diff --git a/qse/configure b/qse/configure
index a04bc4ea..1f00015a 100755
--- a/qse/configure
+++ b/qse/configure
@@ -1,6 +1,6 @@
 #! /bin/sh
 # Guess values for system-dependent variables and create Makefiles.
-# Generated by GNU Autoconf 2.63 for qse 0.5.1.
+# Generated by GNU Autoconf 2.63 for qse 0.5.2.
 #
 # Report bugs to <bacon@abiyo.net>.
 #
@@ -745,8 +745,8 @@ SHELL=${CONFIG_SHELL-/bin/sh}
 # Identity of this package.
 PACKAGE_NAME='qse'
 PACKAGE_TARNAME='qse'
-PACKAGE_VERSION='0.5.1'
-PACKAGE_STRING='qse 0.5.1'
+PACKAGE_VERSION='0.5.2'
+PACKAGE_STRING='qse 0.5.2'
 PACKAGE_BUGREPORT='bacon@abiyo.net'
 
 # Factoring default headers for most tests.
@@ -1511,7 +1511,7 @@ 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 qse 0.5.1 to adapt to many kinds of systems.
+\`configure' configures qse 0.5.2 to adapt to many kinds of systems.
 
 Usage: $0 [OPTION]... [VAR=VALUE]...
 
@@ -1581,7 +1581,7 @@ fi
 
 if test -n "$ac_init_help"; then
   case $ac_init_help in
-     short | recursive ) echo "Configuration of qse 0.5.1:";;
+     short | recursive ) echo "Configuration of qse 0.5.2:";;
    esac
   cat <<\_ACEOF
 
@@ -1695,7 +1695,7 @@ fi
 test -n "$ac_init_help" && exit $ac_status
 if $ac_init_version; then
   cat <<\_ACEOF
-qse configure 0.5.1
+qse configure 0.5.2
 generated by GNU Autoconf 2.63
 
 Copyright (C) 1992, 1993, 1994, 1995, 1996, 1998, 1999, 2000, 2001,
@@ -1709,7 +1709,7 @@ 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 qse $as_me 0.5.1, which was
+It was created by qse $as_me 0.5.2, which was
 generated by GNU Autoconf 2.63.  Invocation command line was
 
   $ $0 $@
@@ -2436,7 +2436,7 @@ fi
 
 # Define the identity of the package.
  PACKAGE='qse'
- VERSION='0.5.1'
+ VERSION='0.5.2'
 
 
 cat >>confdefs.h <<_ACEOF
@@ -26126,7 +26126,7 @@ exec 6>&1
 # report actual input values of CONFIG_FILES etc. instead of their
 # values after options handling.
 ac_log="
-This file was extended by qse $as_me 0.5.1, which was
+This file was extended by qse $as_me 0.5.2, which was
 generated by GNU Autoconf 2.63.  Invocation command line was
 
   CONFIG_FILES    = $CONFIG_FILES
@@ -26189,7 +26189,7 @@ Report bugs to <bug-autoconf@gnu.org>."
 _ACEOF
 cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
 ac_cs_version="\\
-qse config.status 0.5.1
+qse config.status 0.5.2
 configured by $0, generated by GNU Autoconf 2.63,
   with options \\"`$as_echo "$ac_configure_args" | sed 's/^ //; s/[\\""\`\$]/\\\\&/g'`\\"
 
diff --git a/qse/configure.ac b/qse/configure.ac
index 061c316c..781d8138 100644
--- a/qse/configure.ac
+++ b/qse/configure.ac
@@ -1,5 +1,5 @@
 dnl AC_PREREQ(2.59)
-AC_INIT([qse],[0.5.1],[bacon@abiyo.net])
+AC_INIT([qse],[0.5.2],[bacon@abiyo.net])
 AC_CONFIG_HEADER([include/qse/config.h])
 AC_CONFIG_AUX_DIR([ac/au])
 AC_CONFIG_MACRO_DIR([ac/m4])
diff --git a/qse/include/qse/awk/Awk.hpp b/qse/include/qse/awk/Awk.hpp
index 474d14fe..67e355bd 100644
--- a/qse/include/qse/awk/Awk.hpp
+++ b/qse/include/qse/awk/Awk.hpp
@@ -1,5 +1,5 @@
 /*
- * $Id: Awk.hpp 228 2009-07-11 03:01:36Z hyunghwan.chung $
+ * $Id: Awk.hpp 229 2009-07-12 13:06:01Z hyunghwan.chung $
  *
    Copyright 2006-2009 Chung, Hyung-Hwan.
 
@@ -55,6 +55,9 @@ public:
 
 	typedef qse_awk_rio_cmd_t rio_cmd_t;
 
+	class Run;
+	friend class Run;
+
 	class Source
 	{
 	public:
@@ -118,10 +121,10 @@ public:
 		Source& operator= (const Source&);
 	};
 
-	class Run;
-
 	/**
-	 * RIO class 
+	 * The RIOBase class is a base class to represent runtime I/O context.
+	 * The Console, File, Pipe classes inherit this class to implement
+	 * an actual I/O context.
 	 */
 	class RIOBase
 	{
@@ -219,74 +222,116 @@ public:
 		char_t* filename;
 	};
 
-	class Argument;
-	class Return;
-
-	friend class Run;
-	friend class Argument;
-	friend class Return;
-
 	class Value
 	{
 	public:
-		Value (): run (QSE_NULL), val (qse_awk_val_nil) {}
-		Value (Run& run): run (&run), val (qse_awk_val_nil) {}
-		Value (Run* run): run (run), val (qse_awk_val_nil) {}
+		// initialization
+		void* operator new (size_t n, Run* run) throw ();
+		void* operator new[] (size_t n, Run* run) throw ();
+
+	#if !defined(__BORLANDC__) 
+		// deletion when initialization fails
+		void operator delete (void* p, Run* run) throw ();
+		void operator delete[] (void* p, Run* run) throw ();
+	#endif
+
+		// normal deletion
+		void operator delete (void* p) throw ();
+		void operator delete[] (void* p) throw ();
+
+		Value ();
+		Value (Run& run);
+		Value (Run* run);
 
 		Value (const Value& v);
 		~Value ();
 
 		Value& operator= (const Value& v);
 
+		void clear ();
+
 		operator val_t* () const { return val; }
 		operator long_t () const;
 		operator real_t () const;
 		operator const char_t* () const;
 
-		void clear ();
+		val_t* toVal () const
+		{
+			return operator val_t* ();
+		}
 
-		int get (long_t* v) const;
-		int get (real_t* v) const;
-		int get (const char_t** str, size_t* len) const;
+		long_t toInt () const
+		{
+			return operator long_t ();
+		}
 
-		int set (val_t* v);
-		int set (Run* r, val_t* v);
+		real_t toReal () const
+		{
+			return operator real_t ();
+		}
 
-		int set (long_t v);
-		int set (Run* r, long_t v);
-		int set (real_t v);
-		int set (Run* r, real_t v);
-		int set (const char_t* str, size_t len);
-		int set (Run* r, const char_t* str, size_t len);
-		int set (const char_t* str);
-		int set (Run* r, const char_t* str);
+		const char_t* toStr (size_t* len) const
+		{
+			const char_t* p;
+			size_t l;
 
-		int setIndexed (const char_t* idx, size_t isz, val_t* v);
-		int setIndexed (Run* r, const char_t* idx, size_t isz, val_t* v);
+			if (getStr (&p, &l) == -1) 
+			{
+				p = EMPTY_STRING;
+				l = 0;
+			}
+			
+			if (len != QSE_NULL) *len = l;
+			return p;
+		}
 
-		int setIndexed (const char_t* idx, size_t isz, long_t v);
-		int setIndexed (Run* r, const char_t* idx, size_t isz, long_t v);
-		int setIndexed (
+		int getInt (long_t* v) const;
+		int getReal (real_t* v) const;
+		int getStr (const char_t** str, size_t* len) const;
+
+		int setVal (val_t* v);
+		int setVal (Run* r, val_t* v);
+
+		int setInt (long_t v);
+		int setInt (Run* r, long_t v);
+		int setReal (real_t v);
+		int setReal (Run* r, real_t v);
+		int setStr (const char_t* str, size_t len);
+		int setStr (Run* r, const char_t* str, size_t len);
+		int setStr (const char_t* str);
+		int setStr (Run* r, const char_t* str);
+
+		int setIndexedVal (
+			const char_t* idx, size_t isz, val_t* v);
+		int setIndexedVal (
+			Run* r, const char_t* idx, size_t isz, val_t* v);
+
+		int setIndexedInt (
+			const char_t* idx, size_t isz, long_t v);
+		int setIndexedInt (
+			Run* r, const char_t* idx, size_t isz, long_t v);
+
+		int setIndexedReal (
 			const char_t* idx,
 			size_t        isz,
 			real_t        v
 		);
 
-		int setIndexed (
+		int setIndexedReal (
 			Run*          r,
 			const char_t* idx,
 			size_t        isz,
 			real_t        v
 		);
 
-		int setIndexed (
+		int setIndexedStr (
 			const char_t* idx,
 			size_t        isz,
 			const char_t* str,
 			size_t        len
 		);
 
-		int setIndexed (
+		int setIndexedStr (
 			Run*          r,
 			const char_t* idx,
 			size_t        isz,
@@ -294,6 +339,19 @@ public:
 			size_t        len
 		);
 
+		int setIndexedStr (
+			const char_t* idx,
+			size_t        isz,
+			const char_t* str
+		);
+
+		int setIndexedStr (
+			Run*          r,
+			const char_t* idx,
+			size_t        isz,
+			const char_t* str
+		);
+
 		bool isIndexed () const;
 
 		int getIndexed (
@@ -305,111 +363,13 @@ public:
 	protected:
 		Run* run;
 		val_t* val;
-	};
 
