diff --git a/qse/doc/Doxyfile b/qse/doc/Doxyfile
index e8074e85..319f04b5 100644
--- a/qse/doc/Doxyfile
+++ b/qse/doc/Doxyfile
@@ -581,7 +581,7 @@ INPUT_ENCODING         = UTF-8
 # *.c *.cc *.cxx *.cpp *.c++ *.java *.ii *.ixx *.ipp *.i++ *.inl *.h *.hh *.hxx 
 # *.hpp *.h++ *.idl *.odl *.cs *.php *.php3 *.inc *.m *.mm *.py *.f90
 
-FILE_PATTERNS          = *.h *.c
+FILE_PATTERNS          = *.h *.c *.hpp *.cpp
 
 # The RECURSIVE tag can be used to turn specify whether or not subdirectories 
 # should be searched for input files as well. Possible values are YES and NO. 
diff --git a/qse/include/qse/Mmgr.hpp b/qse/include/qse/Mmgr.hpp
index 21b5504c..8374fa8f 100644
--- a/qse/include/qse/Mmgr.hpp
+++ b/qse/include/qse/Mmgr.hpp
@@ -26,6 +26,13 @@
 QSE_BEGIN_NAMESPACE(QSE)
 /////////////////////////////////
 
+/**
+ * The Mmgr class defines a memory manager interface that can be inherited
+ * by a class in need of a memory manager as defined in the primitive 
+ * qse_mmgr_t type. Using the class over the primitive type enables you to
+ * write code in more object-oriented fashion. An inheriting class should 
+ * implement three pure virtual functions.
+ */ 
 class Mmgr: public qse_mmgr_t
 {
 public:
@@ -40,20 +47,54 @@ public:
 	virtual ~Mmgr () {}
 
 protected:
-	virtual void* allocMem (qse_size_t n) throw () = 0;
-	virtual void* reallocMem (void* ptr, qse_size_t n) throw () = 0;
-	virtual void  freeMem (void* ptr) throw () = 0;
+	/** 
+	 * The allocMem() function allocates a chunk of memory of the 
+	 * size \a n and return the pointer to the beginning of the chunk.
+	 * If it fails to allocate memory, it should return QSE_NULL.
+	 */
+	virtual void* allocMem (
+		qse_size_t n /**< the size of allocate in bytes */
+	) throw () = 0;
 
+	/**
+	 * The reallocMem() function resizes a chunk of memory previously
+	 * allocated with the allocMem() function. When resized, the contents
+	 * of a surviving memory chunk is left untouched. If it fails to
+	 * resize memory, it should return QSE_NULL.
+	 */
+	virtual void* reallocMem (
+		void* ptr,   /**< a pointer to a memory chunk to resize */
+		qse_size_t n /**< new size in bytes */
+	) throw () = 0;
+
+	/**
+	 * The freeMem() function frees a chunk of memory allocated with
+	 * the allocMem() function or resized with the reallocMem() function.
+	 */
+	virtual void freeMem (
+		void* ptr /**< a pointer to a memory chunk to free */
+	) throw () = 0;
+
+protected:
+	/**
+	 * a bridge function from the qse_mmgr_t type the allocMem() function.
+	 */
 	static void* alloc_mem (void* data, qse_size_t n) throw ()
 	{
 		return ((Mmgr*)data)->allocMem (n);
 	}
 
+	/**
+	 * a bridge function from the qse_mmgr_t type the reallocMem() function.
+	 */
 	static void* realloc_mem (void* data, void* ptr, qse_size_t n) throw ()
 	{
 		return ((Mmgr*)data)->reallocMem (ptr, n);
 	}
 
+	/**
+	 * a bridge function from the qse_mmgr_t type the freeMem() function.
+	 */
 	static void  free_mem (void* data, void* ptr) throw ()
 	{
 		return ((Mmgr*)data)->freeMem (ptr);
diff --git a/qse/include/qse/macros.h b/qse/include/qse/macros.h
index 79bf46f1..4a8851e7 100644
--- a/qse/include/qse/macros.h
+++ b/qse/include/qse/macros.h
@@ -1,5 +1,5 @@
 /*
- * $Id: macros.h 140 2009-05-18 12:55:01Z hyunghwan.chung $
+ * $Id: macros.h 150 2009-05-21 06:17:17Z hyunghwan.chung $
  *
    Copyright 2006-2009 Chung, Hyung-Hwan.
 
