 \
 	$(top_srcdir)/m4/ax_cxx_compile_stdcxx.m4 \
-	$(top_srcdir)/m4/ax_cxx_namespace.m4 \
+	$(top_srcdir)/m4/ax_cxx_namespaces.m4 \
 	$(top_srcdir)/m4/ax_lib_mysql.m4 $(top_srcdir)/m4/ax_numval.m4 \
 	$(top_srcdir)/m4/ax_pthread.m4 \
 	$(top_srcdir)/m4/hawk_try_cflags.m4 \
@@ -168,7 +168,7 @@ am__DIST_COMMON = $(srcdir)/Makefile.in $(top_srcdir)/ac/ar-lib \
 	$(top_srcdir)/ac/ltmain.sh $(top_srcdir)/ac/missing \
 	$(top_srcdir)/ac/tap-driver.sh $(top_srcdir)/pkgs/hawk.spec.in \
 	README.md ac/ar-lib ac/compile ac/config.guess ac/config.sub \
-	ac/depcomp ac/install-sh ac/ltmain.sh ac/missing
+	ac/install-sh ac/ltmain.sh ac/missing
 DISTFILES = $(DIST_COMMON) $(DIST_SOURCES) $(TEXINFOS) $(EXTRA_DIST)
 distdir = $(PACKAGE)-$(VERSION)
 top_distdir = $(distdir)
diff --git a/aclocal.m4 b/aclocal.m4
index 8cb6e58c..714d971d 100644
--- a/aclocal.m4
+++ b/aclocal.m4
@@ -1210,7 +1210,7 @@ AC_SUBST([am__untar])
 
 m4_include([m4/ax_check_sign.m4])
 m4_include([m4/ax_cxx_compile_stdcxx.m4])
-m4_include([m4/ax_cxx_namespace.m4])
+m4_include([m4/ax_cxx_namespaces.m4])
 m4_include([m4/ax_lib_mysql.m4])
 m4_include([m4/ax_numval.m4])
 m4_include([m4/ax_pthread.m4])
diff --git a/bin/Makefile.in b/bin/Makefile.in
index 37fb7b80..9473479f 100644
--- a/bin/Makefile.in
+++ b/bin/Makefile.in
@@ -93,7 +93,7 @@ subdir = bin
 ACLOCAL_M4 = $(top_srcdir)/aclocal.m4
 am__aclocal_m4_deps = $(top_srcdir)/m4/ax_check_sign.m4 \
 	$(top_srcdir)/m4/ax_cxx_compile_stdcxx.m4 \
-	$(top_srcdir)/m4/ax_cxx_namespace.m4 \
+	$(top_srcdir)/m4/ax_cxx_namespaces.m4 \
 	$(top_srcdir)/m4/ax_lib_mysql.m4 $(top_srcdir)/m4/ax_numval.m4 \
 	$(top_srcdir)/m4/ax_pthread.m4 \
 	$(top_srcdir)/m4/hawk_try_cflags.m4 \
diff --git a/configure b/configure
index ee8c828e..2bcd588c 100755
--- a/configure
+++ b/configure
@@ -1,6 +1,6 @@
 #! /bin/sh
 # Guess values for system-dependent variables and create Makefiles.
-# Generated by GNU Autoconf 2.71 for hawk 0.9.6.
+# Generated by GNU Autoconf 2.71 for hawk 0.9.7.
 #
 # Report bugs to <Chung, Hyung-Hwan (hyunghwan.chung@gmail.com)>.
 #
@@ -621,8 +621,8 @@ MAKEFLAGS=
 # Identity of this package.
 PACKAGE_NAME='hawk'
 PACKAGE_TARNAME='hawk'
-PACKAGE_VERSION='0.9.6'
-PACKAGE_STRING='hawk 0.9.6'
+PACKAGE_VERSION='0.9.7'
+PACKAGE_STRING='hawk 0.9.7'
 PACKAGE_BUGREPORT='Chung, Hyung-Hwan (hyunghwan.chung@gmail.com)'
 PACKAGE_URL='https://code.miflux.net/hyung-hwan/hawk'
 
@@ -1431,7 +1431,7 @@ if test "$ac_init_help" = "long"; then
   # Omit some internal or obsolete options to make the list less imposing.
   # This message is too long to be a string in the A/UX 3.1 sh.
   cat <<_ACEOF
-\`configure' configures hawk 0.9.6 to adapt to many kinds of systems.
+\`configure' configures hawk 0.9.7 to adapt to many kinds of systems.
 
 Usage: $0 [OPTION]... [VAR=VALUE]...
 