-	/**
-	 * Represents an argument to an intrinsic function
-	 */
-	class Argument
-	{
-	public:
-		friend class Awk;
-		friend class Run;
+		mutable struct
+		{	
+			qse_xstr_t str;
+		} cached;
 
-		Argument (Run& run);
-		Argument (Run* run);
-		~Argument ();
-
-	protected:
-		Argument ();
-		void clear ();
-
-	public:
-		// initialization
-		void* operator new (size_t n, awk_t* awk) throw ();
-		void* operator new[] (size_t n, awk_t* awk) throw ();
-
-	#if !defined(__BORLANDC__) 
-		// deletion when initialization fails
-		void operator delete (void* p, awk_t* awk);
-		void operator delete[] (void* p, awk_t* awk);
-	#endif
-
-		// normal deletion
-		void operator delete (void* p);
-		void operator delete[] (void* p);
-
-	private:
-		Argument (const Argument&);
-		Argument& operator= (const Argument&);
-
-	protected:
-		int init (val_t* v);
-		int init (const char_t* str, size_t len);
-
-	public:
-		long_t toInt () const;
-		real_t toReal () const;
-		const char_t* toStr (size_t* len) const;
-
-		bool isIndexed () const;
-
-		int getIndexed (const char_t* idxptr, Argument& val) const;
-		int getIndexed (const char_t* idxptr, size_t idxlen, Argument& val) const;
-		int getIndexed (long_t idx, Argument& val) const;
-
-		int getFirstIndex (Argument& val) const;
-		int getNextIndex (Argument& val) const;
-
-	protected:
-		Run* run;
-		val_t* val;
-
-		qse_long_t inum;
-		qse_real_t rnum;
-		mutable qse_str_t str;
-	};
-
-	/**
-	 * Represents a return value of an intrinsic function
-	 */
-	class Return
-	{
-	public:
-		friend class Awk;
-		friend class Run;
-
-		Return (Run& run);
-		Return (Run* run);
-		~Return ();
-
-	private:
-		Return (const Return&);
-		Return& operator= (const Return&);
-
-	protected:
-		val_t* toVal () const;
-		operator val_t* () const;
-
-	public:
-		int set (long_t v);
-		int set (real_t v); 
-		int set (const char_t* ptr, size_t len);
-
-		bool isIndexed () const;
-
-		int setIndexed (const char_t* idx, size_t iln, long_t v);
-		int setIndexed (const char_t* idx, size_t iln, real_t v);
-		int setIndexed (const char_t* idx, size_t iln, const char_t* str, size_t sln);
-		int setIndexed (long_t idx, long_t v);
-		int setIndexed (long_t idx, real_t v);
-		int setIndexed (long_t idx, const char_t* str, size_t sln);
-
-		void clear ();
-
-	protected:
-		Run* run;
-		val_t* val;
+		static const char_t* EMPTY_STRING;
 	};
 
 	// generated by generrcode.awk
@@ -608,9 +568,7 @@ public:
 	{
 	protected:
 		friend class Awk;
-		friend class Argument;
-		friend class Return;
-		friend class RIO;
+		friend class Value;
 
 		Run (Awk* awk);
 		Run (Awk* awk, rtx_t* run);
@@ -702,7 +660,7 @@ public:
 		 *  	On success, 0 is returned.
 		 *  	On failure, -1 is returned.
 		 */
-		int setGlobal (int id, const Return& global);
+		int setGlobal (int id, const Value& global);
 
 		/**
 		 * Gets the value of a global variable.
@@ -720,7 +678,7 @@ public:
 		 * 	On success, 0 is returned.
 		 * 	On failure, -1 is returned.
 		 */
-		int getGlobal (int id, Argument& global) const;
+		int getGlobal (int id, Value& global) const;
 
 		void* alloc (size_t size);
 		void free (void* ptr);
@@ -847,8 +805,9 @@ public:
 	 */
 	virtual int call (
 		const char_t* name,
-		const Return* args,
-		size_t nargs
+		Value*        ret,
+		const Value*  args,
+		size_t        nargs
 	);
 
 	/**
@@ -887,7 +846,7 @@ public:
 	 * Represents a user-defined intrinsic function.
 	 */
 	typedef int (Awk::*FunctionHandler) (
-		Run& run, Return& ret, const Argument* args, size_t nargs, 
+		Run& run, Value& ret, const Value* args, size_t nargs, 
 		const char_t* name, size_t len);
 
 	/**
@@ -953,7 +912,7 @@ protected:
 
 	// run-time callbacks
 	virtual bool onLoopEnter (Run& run);
-	virtual void onLoopExit (Run& run, const Argument& ret);
+	virtual void onLoopExit (Run& run, const Value& ret);
 	virtual void onStatement (Run& run, size_t line);
 	
 	// primitive handlers 
diff --git a/qse/include/qse/awk/StdAwk.hpp b/qse/include/qse/awk/StdAwk.hpp
index 04f0a4f3..c6fa99ed 100644
--- a/qse/include/qse/awk/StdAwk.hpp
+++ b/qse/include/qse/awk/StdAwk.hpp
@@ -1,5 +1,5 @@
 /*
- * $Id: StdAwk.hpp 226 2009-07-09 12:46:14Z hyunghwan.chung $
+ * $Id: StdAwk.hpp 229 2009-07-12 13:06:01Z hyunghwan.chung $
  *
    Copyright 2006-2009 Chung, Hyung-Hwan.
 
@@ -78,29 +78,29 @@ public:
 
 protected:
 	// intrinsic functions 
-	int sin (Run& run, Return& ret, const Argument* args, size_t nargs, 
+	int sin (Run& run, Value& ret, const Value* args, size_t nargs, 
 		const char_t* name, size_t len);
-	int cos (Run& run, Return& ret, const Argument* args, size_t nargs, 
+	int cos (Run& run, Value& ret, const Value* args, size_t nargs, 
 		const char_t* name, size_t len);
-	int tan (Run& run, Return& ret, const Argument* args, size_t nargs, 
+	int tan (Run& run, Value& ret, const Value* args, size_t nargs, 
 		const char_t* name, size_t len);
-	int atan (Run& run, Return& ret, const Argument* args, size_t nargs,
+	int atan (Run& run, Value& ret, const Value* args, size_t nargs,
 		const char_t* name, size_t len);
-	int atan2 (Run& run, Return& ret, const Argument* args, size_t nargs,
+	int atan2 (Run& run, Value& ret, const Value* args, size_t nargs,
 		const char_t* name, size_t len);
-	int log (Run& run, Return& ret, const Argument* args, size_t nargs,
+	int log (Run& run, Value& ret, const Value* args, size_t nargs,
 		const char_t* name, size_t len);
-	int exp (Run& run, Return& ret, const Argument* args, size_t nargs,
+	int exp (Run& run, Value& ret, const Value* args, size_t nargs,
 		const char_t* name, size_t len);
-	int sqrt (Run& run, Return& ret, const Argument* args, size_t nargs,
+	int sqrt (Run& run, Value& ret, const Value* args, size_t nargs,
 		const char_t* name, size_t len);
-	int fnint (Run& run, Return& ret, const Argument* args, size_t nargs,
+	int fnint (Run& run, Value& ret, const Value* args, size_t nargs,
 		const char_t* name, size_t len);
-	int rand (Run& run, Return& ret, const Argument* args, size_t nargs,
+	int rand (Run& run, Value& ret, const Value* args, size_t nargs,
 		const char_t* name, size_t len);
-	int srand (Run& run, Return& ret, const Argument* args, size_t nargs,
+	int srand (Run& run, Value& ret, const Value* args, size_t nargs,
 		const char_t* name, size_t len);
-	int system (Run& run, Return& ret, const Argument* args, size_t nargs,
+	int system (Run& run, Value& ret, const Value* args, size_t nargs,
 		const char_t* name, size_t len);
 
 	// pipe io handlers 
diff --git a/qse/lib/awk/Awk.cpp b/qse/lib/awk/Awk.cpp
index cb4f29e0..8610a27e 100644
--- a/qse/lib/awk/Awk.cpp
+++ b/qse/lib/awk/Awk.cpp
@@ -1,5 +1,5 @@
 /*
- * $Id: Awk.cpp 228 2009-07-11 03:01:36Z hyunghwan.chung $
+ * $Id: Awk.cpp 229 2009-07-12 13:06:01Z hyunghwan.chung $
  *
    Copyright 2006-2009 Chung, Hyung-Hwan.
 