@@ -202,13 +202,23 @@
 	qse_mmgr_t* mmgr;
 	
 /**
- * The QSE_DEFINE_COMMON_FUNcTIONS() macro defines common object functions.
+ * The QSE_DEFINE_COMMON_FUNCTIONS() macro defines common object functions.
+ * - @code void qse_xxx_setmmgr (qse_xxx_t* xxx, qse_mmgr_t* mmgr); @endcode
+ *   The qse_xxx_setmmgr() function change the memory manager of a relevant
+ *   object. Take extreme care if you want to use this function.
+ * - @code qse_mmgr_t* qse_xxx_getmmgr (qse_xxx_t* xxx); @endcode
+ *   The qse_xxx_getmmgr() function returns the memory manager of a relevant
+ *   object.
+ * - @code void qse_xxx_getxtn (qse_xxx_t* xxx); @endcode
+ *   The qse_xxx_getxtn() function returns the pointer to an extension area
+ *   of a relevant object created with an extension size greater than 0.
  */
 #define QSE_DEFINE_COMMON_FUNCTIONS(name) \
 void qse_##name##_setmmgr (qse_##name##_t* name, qse_mmgr_t* mmgr); \
 qse_mmgr_t* qse_##name##_getmmgr (qse_##name##_t* name); \
 void* qse_##name##_getxtn (qse_##name##_t* name);
 
+
 /**
  * The QSE_MMGR() macro gets the memory manager field from an object.
  */
diff --git a/qse/include/qse/sed/sed.h b/qse/include/qse/sed/sed.h
index 2a32d2b7..df51eda0 100644
--- a/qse/include/qse/sed/sed.h
+++ b/qse/include/qse/sed/sed.h
@@ -65,7 +65,7 @@ enum qse_sed_errnum_t
 	QSE_SED_ETMTXT,  /**< too much text */
 	QSE_SED_ECMDNR,  /**< a command is not recognized */
 	QSE_SED_ECMDMS,  /**< a command is missing */
-	QSE_SED_ECMDGB,  /**< command garbled */
+	QSE_SED_ECMDIC,  /**< a command is incomplete */
 	QSE_SED_EREXBL,  /**< regular expression build error */
 	QSE_SED_EREXMA,  /**< regular expression match error */
 	QSE_SED_EA1PHB,  /**< address 1 prohibited */
@@ -76,13 +76,11 @@ enum qse_sed_errnum_t
 	QSE_SED_EBSDEL,  /**< \ used a delimiter */
 	QSE_SED_EGBABS,  /**< garbage after \ */
 	QSE_SED_ESCEXP,  /**< ; is expected */
-	QSE_SED_ELABTL,  /**< label too long */
 	QSE_SED_ELABEM,  /**< label name is empty */
 	QSE_SED_ELABDU,  /**< duplicate label name */
 	QSE_SED_ELABNF,  /**< label not found */
 	QSE_SED_EFILEM,  /**< file name is empty */
 	QSE_SED_EFILIL,  /**< illegal file name */
-	QSE_SED_ENOTRM,  /**< not terminated properly */
 	QSE_SED_ETSNSL,  /**< translation set not the same length*/
 	QSE_SED_EGRNBA,  /**< group brackets not balanced */
 	QSE_SED_EGRNTD,  /**< group nested too deeply */
@@ -169,8 +167,15 @@ extern "C" {
 QSE_DEFINE_COMMON_FUNCTIONS (sed)
 