@@ -1502,7 +1502,7 @@ fi
 
 if test -n "$ac_init_help"; then
   case $ac_init_help in
-     short | recursive ) echo "Configuration of hawk 0.9.6:";;
+     short | recursive ) echo "Configuration of hawk 0.9.7:";;
    esac
   cat <<\_ACEOF
 
@@ -1641,7 +1641,7 @@ fi
 test -n "$ac_init_help" && exit $ac_status
 if $ac_init_version; then
   cat <<\_ACEOF
-hawk configure 0.9.6
+hawk configure 0.9.7
 generated by GNU Autoconf 2.71
 
 Copyright (C) 2021 Free Software Foundation, Inc.
@@ -2370,7 +2370,7 @@ cat >config.log <<_ACEOF
 This file contains any messages produced by compilers while
 running configure, to aid debugging if configure makes a mistake.
 
-It was created by hawk $as_me 0.9.6, which was
+It was created by hawk $as_me 0.9.7, which was
 generated by GNU Autoconf 2.71.  Invocation command line was
 
   $ $0$ac_configure_args_raw
@@ -3868,7 +3868,7 @@ fi
 
 # Define the identity of the package.
  PACKAGE='hawk'
- VERSION='0.9.6'
+ VERSION='0.9.7'
 
 
 printf "%s\n" "#define PACKAGE \"$PACKAGE\"" >>confdefs.h
@@ -25790,7 +25790,7 @@ else $as_nop
 fi
 
 test "${HAVE_CXX}" = "yes" || enable_cxx_is="no"
-test "${ax_cv_cxx_have_std_namespace}" = "yes" || enable_cxx_is="no"
+test "${ax_cv_cxx_namespaces}" = "yes" || enable_cxx_is="no"
 
  if test "${enable_cxx_is}" = "yes" ; then
   ENABLE_CXX_TRUE=
@@ -25966,7 +25966,7 @@ fi
 
 if test "x${enable_mod_mysql_is}" = "xauto" || test "x${enable_mod_mysql_is}" = "xyes"
 then
-	if ! test ${with_mysql+y}
+	if test ${with_mysql+y}
 	then
 		## as if --with-mysql is specified for AX_LIB_MYSQL below
 		with_mysql=yes
@@ -26939,7 +26939,7 @@ cat >>$CONFIG_STATUS <<\_ACEOF || ac_write_fail=1
 # report actual input values of CONFIG_FILES etc. instead of their
 # values after options handling.
 ac_log="
-This file was extended by hawk $as_me 0.9.6, which was
+This file was extended by hawk $as_me 0.9.7, which was
 generated by GNU Autoconf 2.71.  Invocation command line was
 
   CONFIG_FILES    = $CONFIG_FILES
@@ -27008,7 +27008,7 @@ ac_cs_config_escaped=`printf "%s\n" "$ac_cs_config" | sed "s/^ //; s/'/'\\\\\\\\
 cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
 ac_cs_config='$ac_cs_config_escaped'
 ac_cs_version="\\
-hawk config.status 0.9.6
+hawk config.status 0.9.7
 configured by $0, generated by GNU Autoconf 2.71,
   with options \\"\$ac_cs_config\\"
 
diff --git a/configure.ac b/configure.ac
index 0a99cdb5..78eeddec 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1,6 +1,6 @@
 dnl AC_PREREQ([2.71])
 
-AC_INIT([hawk],[0.9.6],[Chung, Hyung-Hwan (hyunghwan.chung@gmail.com)],[],[https://code.miflux.net/hyung-hwan/hawk])
+AC_INIT([hawk],[0.9.7],[Chung, Hyung-Hwan (hyunghwan.chung@gmail.com)],[],[https://code.miflux.net/hyung-hwan/hawk])
 
 AC_CONFIG_HEADERS([lib/hawk-cfg.h])
 AC_CONFIG_AUX_DIR([ac])
@@ -889,7 +889,7 @@ AC_ARG_ENABLE([cxx],
 dnl disable c++ if no c++ compiler was found
 test "${HAVE_CXX}" = "yes" || enable_cxx_is="no"
 dnl disable c++ if the compiler is too old.
-test "${ax_cv_cxx_have_std_namespace}" = "yes" || enable_cxx_is="no"
+test "${ax_cv_cxx_namespaces}" = "yes" || enable_cxx_is="no"
 