@@ -169,22 +169,101 @@ Awk::Console::Mode Awk::Console::getMode () const
 // Awk::Value
 //////////////////////////////////////////////////////////////////
 
+const Awk::char_t* Awk::Value::EMPTY_STRING = QSE_T("");
+
+void* Awk::Value::operator new (size_t n, Run* run) throw ()
+{
+	void* ptr = qse_awk_rtx_alloc (run->rtx, QSE_SIZEOF(run) + n);
+	if (ptr == QSE_NULL) return QSE_NULL;
+
+	*(Run**)ptr = run;
+	return (char*)ptr+QSE_SIZEOF(run);
+}
+
+void* Awk::Value::operator new[] (size_t n, Run* run) throw ()
+{
+	void* ptr = qse_awk_rtx_alloc (run->rtx, QSE_SIZEOF(run) + n);
+	if (ptr == QSE_NULL) return QSE_NULL;
+
+	*(Run**)ptr = run;
+	return (char*)ptr+QSE_SIZEOF(run);
+}
+
+#if !defined(__BORLANDC__)
+void Awk::Value::operator delete (void* ptr, Run* run) throw ()
+{
+	qse_awk_rtx_free (run->rtx, (char*)ptr-QSE_SIZEOF(run));
+}
+
+void Awk::Value::operator delete[] (void* ptr, Run* run) throw ()
+{
+	qse_awk_rtx_free (run->rtx, (char*)ptr-QSE_SIZEOF(run));
+}
+#endif
+
+void Awk::Value::operator delete (void* ptr) throw ()
+{
+	void* p = (char*)ptr-QSE_SIZEOF(Run*);
+	qse_awk_rtx_free ((*(Run**)p)->rtx, p);
+}
+
+void Awk::Value::operator delete[] (void* ptr) throw ()
+{
+	void* p = (char*)ptr-QSE_SIZEOF(Run*);
+	qse_awk_rtx_free ((*(Run**)p)->rtx, p);
+}
+
+Awk::Value::Value (): run (QSE_NULL), val (qse_awk_val_nil) 
+{
+	cached.str.ptr = QSE_NULL;
+	cached.str.len = 0;
+}
+
+Awk::Value::Value (Run& run): run (&run), val (qse_awk_val_nil) 
+{
+	cached.str.ptr = QSE_NULL;
+	cached.str.len = 0;
+}
+
+Awk::Value::Value (Run* run): run (run), val (qse_awk_val_nil) 
+{
+	cached.str.ptr = QSE_NULL;
+	cached.str.len = 0;
+}
+
 Awk::Value::Value (const Value& v): run (v.run), val (v.val)
 {
 	if (run != QSE_NULL)
 		qse_awk_rtx_refupval (run->rtx, val);
+
+	cached.str.ptr = QSE_NULL;
+	cached.str.len = 0;
 }
 
 Awk::Value::~Value ()
 {
 	if (run != QSE_NULL)
+	{
 		qse_awk_rtx_refdownval (run->rtx, val);
+		if (cached.str.ptr != QSE_NULL)
+			qse_awk_rtx_free (run->rtx, cached.str.ptr);
+	}
 }
 
 Awk::Value& Awk::Value::operator= (const Value& v)
 {
+	if (this == &v) return *this;
+
 	if (run != QSE_NULL)
+	{
 		qse_awk_rtx_refdownval (run->rtx, val);
+		if (cached.str.ptr != QSE_NULL)
+		{
+			qse_awk_rtx_free (run->rtx, cached.str.ptr);
+			cached.str.ptr = QSE_NULL;
+			cached.str.len = 0;
+		}
+	}
 
 	run = v.run;
 	val = v.val;
@@ -201,6 +280,13 @@ void Awk::Value::clear ()
 	{
 		qse_awk_rtx_refdownval (run->rtx, val);
 
+		if (cached.str.ptr != QSE_NULL)
+		{
+			qse_awk_rtx_free (run->rtx, cached.str.ptr);
+			cached.str.ptr = QSE_NULL;
+			cached.str.len = 0;
+		}
+
 		run = QSE_NULL;
 		val = qse_awk_val_nil;
 	}
@@ -209,14 +295,14 @@ void Awk::Value::clear ()
 Awk::Value::operator Awk::long_t () const
 {
 	long_t v;
-	if (get (&v) <= -1) v = 0;
+	if (getInt (&v) <= -1) v = 0;
 	return v;
 }
 
 Awk::Value::operator Awk::real_t () const
 {
 	real_t v;
-	if (get (&v) <= -1) v = 0.0;
+	if (getReal (&v) <= -1) v = 0.0;
 	return v;
 }
 
@@ -224,15 +310,19 @@ Awk::Value::operator const Awk::char_t* () const
 {
 	const char_t* ptr;
 	size_t len;
-	if (get (&ptr, &len) <= -1) ptr = QSE_T("");
+	if (getStr (&ptr, &len) <= -1) ptr = QSE_T("");
 	return ptr;
 }
 
-int Awk::Value::get (long_t* v) const
+int Awk::Value::getInt (long_t* v) const
 {
 	long_t lv = 0;
 
-	if (run != QSE_NULL)
+	QSE_ASSERT (val != QSE_NULL);
+
+	if (run != QSE_NULL && 
+	    val->type != QSE_AWK_VAL_NIL &&
+	    val->type != QSE_AWK_VAL_MAP)
 	{
 		real_t rv;
 		int n = qse_awk_rtx_valtonum (run->rtx, val, &lv, &rv);
@@ -244,11 +334,15 @@ int Awk::Value::get (long_t* v) const
 	return 0;
 }
 
-int Awk::Value::get (real_t* v) const
+int Awk::Value::getReal (real_t* v) const
 {
 	real_t rv = 0;
 
-	if (run != QSE_NULL)
+	QSE_ASSERT (val != QSE_NULL);
+
+	if (run != QSE_NULL && 
+	    val->type != QSE_AWK_VAL_NIL &&
+	    val->type != QSE_AWK_VAL_MAP)
 	{
 		long_t lv;
 		int n = qse_awk_rtx_valtonum (run->rtx, val, &lv, &rv);
@@ -260,37 +354,74 @@ int Awk::Value::get (real_t* v) const
 	return 0;
 }
 
-int Awk::Value::get (const char_t** str, size_t* len) const
+int Awk::Value::getStr (const char_t** str, size_t* len) const
 {
-#if 0
-if v is a string, return the pointer and the length.
-otherwise call valtostr.... how can i handle free then???
+	const char_t* p = EMPTY_STRING;
+	size_t l = 0;
 
-	real_t rv = 0;
+	QSE_ASSERT (val != QSE_NULL);
 
-	if (run != QSE_NULL)
+	if (run != QSE_NULL && 
+	    val->type != QSE_AWK_VAL_NIL &&
+	    val->type != QSE_AWK_VAL_MAP)
 	{
-		long_t lv;
-		int n = qse_awk_rtx_valtostr (run->rtx, val, &lv, &rv);
-		if (n <= -1) return -1;
-		if (n == 0) rv = lv;
+		if (val->type == QSE_AWK_VAL_STR)
+		{
+			p = ((qse_awk_val_str_t*)val)->ptr;
+			l = ((qse_awk_val_str_t*)val)->len;
+		}
+		else
+		{
+			if (cached.str.ptr == QSE_NULL)
+			{
+				qse_awk_rtx_valtostr_out_t out;
+				out.type = QSE_AWK_RTX_VALTOSTR_CPLDUP;
+				if (qse_awk_rtx_valtostr (
+					run->rtx, val, &out) == QSE_NULL)
+				{
+					return -1;
+				}
+
+				p = out.u.cpldup.ptr;
+				l = out.u.cpldup.len;
+
+				cached.str.ptr = out.u.cpldup.ptr;
+				cached.str.len = out.u.cpldup.len;
+			}
+			else
+			{
+				p = cached.str.ptr;
+				l = cached.str.len;
+			}
+		}
 	}
 
-	*v = rv;
+	*str = p;
+	*len = l;
+
 	return 0;
-#endif
 }
 
-int Awk::Value::set (val_t* v)
+int Awk::Value::setVal (val_t* v)
 {
 	if (run == QSE_NULL) return -1;
-	return set (run, v);
+	return setVal (run, v);
 }
 
-int Awk::Value::set (Run* r, val_t* v)
+int Awk::Value::setVal (Run* r, val_t* v)
 {
 	if (run != QSE_NULL)
+	{
 		qse_awk_rtx_refdownval (run->rtx, val);
+		if (cached.str.ptr != QSE_NULL)
+		{
+			qse_awk_rtx_free (run->rtx, cached.str.ptr);
+			cached.str.ptr = QSE_NULL;
+			cached.str.len = 0;
+		}
+	}
+
+	QSE_ASSERT (cached.str.ptr == QSE_NULL);
 	qse_awk_rtx_refupval (r->rtx, v);
 
 	run = r;
@@ -299,81 +430,81 @@ int Awk::Value::set (Run* r, val_t* v)
 	return 0;
 }
 
-int Awk::Value::set (long_t v)
+int Awk::Value::setInt (long_t v)
 {
 	if (run == QSE_NULL) return -1;
-	return set (run, v);
+	return setInt (run, v);
 }
 
-int Awk::Value::set (Run* r, long_t v)
+int Awk::Value::setInt (Run* r, long_t v)
 {
 	val_t* tmp;
 	tmp = qse_awk_rtx_makeintval (r->rtx, v);
 	if (tmp == QSE_NULL) return -1;
 
-	int n = set (r, tmp);
+	int n = setVal (r, tmp);
 	QSE_ASSERT (n == 0);
 	return n;
 }
 
-int Awk::Value::set (real_t v)
+int Awk::Value::setReal (real_t v)
 {
 	if (run == QSE_NULL) return -1;
-	return set (run, v);
+	return setReal (run, v);
 }
 
-int Awk::Value::set (Run* r, real_t v)
+int Awk::Value::setReal (Run* r, real_t v)
 {
 	val_t* tmp;
 	tmp = qse_awk_rtx_makerealval (r->rtx, v);
 	if (tmp == QSE_NULL) return -1;
 			
-	int n = set (r, tmp);
+	int n = setVal (r, tmp);
 	QSE_ASSERT (n == 0);
 	return n;
 }
 
-int Awk::Value::set (const char_t* str, size_t len)
+int Awk::Value::setStr (const char_t* str, size_t len)
 {
 	if (run == QSE_NULL) return -1;
-	return set (run, str, len);
+	return setStr (run, str, len);
 }
 
-int Awk::Value::set (Run* r, const char_t* str, size_t len)
+int Awk::Value::setStr (Run* r, const char_t* str, size_t len)
 {
 	val_t* tmp;
 	tmp = qse_awk_rtx_makestrval (r->rtx, str, len);
 	if (tmp == QSE_NULL) return -1;
 
-	int n = set (r, tmp);
+	int n = setVal (r, tmp);
 	QSE_ASSERT (n == 0);
 	return n;
 }
 
-int Awk::Value::set (const char_t* str)
+int Awk::Value::setStr (const char_t* str)
 {
 	if (run == QSE_NULL) return -1;
-	return set (run, str);
+	return setStr (run, str);
 }
 