 /**
- * The qse_sed_open() function creates a stream editor.
- * @return A pointer to a stream editor on success, QSE_NULL on a failure
+ * The qse_sed_open() function creates a stream editor object. A memory
+ * manager provided is used to allocate and destory the object and any dynamic
+ * data through out its lifetime. An extension area is allocated if an
+ * extension size greater than 0 is specified. You can access it with the
+ * qse_sed_getxtn() function and use it to store arbitrary data associated
+ * with the object. See #QSE_DEFINE_COMMON_FUNCTIONS() for qse_sed_getxtn().
+ * When done, you should destroy the object with the qse_sed_close() function
+ * to avoid any resource leaks including memory. 
+ * @return A pointer to a stream editor on success, QSE_NULL on failure
  */
 qse_sed_t* qse_sed_open (
 	qse_mmgr_t*    mmgr, /**< a memory manager */
@@ -202,13 +207,54 @@ void qse_sed_setoption (
 );
 
 /**
- * The qse_sed_geterrmsg() function retrieves an error message
- * @return a pointer to a string describing an error occurred 
+ * The qse_sed_geterrnum() function gets the number of the last error.
+ * @return the number of the last error
+ */
+int qse_sed_geterrnum (
+	qse_sed_t* sed /**< a stream editor */
+);
+
+/**
+ * The qse_sed_geterrlin() function gets the number of the line where
+ * the last error has occurred.
+ * @return the line number of the last error
+ */
+qse_size_t qse_sed_geterrlin (
+	qse_sed_t* sed /**< a stream editor */
+);
+
+/**
+ * The qse_sed_geterrmsg() function gets a string describing the last error.
+ * @return a pointer to an error message
  */
 const qse_char_t* qse_sed_geterrmsg (
 	qse_sed_t* sed /**< a stream editor */
 );
 
+/**
+ * The qse_sed_geterror() function gets an error number, an error line, and 
+ * an error message. The information is set to the memory area pointed to by
+ * each parameter.
+ */
+void qse_sed_geterror (
+	qse_sed_t*         sed,    /**< a stream editor */
+	int*               errnum, /**< a pointer to an error number holder */
+	qse_size_t*        errlin, /**< a pointer to an error line holder */
+	const qse_char_t** errmsg  /**< a pointer to an error message */
+);
+
+/**
+ * The qse_sed_seterror() function sets an error number, an error line, and
+ * an error message. An error string is composed of a formatting string
+ * and an array of formatting parameters.
+ */
+void qse_sed_seterror (
+	qse_sed_t*        sed,    /**< a stream editor */
+	int               errnum, /**< an error number */
+	qse_size_t        errlin, /**< an error line */
+	const qse_cstr_t* errarg  /**< a string array for formatting an error message */
+);
+
 /**
  * The qse_sed_comp() function compiles editing commands into an internal form.
  * @return 0 on success, -1 on error 
diff --git a/qse/include/qse/types.h b/qse/include/qse/types.h
index 6665440e..2d9f90bb 100644
--- a/qse/include/qse/types.h
+++ b/qse/include/qse/types.h
@@ -1,5 +1,5 @@
 /*
- * $Id: types.h 127 2009-05-07 13:15:04Z hyunghwan.chung $
+ * $Id: types.h 150 2009-05-21 06:17:17Z hyunghwan.chung $
  *
    Copyright 2006-2009 Chung, Hyung-Hwan.
 