 AM_CONDITIONAL(ENABLE_CXX, test "${enable_cxx_is}" = "yes" )
 
diff --git a/lib/Hawk.hpp b/lib/Hawk.hpp
index 4b67219d..e078d520 100644
--- a/lib/Hawk.hpp
+++ b/lib/Hawk.hpp
@@ -1046,6 +1046,7 @@ public:
 		}
 
 		int getType () const { return hawk_get_val_type(this->val); }
+		const hawk_ooch_t* getTypeName () const { return hawk_get_val_type_name(this->val); }
 
 		int getInt (hawk_int_t* v) const;
 		int getFlt (hawk_flt_t* v) const;
diff --git a/lib/Makefile.in b/lib/Makefile.in
index ccdf6ddb..fabed46a 100644
--- a/lib/Makefile.in
+++ b/lib/Makefile.in
@@ -120,7 +120,7 @@ subdir = lib
 ACLOCAL_M4 = $(top_srcdir)/aclocal.m4
 am__aclocal_m4_deps = $(top_srcdir)/m4/ax_check_sign.m4 \
 	$(top_srcdir)/m4/ax_cxx_compile_stdcxx.m4 \
-	$(top_srcdir)/m4/ax_cxx_namespace.m4 \
+	$(top_srcdir)/m4/ax_cxx_namespaces.m4 \
 	$(top_srcdir)/m4/ax_lib_mysql.m4 $(top_srcdir)/m4/ax_numval.m4 \
 	$(top_srcdir)/m4/ax_pthread.m4 \
 	$(top_srcdir)/m4/hawk_try_cflags.m4 \
diff --git a/lib/hawk.h b/lib/hawk.h
index 02e50b5e..c44b27ef 100644
--- a/lib/hawk.h
+++ b/lib/hawk.h
@@ -3663,6 +3663,10 @@ HAWK_EXPORT int hawk_get_val_type (
 	hawk_val_t* val
 );
 
+HAWK_EXPORT const hawk_ooch_t* hawk_get_val_type_name (
+	hawk_val_t* val
+);
+
 #if defined(__cplusplus)
 }
 #endif
diff --git a/lib/val.c b/lib/val.c
index 7a11dd9a..3893d5df 100644
--- a/lib/val.c
+++ b/lib/val.c
@@ -27,13 +27,32 @@
 #define CHUNKSIZE HAWK_VAL_CHUNK_SIZE
 
 static hawk_val_nil_t hawk_nil = { HAWK_VAL_NIL, 0, 1, 0, 0 };
+/* zero-length string */
 static hawk_val_str_t hawk_zls = { HAWK_VAL_STR, 0, 1, 0, 0, { HAWK_T(""), 0 } };
+/* zero-length byte string */
 static hawk_val_mbs_t hawk_zlbs = { HAWK_VAL_MBS, 0, 1, 0, 0, { HAWK_BT(""), 0 } };
 
 hawk_val_t* hawk_val_nil = (hawk_val_t*)&hawk_nil;
 hawk_val_t* hawk_val_zls = (hawk_val_t*)&hawk_zls; 
 hawk_val_t* hawk_val_zlbs = (hawk_val_t*)&hawk_zlbs;
 
+static const hawk_ooch_t* val_type_name[] =
+{
+	/* synchronize this table with enum hawk_val_type_t in hawk.h */
+	HAWK_T("nil"),
+	HAWK_T("char"),
+	HAWK_T("bchar"),
+	HAWK_T("int"),
+	HAWK_T("flt"),
+	HAWK_T("str"),
+	HAWK_T("mbs"),
+	HAWK_T("fun"),
+	HAWK_T("map"),
+	HAWK_T("array"),
+
+	HAWK_T("rex"),
+	HAWK_T("ref")
+};
 
 /* --------------------------------------------------------------------- */
 
@@ -472,6 +491,11 @@ int hawk_get_val_type (hawk_val_t* val)
 	return HAWK_GET_VAL_TYPE(val);
 }
 
+const hawk_ooch_t* hawk_get_val_type_name (hawk_val_t* val)
+{
+	return val_type_name[HAWK_GET_VAL_TYPE(val)];
+}
+
 hawk_val_t* hawk_get_nil_val (void)
 {
 	return (hawk_val_t*)&hawk_nil;
@@ -1431,25 +1455,7 @@ int hawk_rtx_getvaltype (hawk_rtx_t* rtx, const hawk_val_t* val)
 