-int Awk::Value::set (Run* r, const char_t* str)
+int Awk::Value::setStr (Run* r, const char_t* str)
 {
 	val_t* tmp;
 	tmp = qse_awk_rtx_makestrval0 (r->rtx, str);
 	if (tmp == QSE_NULL) return -1;
 
-	int n = set (r, tmp);
+	int n = setVal (r, tmp);
 	QSE_ASSERT (n == 0);
 	return n;
 }
 
-int Awk::Value::setIndexed (const char_t* idx, size_t isz, val_t* v)
+int Awk::Value::setIndexedVal (const char_t* idx, size_t isz, val_t* v)
 {
 	if (run == QSE_NULL) return -1;
-	return setIndexed (run, idx, isz, v);
+	return setIndexedVal (run, idx, isz, v);
 }
 
-int Awk::Value::setIndexed (Run* r, const char_t* idx, size_t isz, val_t* v)
+int Awk::Value::setIndexedVal (Run* r, const char_t* idx, size_t isz, val_t* v)
 {
 	if (val->type != QSE_AWK_VAL_MAP)
 	{
@@ -433,63 +564,85 @@ int Awk::Value::setIndexed (Run* r, const char_t* idx, size_t isz, val_t* v)
 	return 0;
 }
 
-int Awk::Value::setIndexed (const char_t* idx, size_t isz, long_t v)
+int Awk::Value::setIndexedInt (const char_t* idx, size_t isz, long_t v)
 {
 	if (run == QSE_NULL) return -1;
-	return setIndexed (run, idx, isz, v);
+	return setIndexedInt (run, idx, isz, v);
 }
 
-int Awk::Value::setIndexed (Run* r, const char_t* idx, size_t isz, long_t v)
+int Awk::Value::setIndexedInt (Run* r, const char_t* idx, size_t isz, long_t v)
 {
 	val_t* tmp;
 	tmp = qse_awk_rtx_makeintval (r->rtx, v);
 	if (tmp == QSE_NULL) return -1;
 
 	qse_awk_rtx_refupval (r->rtx, tmp);
-	int n = setIndexed (r, idx, isz, tmp);
+	int n = setIndexedVal (r, idx, isz, tmp);
 	qse_awk_rtx_refdownval (r->rtx, tmp);
 
 	return n;
 }
 
-int Awk::Value::setIndexed (const char_t* idx, size_t isz, real_t v)
+int Awk::Value::setIndexedReal (const char_t* idx, size_t isz, real_t v)
 {
 	if (run == QSE_NULL) return -1;
-	return setIndexed (run, idx, isz, v);
+	return setIndexedReal (run, idx, isz, v);
 }
 
-int Awk::Value::setIndexed (Run* r, const char_t* idx, size_t isz, real_t v)
+int Awk::Value::setIndexedReal (Run* r, const char_t* idx, size_t isz, real_t v)
 {
 	val_t* tmp;
 	tmp = qse_awk_rtx_makerealval (r->rtx, v);
 	if (tmp == QSE_NULL) return -1;
 
 	qse_awk_rtx_refupval (r->rtx, tmp);
-	int n = setIndexed (r, idx, isz, tmp);
+	int n = setIndexedVal (r, idx, isz, tmp);
 	qse_awk_rtx_refdownval (r->rtx, tmp);
 
 	return n;
 }
 
-int Awk::Value::setIndexed (const char_t* idx, size_t isz, const char_t* str, size_t len)
+int Awk::Value::setIndexedStr (const char_t* idx, size_t isz, const char_t* str, size_t len)
 {
 	if (run == QSE_NULL) return -1;
-	return setIndexed (run, idx, isz, str, len);
+	return setIndexedStr (run, idx, isz, str, len);
 }
 
-int Awk::Value::setIndexed (Run* r, const char_t* idx, size_t isz, const char_t* str, size_t len)
+int Awk::Value::setIndexedStr (
+	Run* r, const char_t* idx, size_t isz, const char_t* str, size_t len)
 {
 	val_t* tmp;
 	tmp = qse_awk_rtx_makestrval (r->rtx, str, len);
 	if (tmp == QSE_NULL) return -1;
 
 	qse_awk_rtx_refupval (r->rtx, tmp);
-	int n = setIndexed (r, idx, isz, tmp);
+	int n = setIndexedVal (r, idx, isz, tmp);
 	qse_awk_rtx_refdownval (r->rtx, tmp);
 
 	return n;
 }
 
+int Awk::Value::setIndexedStr (const char_t* idx, size_t isz, const char_t* str)
+{
+	if (run == QSE_NULL) return -1;
+	return setIndexedStr (run, idx, isz, str);
+}
+
+int Awk::Value::setIndexedStr (
+	Run* r, const char_t* idx, size_t isz, const char_t* str)
+{
+	val_t* tmp;
+	tmp = qse_awk_rtx_makestrval0 (r->rtx, str);
+	if (tmp == QSE_NULL) return -1;
+
+	qse_awk_rtx_refupval (r->rtx, tmp);
+	int n = setIndexedVal (r, idx, isz, tmp);
+	qse_awk_rtx_refdownval (r->rtx, tmp);
+
+	return n;
+}
+
+
 bool Awk::Value::isIndexed () const
 {
 	QSE_ASSERT (val != QSE_NULL);
@@ -519,334 +672,10 @@ int Awk::Value::getIndexed (const char_t* idx, size_t isz, Value& v) const
 	}
 