@@ -404,16 +404,37 @@ struct qse_cstr_t
 typedef struct qse_cstr_t qse_cstr_t;
 /******/
 
-/****t* Base/qse_mmgr_t
- * NAME
- *  qse_mmgr_t - define a memory manager
- * SYNOPSIS
+/**
+ * The qse_mmgr_t type defines a set type of functions for memory management.
+ * As the type is merely a structure, it is just used as a single container
+ * for memory management functions with a pointer to user-defined data. 
+ * The user-defined \a data is passed to each memory management function
+ * whenever it is called. You can allocate, reallocate, and free a memory
+ * chunk.
+ *
+ * For example, a qse_xxx_open() function accepts a pointer of the qse_mmgr_t *
+ * type and the xxx object uses it to manage dynamic data within the object. 
  */
 struct qse_mmgr_t
 {
+	/** 
+	 * allocate a memory chunk of the size \a n.
+	 * @return a pointer to a memory chunk on success, QSE_NULL on failure.
+	 */
 	void* (*alloc)   (void* data, qse_size_t n);
+	/** 
+	 * resize a memory chunk pointed to by \a ptr to the size \a n.
+	 * @return a pointer to a memory chunk on success, QSE_NULL on failure.
+	 */
 	void* (*realloc) (void* data, void* ptr, qse_size_t n);
+	/**
+	 * frees a memory chunk pointed to by \a ptr.
+	 */
 	void  (*free)    (void* data, void* ptr);
+	/** 
+	 * a pointer to user-defined data passed as the first parameter to
+	 * alloc(), realloc(), and free().
+	 */
 	void*   data;
 };
 typedef struct qse_mmgr_t qse_mmgr_t;
diff --git a/qse/lib/sed/Makefile.am b/qse/lib/sed/Makefile.am
index 65767728..4ad6f90e 100644
--- a/qse/lib/sed/Makefile.am
+++ b/qse/lib/sed/Makefile.am
@@ -2,7 +2,7 @@
 AM_CPPFLAGS = -I$(top_builddir)/include
 
 lib_LTLIBRARIES = libqsesed.la
-libqsesed_la_SOURCES = sed.c sed.h
+libqsesed_la_SOURCES = sed.c err.c sed.h
 libqsesed_la_LDFLAGS = -version-info 1:0:0 -no-undefined -L../cmn -L../utl
 libqsesed_la_LIBADD = -lqsecmn -lqseutl
 
diff --git a/qse/lib/sed/Makefile.in b/qse/lib/sed/Makefile.in
index 695ef353..e1ddd9e4 100644
--- a/qse/lib/sed/Makefile.in
+++ b/qse/lib/sed/Makefile.in
@@ -60,7 +60,7 @@ libqsesed___la_LINK = $(LIBTOOL) --tag=CXX $(AM_LIBTOOLFLAGS) \
 	$(CXXFLAGS) $(libqsesed___la_LDFLAGS) $(LDFLAGS) -o $@
 @ENABLE_CXX_TRUE@am_libqsesed___la_rpath = -rpath $(libdir)
 libqsesed_la_DEPENDENCIES =
-am_libqsesed_la_OBJECTS = sed.lo
+am_libqsesed_la_OBJECTS = sed.lo err.lo
 libqsesed_la_OBJECTS = $(am_libqsesed_la_OBJECTS)
 libqsesed_la_LINK = $(LIBTOOL) --tag=CC $(AM_LIBTOOLFLAGS) \
 	$(LIBTOOLFLAGS) --mode=link $(CCLD) $(AM_CFLAGS) $(CFLAGS) \
@@ -219,7 +219,7 @@ top_builddir = @top_builddir@
 top_srcdir = @top_srcdir@
 AM_CPPFLAGS = -I$(top_builddir)/include
 lib_LTLIBRARIES = libqsesed.la $(am__append_1)
-libqsesed_la_SOURCES = sed.c sed.h
+libqsesed_la_SOURCES = sed.c err.c sed.h
 libqsesed_la_LDFLAGS = -version-info 1:0:0 -no-undefined -L../cmn -L../utl
 libqsesed_la_LIBADD = -lqsecmn -lqseutl
 @ENABLE_CXX_TRUE@libqsesed___la_SOURCES = Sed.cpp StdSed.cpp
@@ -298,6 +298,7 @@ distclean-compile:
 
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/Sed.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/StdSed.Plo@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/err.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/sed.Plo@am__quote@
 