 const hawk_ooch_t* hawk_rtx_getvaltypename(hawk_rtx_t* rtx, const hawk_val_t* val)
 {
-	static const hawk_ooch_t* __val_type_name[] =
-	{
-		/* synchronize this table with enum hawk_val_type_t in hawk.h */
-		HAWK_T("nil"),
-		HAWK_T("char"),
-		HAWK_T("bchar"),
-		HAWK_T("int"),
-		HAWK_T("flt"),
-		HAWK_T("str"),
-		HAWK_T("mbs"),
-		HAWK_T("fun"),
-		HAWK_T("map"),
-		HAWK_T("array"),
-
-		HAWK_T("rex"),
-		HAWK_T("ref")
-	};
-
-	return __val_type_name[HAWK_RTX_GETVALTYPE(rtx, val)];
+	return val_type_name[HAWK_RTX_GETVALTYPE(rtx, val)];
 }
 
 int hawk_rtx_getintfromval (hawk_rtx_t* rtx, const hawk_val_t* val)
diff --git a/m4/ax_cxx_namespace.m4 b/m4/ax_cxx_namespaces.m4
similarity index 100%
rename from m4/ax_cxx_namespace.m4
rename to m4/ax_cxx_namespaces.m4
diff --git a/mod/Makefile.in b/mod/Makefile.in
index d3b2db3a..ca9c11ae 100644
--- a/mod/Makefile.in
+++ b/mod/Makefile.in
@@ -100,7 +100,7 @@ subdir = mod
 ACLOCAL_M4 = $(top_srcdir)/aclocal.m4
 am__aclocal_m4_deps = $(top_srcdir)/m4/ax_check_sign.m4 \
 	$(top_srcdir)/m4/ax_cxx_compile_stdcxx.m4 \
-	$(top_srcdir)/m4/ax_cxx_namespace.m4 \
+	$(top_srcdir)/m4/ax_cxx_namespaces.m4 \
 	$(top_srcdir)/m4/ax_lib_mysql.m4 $(top_srcdir)/m4/ax_numval.m4 \
 	$(top_srcdir)/m4/ax_pthread.m4 \
 	$(top_srcdir)/m4/hawk_try_cflags.m4 \
diff --git a/samples/Makefile.in b/samples/Makefile.in
index ed481e56..ae419ed8 100644
--- a/samples/Makefile.in
+++ b/samples/Makefile.in
@@ -94,7 +94,7 @@ subdir = samples
 ACLOCAL_M4 = $(top_srcdir)/aclocal.m4
 am__aclocal_m4_deps = $(top_srcdir)/m4/ax_check_sign.m4 \
 	$(top_srcdir)/m4/ax_cxx_compile_stdcxx.m4 \
-	$(top_srcdir)/m4/ax_cxx_namespace.m4 \
+	$(top_srcdir)/m4/ax_cxx_namespaces.m4 \
 	$(top_srcdir)/m4/ax_lib_mysql.m4 $(top_srcdir)/m4/ax_numval.m4 \
 	$(top_srcdir)/m4/ax_pthread.m4 \
 	$(top_srcdir)/m4/hawk_try_cflags.m4 \
diff --git a/t/Makefile.in b/t/Makefile.in
index 667f64ad..9f7c7d0c 100644
--- a/t/Makefile.in
+++ b/t/Makefile.in
@@ -93,7 +93,7 @@ subdir = t
 ACLOCAL_M4 = $(top_srcdir)/aclocal.m4
 am__aclocal_m4_deps = $(top_srcdir)/m4/ax_check_sign.m4 \
 	$(top_srcdir)/m4/ax_cxx_compile_stdcxx.m4 \
-	$(top_srcdir)/m4/ax_cxx_namespace.m4 \
+	$(top_srcdir)/m4/ax_cxx_namespaces.m4 \
 	$(top_srcdir)/m4/ax_lib_mysql.m4 $(top_srcdir)/m4/ax_numval.m4 \
 	$(top_srcdir)/m4/ax_pthread.m4 \
 	$(top_srcdir)/m4/hawk_try_cflags.m4 \
diff --git a/tools/Makefile.in b/tools/Makefile.in
index 0935fce7..886fc493 100644
--- a/tools/Makefile.in
+++ b/tools/Makefile.in
@@ -93,7 +93,7 @@ subdir = tools
 ACLOCAL_M4 = $(top_srcdir)/aclocal.m4
 am__aclocal_m4_deps = $(top_srcdir)/m4/ax_check_sign.m4 \
 	$(top_srcdir)/m4/ax_cxx_compile_stdcxx.m4 \
-	$(top_srcdir)/m4/ax_cxx_namespace.m4 \
+	$(top_srcdir)/m4/ax_cxx_namespaces.m4 \
 	$(top_srcdir)/m4/ax_lib_mysql.m4 $(top_srcdir)/m4/ax_numval.m4 \
 	$(top_srcdir)/m4/ax_pthread.m4 \
 	$(top_srcdir)/m4/hawk_try_cflags.m4 \