 	// if v.set fails, it should return an error 
-	return v.set (run, (val_t*)QSE_MAP_VPTR(pair));
-}
-
-//////////////////////////////////////////////////////////////////
-// Awk::Argument
-//////////////////////////////////////////////////////////////////
-
-Awk::Argument::Argument (Run& run): run (&run), val (QSE_NULL)
-{
-	this->inum = 0;
-	this->rnum = 0.0;
-
-	this->str.ptr = QSE_NULL;
-	this->str.len = 0;
-}
-
-Awk::Argument::Argument (Run* run): run (run), val (QSE_NULL)
-{
-	this->inum = 0;
-	this->rnum = 0.0;
-
-	this->str.ptr = QSE_NULL;
-	this->str.len = 0;
-}
-
-Awk::Argument::Argument (): run (QSE_NULL), val (QSE_NULL)
-{
-	this->inum = 0;
-	this->rnum = 0.0;
-
-	this->str.ptr = QSE_NULL;
-	this->str.len = 0;
-}
-
-Awk::Argument::~Argument ()
-{
-	clear ();
-}
-
-void Awk::Argument::clear ()
-{
-	if (this->val == QSE_NULL)
-	{
-		/* case 1. not initialized.
-		 * case 2. initialized with the second init.
-		 * none of the cases. create a new string so the sttring
-		 * that str.ptr is pointing to doesn't have to be freed */
-		this->str.ptr = QSE_NULL;
-		this->str.len = 0;
-	}
-	else if (this->val->type == QSE_AWK_VAL_MAP)
-	{
-		QSE_ASSERT (this->run != QSE_NULL);
-
-		/* when the value is a map, str.ptr and str.len are
-		 * used for index iteration in getFirstIndex & getNextIndex */
-		qse_awk_rtx_refdownval (this->run->rtx, this->val);
-		this->val = QSE_NULL;
-	}
-	else
-	{
-		QSE_ASSERT (this->run != QSE_NULL);
-
-		if (this->str.ptr != QSE_NULL)
-		{
-			if (this->val->type != QSE_AWK_VAL_STR)
-			{
-				awk_t* awk = this->run->awk->awk;
-				qse_awk_free (awk, this->str.ptr);
-			}
-
-			this->str.ptr = QSE_NULL;
-			this->str.len = 0;
-		}
-
-		if (this->val != QSE_NULL) 
-		{
-			qse_awk_rtx_refdownval (this->run->rtx, this->val);
-			this->val = QSE_NULL;
-		}
-
-	}
-
-	this->rnum = 0.0;
-	this->inum = 0;
-}
-
-void* Awk::Argument::operator new (size_t n, awk_t* awk) throw ()
-{
-	void* ptr = qse_awk_alloc (awk, QSE_SIZEOF(awk) + n);
-	if (ptr == QSE_NULL) return QSE_NULL;
-
-	*(awk_t**)ptr = awk;
-	return (char*)ptr+QSE_SIZEOF(awk);
-}
-
-void* Awk::Argument::operator new[] (size_t n, awk_t* awk) throw ()
-{
-	void* ptr = qse_awk_alloc (awk, QSE_SIZEOF(awk) + n);
-	if (ptr == QSE_NULL) return QSE_NULL;
-
-	*(awk_t**)ptr = awk;
-	return (char*)ptr+QSE_SIZEOF(awk);
-}
-
-#if !defined(__BORLANDC__)
-void Awk::Argument::operator delete (void* ptr, awk_t* awk)
-{
-	qse_awk_free (awk, (char*)ptr-QSE_SIZEOF(awk));
-}
-
-void Awk::Argument::operator delete[] (void* ptr, awk_t* awk)
-{
-	qse_awk_free (awk, (char*)ptr-QSE_SIZEOF(awk));
-}
-#endif
-
-void Awk::Argument::operator delete (void* ptr)
-{
-	void* p = (char*)ptr-QSE_SIZEOF(awk_t*);
-	qse_awk_free (*(awk_t**)p, p);
-}
-
-void Awk::Argument::operator delete[] (void* ptr)
-{
-	void* p = (char*)ptr-QSE_SIZEOF(awk_t*);
-	qse_awk_free (*(awk_t**)p, p);
-}
-
-int Awk::Argument::init (val_t* v)
-{
-	// this method is used internally only
-	// and should never be called more than once 
-	QSE_ASSERT (this->val == QSE_NULL);
-	QSE_ASSERT (v != QSE_NULL);
-
-	qse_awk_rtx_refupval (this->run->rtx, v);
-	this->val = v;
-
-	if (v->type == QSE_AWK_VAL_STR)
-	{
-		int n = qse_awk_rtx_valtonum (
-			this->run->rtx, v, &this->inum, &this->rnum);
-		if (n == 0) 
-		{
-			this->rnum = (qse_real_t)this->inum;
-			this->str.ptr = ((qse_awk_val_str_t*)this->val)->ptr;
-			this->str.len = ((qse_awk_val_str_t*)this->val)->len;
-			return 0;
-		}
-		else if (n == 1) 
-		{
-			this->inum = (qse_long_t)this->rnum;
-			this->str.ptr = ((qse_awk_val_str_t*)this->val)->ptr;
-			this->str.len = ((qse_awk_val_str_t*)this->val)->len;
-			return 0;
-		}
-	}
-	else if (v->type == QSE_AWK_VAL_INT)
-	{
-		this->inum = ((qse_awk_val_int_t*)v)->val;
-		this->rnum = (qse_real_t)((qse_awk_val_int_t*)v)->val;
-
-		this->str.ptr = qse_awk_rtx_valtocpldup (
-			this->run->rtx, v, &this->str.len);
-		if (this->str.ptr != QSE_NULL) return 0;
-	}
-	else if (v->type == QSE_AWK_VAL_REAL)
-	{
-		this->inum = (qse_long_t)((qse_awk_val_real_t*)v)->val;
-		this->rnum = ((qse_awk_val_real_t*)v)->val;
-
-		this->str.ptr = qse_awk_rtx_valtocpldup (
-			this->run->rtx, v, &this->str.len);
-		if (this->str.ptr != QSE_NULL) return 0;
-	}
-	else if (v->type == QSE_AWK_VAL_NIL)
-	{
-		this->inum = 0;
-		this->rnum = 0.0;
-
-		this->str.ptr = qse_awk_rtx_valtocpldup (
-			this->run->rtx, v, &this->str.len);
-		if (this->str.ptr != QSE_NULL) return 0;
-	}
-	else if (v->type == QSE_AWK_VAL_MAP)
-	{
-		this->inum = 0;
-		this->rnum = 0.0;
-		this->str.ptr = QSE_NULL;
-		this->str.len = 0;
-		return 0;
-	}
-
-	// an error has occurred
-	qse_awk_rtx_refdownval (this->run->rtx, v);
-	this->val = QSE_NULL;
-	return -1;
-}
-
-int Awk::Argument::init (const char_t* str, size_t len)
-{
-	QSE_ASSERT (this->val == QSE_NULL);
-
-	this->str.ptr = (char_t*)str;
-	this->str.len = len;
-
-	if (qse_awk_rtx_strtonum (
-		this->run->rtx, 0, 
-		str, len, &this->inum, &this->rnum) == 0)
-	{
-		this->rnum = (real_t)this->inum;
-	}
-	else
-	{
-		this->inum = (long_t)this->rnum;
-	}
-
-	return 0;
-}
-
-Awk::long_t Awk::Argument::toInt () const
-{
-	return this->inum;
-}
-
-Awk::real_t Awk::Argument::toReal () const
-{
-	return this->rnum;
-}
-
-const Awk::char_t* Awk::Argument::toStr (size_t* len) const
-{
-
-	if (this->val != QSE_NULL && 
-	    this->val->type == QSE_AWK_VAL_MAP)
-	{
-		*len = 0;
-		return QSE_T("");
-	}
-	else if (this->str.ptr == QSE_NULL)
-	{
-		*len = 0;
-		return QSE_T("");
-	}
-	else
-	{
-		*len = this->str.len;
-		return this->str.ptr;
-	}
-}
-
-bool Awk::Argument::isIndexed () const
-{
-	if (this->val == QSE_NULL) return false;
-	return this->val->type == QSE_AWK_VAL_MAP;
-}
-
-int Awk::Argument::getIndexed (const char_t* idxptr, Awk::Argument& val) const
-{
-	return getIndexed (idxptr, qse_strlen(idxptr), val);
-}
-
-int Awk::Argument::getIndexed (
-	const char_t* idxptr, size_t idxlen, Awk::Argument& val) const
-{
-	val.clear ();
-
-	// not initialized yet. val is just nil. not an error
-	if (this->val == QSE_NULL) return 0;
-	// not a map. val is just nil. not an error 
-	if (this->val->type != QSE_AWK_VAL_MAP) return 0;
-
-	// get the value from the map.
-	qse_awk_val_map_t* m = (qse_awk_val_map_t*)this->val;
-	pair_t* pair = qse_map_search (m->map, idxptr, idxlen);
-
-	// the key is not found. it is not an error. val is just nil 
-	if (pair == QSE_NULL) return 0; 
-
-	// if val.init fails, it should return an error 
-	return val.init ((val_t*)QSE_MAP_VPTR(pair));
-}
-
-int Awk::Argument::getIndexed (long_t idx, Argument& val) const
-{
-	val.clear ();
-
-	// not initialized yet. val is just nil. not an error
-	if (this->val == QSE_NULL) return 0;
-
-	// not a map. val is just nil. not an error 
-	if (this->val->type != QSE_AWK_VAL_MAP) return 0;
-
-	char_t ri[128];
-
-	int rl = Awk::sprintf (
-		(awk_t*)this->run->awk, ri, QSE_COUNTOF(ri), 
-	#if QSE_SIZEOF_LONG_LONG > 0
-		QSE_T("%lld"), (long long)idx
-	#elif QSE_SIZEOF___INT64 > 0
-		QSE_T("%I64d"), (__int64)idx
-	#elif QSE_SIZEOF_LONG > 0
-		QSE_T("%ld"), (long)idx
-	#elif QSE_SIZEOF_INT > 0
-		QSE_T("%d"), (int)idx
-	#else
-		#error unsupported size	
-	#endif
-		);
-
-	if (rl < 0)
-	{
-		run->setError (ERR_INTERN, 0, QSE_NULL, 0);
-		return -1;
-	}
-
-	// get the value from the map.
-	qse_awk_val_map_t* m = (qse_awk_val_map_t*)this->val;
-	pair_t* pair = qse_map_search (m->map, ri, rl);
-
-	// the key is not found. it is not an error. val is just nil 
-	if (pair == QSE_NULL) return 0; 
-
-	// if val.init fails, it should return an error 
-	return val.init ((val_t*)QSE_MAP_VPTR(pair));
+	return v.setVal (run, (val_t*)QSE_MAP_VPTR(pair));
 }
 
+#if 0
 int Awk::Argument::getFirstIndex (Awk::Argument& val) const
 {
 	val.clear ();
@@ -895,299 +724,6 @@ int Awk::Argument::getNextIndex (Awk::Argument& val) const
 	return 1;
 }
 
-//////////////////////////////////////////////////////////////////
-// Awk::Return
-//////////////////////////////////////////////////////////////////
-
-Awk::Return::Return (Run& run): run(&run), val(qse_awk_val_nil)
-{
-}
-
-Awk::Return::Return (Run* run): run(run), val(qse_awk_val_nil)
-{
-}
-
-Awk::Return::~Return ()
-{
-	clear ();
-}
-
-Awk::val_t* Awk::Return::toVal () const
-{
-	return this->val; 
-}
-
-Awk::Return::operator Awk::val_t* () const 
-{
-	return this->val; 
-}
-
-int Awk::Return::set (long_t v)
-{
-	if (this->run == QSE_NULL) return -1;
-
-	val_t* x = qse_awk_rtx_makeintval (this->run->rtx, v);
-	if (x == QSE_NULL) return -1;
-
-	qse_awk_rtx_refdownval (this->run->rtx, this->val);
-	this->val = x;
-	qse_awk_rtx_refupval (this->run->rtx, this->val);
-
-	return 0;
-}
-
-int Awk::Return::set (real_t v)
-{
-	if (this->run == QSE_NULL) return -1;
-
-	val_t* x = qse_awk_rtx_makerealval (this->run->rtx, v);
-	if (x == QSE_NULL) return -1;
-
-	qse_awk_rtx_refdownval (this->run->rtx, this->val);
-	this->val = x;
-	qse_awk_rtx_refupval (this->run->rtx, this->val);
-
-	return 0;
-}
-
-int Awk::Return::set (const char_t* ptr, size_t len)
-{
-	if (this->run == QSE_NULL) return -1;
-
-	val_t* x = qse_awk_rtx_makestrval (this->run->rtx, ptr, len);
-	if (x == QSE_NULL) return -1;
-
-	qse_awk_rtx_refdownval (this->run->rtx, this->val);
-	this->val = x;
-	qse_awk_rtx_refupval (this->run->rtx, this->val);
-	return 0;
-}
-
-bool Awk::Return::isIndexed () const
-{
-	if (this->val == QSE_NULL) return false;
-	return this->val->type == QSE_AWK_VAL_MAP;
-}
-
-int Awk::Return::setIndexed (const char_t* idx, size_t iln, long_t v)
-{
-	if (this->run == QSE_NULL) return -1;
-
-	int opt = this->run->awk->getOption();
-	if ((opt & OPT_MAPTOVAR) == 0)
-	{
-		/* refer to run_return in run.c */
-		this->run->setError (ERR_MAPNOTALLOWED, 0, QSE_NULL, 0);
-		return -1;
-	}
-
-	if (this->val->type != QSE_AWK_VAL_MAP)
-	{
-		val_t* x = qse_awk_rtx_makemapval (this->run->rtx);
-		if (x == QSE_NULL) return -1;
-
-		qse_awk_rtx_refupval (this->run->rtx, x);
-
-		val_t* x2 = qse_awk_rtx_makeintval (this->run->rtx, v);
-		if (x2 == QSE_NULL)
-		{
-			qse_awk_rtx_refdownval (this->run->rtx, x);
-			return -1;
-		}
-
-		qse_awk_rtx_refupval (this->run->rtx, x2);
-
-		pair_t* pair = qse_map_upsert (
-			((qse_awk_val_map_t*)x)->map,
-			(char_t*)idx, iln, x2, 0);
-		if (pair == QSE_NULL)
-		{
-			qse_awk_rtx_refdownval (this->run->rtx, x2);
-			qse_awk_rtx_refdownval (this->run->rtx, x);
-			this->run->setError (ERR_NOMEM, 0, QSE_NULL, 0);
-			return -1;
-		}
-
-		qse_awk_rtx_refdownval (this->run->rtx, this->val);
-		this->val = x;
-	}
-	else
-	{
-		val_t* x2 = qse_awk_rtx_makeintval (this->run->rtx, v);
-		if (x2 == QSE_NULL) return -1;
-
-		qse_awk_rtx_refupval (this->run->rtx, x2);
-
-		pair_t* pair = qse_map_upsert (
-			((qse_awk_val_map_t*)this->val)->map, 
-			(char_t*)idx, iln, x2, 0);
-		if (pair == QSE_NULL)
-		{
-			qse_awk_rtx_refdownval (this->run->rtx, x2);
-			this->run->setError (ERR_NOMEM, 0, QSE_NULL, 0);
-			return -1;
-		}
-	}
-
-	return 0;
-}
-
-int Awk::Return::setIndexed (const char_t* idx, size_t iln, real_t v)
-{
-	if (this->run == QSE_NULL) return -1;
-
-	int opt = this->run->awk->getOption();
-	if ((opt & OPT_MAPTOVAR) == 0)
-	{
-		/* refer to run_return in run.c */
-		this->run->setError (ERR_MAPNOTALLOWED, 0, QSE_NULL, 0);
-		return -1;
-	}
-
-	if (this->val->type != QSE_AWK_VAL_MAP)
-	{
-		val_t* x = qse_awk_rtx_makemapval (this->run->rtx);
-		if (x == QSE_NULL) return -1;
-
-		qse_awk_rtx_refupval (this->run->rtx, x);
-
-		val_t* x2 = qse_awk_rtx_makerealval (this->run->rtx, v);
-		if (x2 == QSE_NULL)
-		{
-			qse_awk_rtx_refdownval (this->run->rtx, x);
-			return -1;
-		}
-
-		qse_awk_rtx_refupval (this->run->rtx, x2);
-
-		pair_t* pair = qse_map_upsert (
-			((qse_awk_val_map_t*)x)->map, 
-			(char_t*)idx, iln, x2, 0);
-		if (pair == QSE_NULL)
-		{
-			qse_awk_rtx_refdownval (this->run->rtx, x2);
-			qse_awk_rtx_refdownval (this->run->rtx, x);
-			this->run->setError (ERR_NOMEM, 0, QSE_NULL, 0);
-			return -1;
-		}
-
-		qse_awk_rtx_refdownval (this->run->rtx, this->val);
-		this->val = x;
-	}
-	else
-	{
-		val_t* x2 = qse_awk_rtx_makerealval (this->run->rtx, v);
-		if (x2 == QSE_NULL) return -1;
-
-		qse_awk_rtx_refupval (this->run->rtx, x2);
-
-		pair_t* pair = qse_map_upsert (
-			((qse_awk_val_map_t*)this->val)->map,
-			(char_t*)idx, iln, x2, 0);
-		if (pair == QSE_NULL)
-		{
-			qse_awk_rtx_refdownval (this->run->rtx, x2);
-			this->run->setError (ERR_NOMEM, 0, QSE_NULL, 0);
-			return -1;
-		}
-	}
-
-	return 0;
-}
-
-int Awk::Return::setIndexed (const char_t* idx, size_t iln, const char_t* str, size_t sln)
-{
-	if (this->run == QSE_NULL) return -1;
-
-	int opt = this->run->awk->getOption();
-	if ((opt & OPT_MAPTOVAR) == 0)
-	{
-		/* refer to run_return in run.c */
-		this->run->setError (ERR_MAPNOTALLOWED, 0, QSE_NULL, 0);
-		return -1;
-	}
-
-	if (this->val->type != QSE_AWK_VAL_MAP)
-	{
-		val_t* x = qse_awk_rtx_makemapval (this->run->rtx);
-		if (x == QSE_NULL) return -1;
-
-		qse_awk_rtx_refupval (this->run->rtx, x);
-
-		val_t* x2 = qse_awk_rtx_makestrval (this->run->rtx, str, sln);
-		if (x2 == QSE_NULL)
-		{
-			qse_awk_rtx_refdownval (this->run->rtx, x);
-			return -1;
-		}
-
-		qse_awk_rtx_refupval (this->run->rtx, x2);
-
-		pair_t* pair = qse_map_upsert (
-			((qse_awk_val_map_t*)x)->map, 
-			(char_t*)idx, iln, x2, 0);
-		if (pair == QSE_NULL)
-		{
-			qse_awk_rtx_refdownval (this->run->rtx, x2);
-			qse_awk_rtx_refdownval (this->run->rtx, x);
-			this->run->setError (ERR_NOMEM, 0, QSE_NULL, 0);
-			return -1;
-		}
-
-		qse_awk_rtx_refdownval (this->run->rtx, this->val);
-		this->val = x;
-	}
-	else
-	{
-		val_t* x2 = qse_awk_rtx_makestrval (this->run->rtx, str, sln);
-		if (x2 == QSE_NULL) return -1;
-
-		qse_awk_rtx_refupval (this->run->rtx, x2);
-
-		pair_t* pair = qse_map_upsert (
-			((qse_awk_val_map_t*)this->val)->map, 
-			(char_t*)idx, iln, x2, 0);
-		if (pair == QSE_NULL)
-		{
-			qse_awk_rtx_refdownval (this->run->rtx, x2);
-			this->run->setError (ERR_NOMEM, 0, QSE_NULL, 0);
-			return -1;
-		}
-	}
-
-	return 0;
-}
-
-int Awk::Return::setIndexed (long_t idx, long_t v)
-{
-	if (this->run == QSE_NULL) return -1;
-
-	char_t ri[128];
-
-	int rl = Awk::sprintf (
-		(awk_t*)this->run->awk, ri, QSE_COUNTOF(ri), 
-	#if QSE_SIZEOF_LONG_LONG > 0
-		QSE_T("%lld"), (long long)idx
-	#elif QSE_SIZEOF___INT64 > 0
-		QSE_T("%I64d"), (__int64)idx
-	#elif QSE_SIZEOF_LONG > 0
-		QSE_T("%ld"), (long)idx
-	#elif QSE_SIZEOF_INT > 0
-		QSE_T("%d"), (int)idx
-	#else
-		#error unsupported size	
-	#endif
-		);
-
-	if (rl < 0)
-	{
-		this->run->setError (ERR_INTERN, 0, QSE_NULL, 0);
-		return -1;
-	}
-
-	return setIndexed (ri, rl, v);
-}
-
 int Awk::Return::setIndexed (long_t idx, real_t v)
 {
 	if (this->run == QSE_NULL) return -1;
@@ -1217,42 +753,7 @@ int Awk::Return::setIndexed (long_t idx, real_t v)
 
 	return setIndexed (ri, rl, v);
 }
-
-int Awk::Return::setIndexed (long_t idx, const char_t* str, size_t sln)
-{
-	if (this->run == QSE_NULL) return -1;
-
-	char_t ri[128];
-
-	int rl = Awk::sprintf (
-		(awk_t*)this->run->awk, ri, QSE_COUNTOF(ri), 
-	#if QSE_SIZEOF_LONG_LONG > 0
-		QSE_T("%lld"), (long long)idx
-	#elif QSE_SIZEOF___INT64 > 0
-		QSE_T("%I64d"), (__int64)idx
-	#elif QSE_SIZEOF_LONG > 0
-		QSE_T("%ld"), (long)idx
-	#elif QSE_SIZEOF_INT > 0
-		QSE_T("%d"), (int)idx
-	#else
-		#error unsupported size	
-	#endif
-		);
-
-	if (rl < 0)
-	{
-		this->run->setError (ERR_INTERN, 0, QSE_NULL, 0);
-		return -1;
-	}
-
-	return setIndexed (ri, rl, str, sln);
-}
-
-void Awk::Return::clear ()
-{
-	qse_awk_rtx_refdownval (this->run->rtx, this->val);
-	this->val = qse_awk_val_nil;
-}
+#endif
 
 //////////////////////////////////////////////////////////////////
 // Awk::Run
@@ -1391,19 +892,17 @@ int Awk::Run::setGlobal (int id, const char_t* ptr, size_t len)
 	return n;
 }
 
-int Awk::Run::setGlobal (int id, const Return& gbl)
+int Awk::Run::setGlobal (int id, const Value& gbl)
 {
 	QSE_ASSERT (this->rtx != QSE_NULL);
 
-	return qse_awk_rtx_setgbl (this->rtx, id, gbl.toVal());
+	return qse_awk_rtx_setgbl (this->rtx, id, (val_t*)gbl);
 }
 
-int Awk::Run::getGlobal (int id, Argument& gbl) const
+int Awk::Run::getGlobal (int id, Value& g) const
 {
 	QSE_ASSERT (this->rtx != QSE_NULL);
-
-	gbl.clear ();
-	return gbl.init (qse_awk_rtx_getgbl (this->rtx, id));
+	return g.setVal ((Run*)this, qse_awk_rtx_getgbl (this->rtx, id));
 }
 
 //////////////////////////////////////////////////////////////////
@@ -1753,37 +1252,44 @@ int Awk::loop ()
 	return n;
 }
 
-int Awk::call (const char_t* name, const Return* args, size_t nargs)
+int Awk::call (const char_t* name, Value* ret, const Value* args, size_t nargs)
 {
 	QSE_ASSERT (awk != QSE_NULL);
 	QSE_ASSERT (runctx.rtx != QSE_NULL);
 
+	val_t* buf[16];
 	val_t** ptr = QSE_NULL;
 
 	if (args != QSE_NULL)
 	{
-		ptr = (val_t**) qse_awk_alloc (awk, QSE_SIZEOF(val_t*) * nargs);
-		if (ptr == QSE_NULL)
+		if (nargs <= QSE_COUNTOF(buf)) ptr = buf;
+		else
 		{
-			runctx.setError (ERR_NOMEM);
-			return -1;
+			ptr = (val_t**) qse_awk_alloc (
+				awk, QSE_SIZEOF(val_t*) * nargs);
+			if (ptr == QSE_NULL)
+			{
+				runctx.setError (ERR_NOMEM);
+				return -1;
+			}
 		}
 
-		for (size_t i = 0; i < nargs; i++) ptr[i] = args[i].val;
+		for (size_t i = 0; i < nargs; i++) ptr[i] = (val_t*)args[i];
 	}
 
-	val_t* ret = qse_awk_rtx_call (runctx.rtx, name, ptr, nargs);
+	val_t* rv = qse_awk_rtx_call (runctx.rtx, name, ptr, nargs);
 
-	if (ptr != QSE_NULL) qse_awk_free (awk, ptr);
+	if (ptr != QSE_NULL && ptr != buf) qse_awk_free (awk, ptr);
 
-	if (ret == QSE_NULL) 
+	if (rv == QSE_NULL) 
 	{
 		retrieveError (runctx.rtx);
 		return -1;
 	}
 
-// TODO: how can i store it???
-	qse_awk_rtx_refdownval (runctx.rtx, ret);
+	ret->setVal (&runctx, rv);
+
+	qse_awk_rtx_refdownval (runctx.rtx, rv);
 	return 0;
 }
 
@@ -1796,7 +1302,6 @@ void Awk::stop ()
 int Awk::dispatchFunction (Run* run, const char_t* name, size_t len)
 {
 	pair_t* pair;
-	awk_t* awk = run->awk->awk;
 
 	pair = qse_map_search (functionMap, name, len);
 	if (pair == QSE_NULL) 
@@ -1810,34 +1315,35 @@ int Awk::dispatchFunction (Run* run, const char_t* name, size_t len)
 
 	size_t i, nargs = qse_awk_rtx_getnargs(run->rtx);
 
-	//Argument* args = QSE_NULL;
-	//try { args = new Argument [nargs]; } catch (...)  {}
-	Argument* args = new(awk) Argument[nargs];
-	if (args == QSE_NULL) 
+	Value buf[16];
+	Value* args;
+	if (nargs <= QSE_COUNTOF(buf)) args = buf;
+	else
 	{
-		run->setError (ERR_NOMEM, 0, QSE_NULL, 0);
-		return -1;
+		args = new(run) Value[nargs];
+		if (args == QSE_NULL) 
+		{
+			run->setError (ERR_NOMEM, 0, QSE_NULL, 0);
+			return -1;
+		}
 	}
 
 	for (i = 0; i < nargs; i++)
 	{
-		args[i].run = run; // dirty late initialization 
-		                   // due to c++ array creation limitation.
-
 		val_t* v = qse_awk_rtx_getarg (run->rtx, i);
-		if (args[i].init (v) == -1)
+		if (args[i].setVal (run, v) == -1)
 		{
 			run->setError (ERR_NOMEM, 0, QSE_NULL, 0);
-			delete[] args;
+			if (args != buf) delete[] args;
 			return -1;
 		}
 	}
 	
-	Return ret (run);
+	Value ret (run);
 
 	int n = (this->*handler) (*run, ret, args, nargs, name, len);
 
-	delete[] args;
+	if (args != buf) delete[] args;
 
 	if (n <= -1) 
 	{
@@ -1846,7 +1352,7 @@ int Awk::dispatchFunction (Run* run, const char_t* name, size_t len)
 		return -1;
 	}
 
-	qse_awk_rtx_setretval (run->rtx, ret);
+	qse_awk_rtx_setretval (run->rtx, ret.toVal());
 	return 0;
 }
 
@@ -1996,7 +1502,7 @@ bool Awk::onLoopEnter (Run& run)
 	return true;
 }
 
-void Awk::onLoopExit (Run& run, const Argument& ret)
+void Awk::onLoopExit (Run& run, const Value& ret)
 {
 }
 
@@ -2160,8 +1666,8 @@ void Awk::onLoopExit (rtx_t* rtx, val_t* ret, void* data)
 {
 	Run* run = (Run*)data;
 
-	Argument x (run);
-	if (x.init (ret) == -1) 
+	Value x;
+	if (x.setVal (run, ret) == -1) 
 		qse_awk_rtx_seterrnum (run->rtx, (errnum_t)ERR_NOMEM);
 	else run->awk->onLoopExit (*run, x);
 }
diff --git a/qse/lib/awk/StdAwk.cpp b/qse/lib/awk/StdAwk.cpp
index 1d560ff3..67c3f389 100644
--- a/qse/lib/awk/StdAwk.cpp
+++ b/qse/lib/awk/StdAwk.cpp
@@ -1,5 +1,5 @@
 /*
- * $Id: StdAwk.cpp 226 2009-07-09 12:46:14Z hyunghwan.chung $
+ * $Id: StdAwk.cpp 229 2009-07-12 13:06:01Z hyunghwan.chung $
  *
    Copyright 2006-2009 Chung, Hyung-Hwan.
 
@@ -81,10 +81,10 @@ void StdAwk::close ()
 	Awk::close ();
 }
 
-int StdAwk::sin (Run& run, Return& ret, const Argument* args, size_t nargs, 
+int StdAwk::sin (Run& run, Value& ret, const Value* args, size_t nargs, 
 	const char_t* name, size_t len)
 {
-	return ret.set (
+	return ret.setReal (
 	#if defined(HAVE_SINL)
 		(real_t)::sinl(args[0].toReal())
 	#elif defined(HAVE_SIN)
@@ -97,10 +97,10 @@ int StdAwk::sin (Run& run, Return& ret, const Argument* args, size_t nargs,
 	);
 }
 
-int StdAwk::cos (Run& run, Return& ret, const Argument* args, size_t nargs,
+int StdAwk::cos (Run& run, Value& ret, const Value* args, size_t nargs,
 	const char_t* name, size_t len)
 {
-	return ret.set (
+	return ret.setReal (
 	#if defined(HAVE_COSL)
 		(real_t)::cosl(args[0].toReal())
 	#elif defined(HAVE_COS)
@@ -113,10 +113,10 @@ int StdAwk::cos (Run& run, Return& ret, const Argument* args, size_t nargs,
 	);
 }
 
-int StdAwk::tan (Run& run, Return& ret, const Argument* args, size_t nargs,
+int StdAwk::tan (Run& run, Value& ret, const Value* args, size_t nargs,
 	const char_t* name, size_t len)
 {
-	return ret.set (
+	return ret.setReal (
 	#if defined(HAVE_TANL)
 		(real_t)::tanl(args[0].toReal())
 	#elif defined(HAVE_TAN)
@@ -129,10 +129,10 @@ int StdAwk::tan (Run& run, Return& ret, const Argument* args, size_t nargs,
 	);
 }
 
-int StdAwk::atan (Run& run, Return& ret, const Argument* args, size_t nargs,
+int StdAwk::atan (Run& run, Value& ret, const Value* args, size_t nargs,
 	const char_t* name, size_t len)
 {
-	return ret.set (
+	return ret.setReal (
 	#if defined(HAVE_ATANL)
 		(real_t)::atanl(args[0].toReal())
 	#elif defined(HAVE_ATAN)
@@ -145,10 +145,10 @@ int StdAwk::atan (Run& run, Return& ret, const Argument* args, size_t nargs,
 	);
 }
 
-int StdAwk::atan2 (Run& run, Return& ret, const Argument* args, size_t nargs,
+int StdAwk::atan2 (Run& run, Value& ret, const Value* args, size_t nargs,
 	const char_t* name, size_t len)
 {
-	return ret.set (
+	return ret.setReal (
 	#if defined(HAVE_ATAN2L)
 		(real_t)::atan2l(args[0].toReal(), args[1].toReal())
 	#elif defined(HAVE_ATAN2)
@@ -161,10 +161,10 @@ int StdAwk::atan2 (Run& run, Return& ret, const Argument* args, size_t nargs,
 	);
 }
 
-int StdAwk::log (Run& run, Return& ret, const Argument* args, size_t nargs,
+int StdAwk::log (Run& run, Value& ret, const Value* args, size_t nargs,
 	const char_t* name, size_t len)
 {
-	return ret.set (
+	return ret.setReal (
 	#if defined(HAVE_LOGL)
 		(real_t)::logl(args[0].toReal())
 	#elif defined(HAVE_LOG)
@@ -177,10 +177,10 @@ int StdAwk::log (Run& run, Return& ret, const Argument* args, size_t nargs,
 	);
 }
 
-int StdAwk::exp (Run& run, Return& ret, const Argument* args, size_t nargs,
+int StdAwk::exp (Run& run, Value& ret, const Value* args, size_t nargs,
 	const char_t* name, size_t len)
 {
-	return ret.set (
+	return ret.setReal (
 	#if defined(HAVE_EXPL)
 		(real_t)::expl(args[0].toReal())
 	#elif defined(HAVE_EXP)
@@ -193,10 +193,10 @@ int StdAwk::exp (Run& run, Return& ret, const Argument* args, size_t nargs,
 	);
 }
 
-int StdAwk::sqrt (Run& run, Return& ret, const Argument* args, size_t nargs,
+int StdAwk::sqrt (Run& run, Value& ret, const Value* args, size_t nargs,
 	const char_t* name, size_t len)
 {
-	return ret.set (
+	return ret.setReal (
 	#if defined(HAVE_SQRTL)
 		(real_t)::sqrtl(args[0].toReal())
 	#elif defined(HAVE_SQRT)
@@ -209,19 +209,19 @@ int StdAwk::sqrt (Run& run, Return& ret, const Argument* args, size_t nargs,
 	);
 }
 
-int StdAwk::fnint (Run& run, Return& ret, const Argument* args, size_t nargs,
+int StdAwk::fnint (Run& run, Value& ret, const Value* args, size_t nargs,
 	const char_t* name, size_t len)
 {
-	return ret.set (args[0].toInt());
+	return ret.setInt (args[0].toInt());
 }
 
-int StdAwk::rand (Run& run, Return& ret, const Argument* args, size_t nargs,
+int StdAwk::rand (Run& run, Value& ret, const Value* args, size_t nargs,
 	const char_t* name, size_t len)
 {
-	return ret.set ((real_t)(::rand() % RAND_MAX) / RAND_MAX);
+	return ret.setReal ((real_t)(::rand() % RAND_MAX) / RAND_MAX);
 }
 
-int StdAwk::srand (Run& run, Return& ret, const Argument* args, size_t nargs,
+int StdAwk::srand (Run& run, Value& ret, const Value* args, size_t nargs,
 	const char_t* name, size_t len)
 {
 	unsigned int prevSeed = this->seed;
@@ -240,19 +240,19 @@ int StdAwk::srand (Run& run, Return& ret, const Argument* args, size_t nargs,
 	}
 
 	::srand (this->seed);
-	return ret.set ((long_t)prevSeed);
+	return ret.setInt ((long_t)prevSeed);
 }
 
-int StdAwk::system (Run& run, Return& ret, const Argument* args, size_t nargs,
+int StdAwk::system (Run& run, Value& ret, const Value* args, size_t nargs,
 	const char_t* name, size_t len)
 {
 	size_t l;
 	const char_t* ptr = args[0].toStr(&l);
 
 #ifdef _WIN32
-	return ret.set ((long_t)::_tsystem(ptr));
+	return ret.setInt ((long_t)::_tsystem(ptr));
 #elif defined(QSE_CHAR_IS_MCHAR)
-	return ret.set ((long_t)::system(ptr));
+	return ret.setInt ((long_t)::system(ptr));
 #else
 	char* mbs = (char*) qse_awk_alloc ((awk_t*)(Awk*)run, l*5+1);
 	if (mbs == QSE_NULL) return -1;
@@ -271,7 +271,7 @@ int StdAwk::system (Run& run, Return& ret, const Argument* args, size_t nargs,
 	}
 
 	mbs[mbl] = '\0';
-	int n = ret.set ((long_t)::system(mbs));
+	int n = ret.setInt ((long_t)::system(mbs));
 
 	qse_awk_free ((awk_t*)(Awk*)run, mbs);
 	return n;
diff --git a/qse/samples/awk/awk05.cpp b/qse/samples/awk/awk05.cpp
index 653a55b3..3b7c168e 100644
--- a/qse/samples/awk/awk05.cpp
+++ b/qse/samples/awk/awk05.cpp
@@ -34,33 +34,13 @@ static void print_error (const qse_char_t* msg)
 	print_error (0, msg);
 }
 
-static int awk_main (int argc, qse_char_t* argv[])
+static int run_awk (QSE::StdAwk& awk)
 {
-	QSE::StdAwk awk;
-	QSE::StdAwk::Run* run;
-
-	// initialize awk
-	if (awk.open() <= -1)
-	{
-		print_error (awk.getErrorMessage());
-		return -1;
-	}
-
 	// ARGV[0]
-	if (awk.addArgument (QSE_T("awk05")) <= -1)
-	{
-		print_error (awk.getErrorMessage());
-		awk.close ();
-		return -1;
-	}
+	if (awk.addArgument (QSE_T("awk05")) <= -1) return -1;
 
 	// ARGV[1] and/or the first console input file
-	if (awk.addArgument (QSE_T("awk05.cpp")) <= -1)
-	{
-		print_error (awk.getErrorMessage());
-		awk.close ();
-		return -1;
-	}
+	if (awk.addArgument (QSE_T("awk05.cpp")) <= -1) return -1;
 
 	const qse_char_t* script = QSE_T(
 		"BEGIN { print \">> PRINT ALL LINES WHOSE LENGTH IS GREATER THAN 0\"; }\n" 
@@ -72,24 +52,23 @@ static int awk_main (int argc, qse_char_t* argv[])
 	QSE::StdAwk::SourceFile out (QSE_T("awk05.out"));
 
 	// parse the script string and deparse it to awk05.out.
-	run = awk.parse (&in, &out);
-	if (run == QSE_NULL)
-	{
-		print_error (awk.getErrorLine(), awk.getErrorMessage());
-		awk.close ();
-		return -1;
-	}
+	if (awk.parse (&in, &out) == QSE_NULL) return -1;
 
 	// execute the BEGIN, pattern-action, END blocks.
-	if (awk.loop () <= -1)
-	{
-		print_error (awk.getErrorLine(), awk.getErrorMessage());
-		awk.close ();
-		return -1;
-	}
+	return awk.loop ();
+}
+
+static int awk_main (int argc, qse_char_t* argv[])
+{
+	QSE::StdAwk awk;
+
+	int ret = awk.open ();
+	if (ret >= 0) ret = run_awk (awk);
+
+	if (ret <= -1) print_error (awk.getErrorLine(), awk.getErrorMessage());
 
 	awk.close ();
-	return 0;
+	return ret;
 }
 
 int qse_main (int argc, qse_achar_t* argv[])
diff --git a/qse/samples/awk/awk06.cpp b/qse/samples/awk/awk06.cpp
index 653a55b3..079da862 100644
--- a/qse/samples/awk/awk06.cpp
+++ b/qse/samples/awk/awk06.cpp
@@ -29,67 +29,59 @@ static void print_error (unsigned long line, const qse_char_t* msg)
 	
 }
 
-static void print_error (const qse_char_t* msg)
+static int run_awk (QSE::StdAwk& awk)
 {
-	print_error (0, msg);
+	QSE::StdAwk::Run* run;
+
+	const qse_char_t* script = QSE_T(
+		"function add (a, b) { return a + b }\n"
+		"function mul (a, b) { return a * b }\n"
+		"function div (a, b) { return a / b }\n"
+	);
+
+	QSE::StdAwk::SourceString in (script);
+	QSE::StdAwk::SourceFile out (QSE_T("awk06.out"));
+
+	// parse the script and deparse it to awk06.out
+	run = awk.parse (&in, &out);
+	if (run == QSE_NULL) return -1;
+
+	QSE::StdAwk::Value arg[2];
+	if (arg[0].setInt (run, -20) <= -1) return -1;
+	if (arg[1].setStr (run, QSE_T("51")) <= -1) return -1;
+
+	// ret = add (-20, 51) 
+	QSE::StdAwk::Value ret;
+	if (awk.call (QSE_T("add"), &ret, arg, 2) <= -1) return -1;
+
+	// ret = mul (ret, 51);
+	arg[0] = ret;
+	if (awk.call (QSE_T("mul"), &ret, arg, 2) <= -1) return -1;
+
+	// ret = div (ret, 2);
+	arg[0] = ret;
+	if (arg[1].setReal (run, 2) <= -1) return -1;
+	if (awk.call (QSE_T("div"), &ret, arg, 2) <= -1) return -1;
+
+	// output the result in various types
+	qse_printf (QSE_T("RESULT: (int) [%lld]\n"), (long long)ret.toInt());
+	qse_printf (QSE_T("        (real) [%Lf]\n"), (long double)ret.toReal());
+	qse_printf (QSE_T("        (str) [%s]\n"), ret.toStr(QSE_NULL));
+
+	return 0;
 }
 
 static int awk_main (int argc, qse_char_t* argv[])
 {
 	QSE::StdAwk awk;
-	QSE::StdAwk::Run* run;
 
-	// initialize awk
-	if (awk.open() <= -1)
-	{
-		print_error (awk.getErrorMessage());
-		return -1;
-	}
+	int ret = awk.open();
 
-	// ARGV[0]
-	if (awk.addArgument (QSE_T("awk05")) <= -1)
-	{
-		print_error (awk.getErrorMessage());
-		awk.close ();
-		return -1;
-	}
-
-	// ARGV[1] and/or the first console input file
-	if (awk.addArgument (QSE_T("awk05.cpp")) <= -1)
-	{
-		print_error (awk.getErrorMessage());
-		awk.close ();
-		return -1;
-	}
-
-	const qse_char_t* script = QSE_T(
-		"BEGIN { print \">> PRINT ALL LINES WHOSE LENGTH IS GREATER THAN 0\"; }\n" 
-		"length($0) > 0 { print $0; count++; }\n"
-		"END { print \">> TOTAL\", count, \"LINES\"; }\n"
-	);
-
-	QSE::StdAwk::SourceString in (script);
-	QSE::StdAwk::SourceFile out (QSE_T("awk05.out"));
-
-	// parse the script string and deparse it to awk05.out.
-	run = awk.parse (&in, &out);
-	if (run == QSE_NULL)
-	{
-		print_error (awk.getErrorLine(), awk.getErrorMessage());
-		awk.close ();
-		return -1;
-	}
-
-	// execute the BEGIN, pattern-action, END blocks.
-	if (awk.loop () <= -1)
-	{
-		print_error (awk.getErrorLine(), awk.getErrorMessage());
-		awk.close ();
-		return -1;
-	}
+	if (ret >= 0) ret = run_awk (awk);
+	if (ret <= -1) print_error (awk.getErrorLine(), awk.getErrorMessage());
 
 	awk.close ();
-	return 0;
+	return -1;
 }
 
 int qse_main (int argc, qse_achar_t* argv[])