 .c.o:
diff --git a/qse/lib/sed/err.c b/qse/lib/sed/err.c
new file mode 100644
index 00000000..0380e9a2
--- /dev/null
+++ b/qse/lib/sed/err.c
@@ -0,0 +1,147 @@
+/*
+ * $Id: err.c 113 2009-03-25 14:53:10Z baconevi $
+ *
+   Copyright 2006-2009 Chung, Hyung-Hwan.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+ */
+
+#include "sed.h"
+
+static const qse_char_t* geterrstr (int errnum)
+{
+	static const qse_char_t* errstr[] =
+ 	{
+		QSE_T("no error"),
+		QSE_T("out of memory"),
+		QSE_T("too much text"),
+		QSE_T("command ${0} not recognized"),
+		QSE_T("command code missing"),
+		QSE_T("command ${0} not terminated properly"),
+		QSE_T("regular expression build error"),
+		QSE_T("regular expression match error"),
+		QSE_T("address 1 prohibited"),
+		QSE_T("address 2 prohibited"),
+		QSE_T("invalid step address"),
+		QSE_T("a new line expected"),
+		QSE_T("a backslash expected"),
+		QSE_T("a backslash used as a delimiter"),
+		QSE_T("garbage after a backslash"),
+		QSE_T("a semicolon expected"),
+		QSE_T("empty label name"),
+		QSE_T("duplicate label name ${0}"),
+		QSE_T("label ${0} not found"),
+		QSE_T("empty file name"),
+		QSE_T("illegal file name"),
+		QSE_T("strings in translation set not the same length"),
+		QSE_T("group brackets not balanced"),
+		QSE_T("group nesting too deep"),
+		QSE_T("multiple occurrence specifier"),
+		QSE_T("occurrence specifier is zero"),
+		QSE_T("occurrence specifier too large"),
+		QSE_T("error returned by user io handler")
+	};
+
+	return (errnum >= 0 && errnum < QSE_COUNTOF(errstr))?
+		errstr[errnum]: QSE_T("unknown error");
+}
+
+#if 0
+const qse_char_t* qse_sed_geterrstr (qse_sed_t* sed, qse_sed_errnum_t num)
+{
+	if (sed != QSE_NULL && 
+	    sed->errstr[num] != QSE_NULL) return sed->errstr[num];
+	return geterrstr (num);
+}
+
+int qse_sed_seterrstr (
+	qse_sed_t* sed, qse_sed_errnum_t num, const qse_char_t* str)
+{
+	qse_char_t* dup;
+       
+	if (str == QSE_NULL) dup = QSE_NULL;
+	else
+	{
+		dup = QSE_AWK_STRDUP (sed, str);
+		if (dup == QSE_NULL) return -1;
+	}
+
+	if (sed->errstr[num] != QSE_NULL) 
+		QSE_AWK_FREE (sed, sed->errstr[num]);
+	else sed->errstr[num] = dup;
+	return 0;
+}
+#endif
+
+int qse_sed_geterrnum (qse_sed_t* sed)
+{
+	return sed->errnum;
+}
+
+qse_size_t qse_sed_geterrlin (qse_sed_t* sed)
+{
+	return sed->errlin;
+}
+
+const qse_char_t* qse_sed_geterrmsg (qse_sed_t* sed)
+{
+	if (sed->errmsg[0] == QSE_T('\0')) 
+		/*return qse_sed_geterrstr (sed, sed->errnum);*/
+		return geterrstr (sed->errnum);
+	return sed->errmsg;
+}
+
+void qse_sed_geterror (
+	qse_sed_t* sed, int* errnum, 
+	qse_size_t* errlin, const qse_char_t** errmsg)
+{
+	if (errnum != QSE_NULL) *errnum = sed->errnum;
+	if (errlin != QSE_NULL) *errlin = sed->errlin;
+	if (errmsg != QSE_NULL) 
+	{
+		*errmsg = (sed->errmsg[0] == QSE_T('\0'))?
+			/*qse_sed_geterrstr (sed, sed->errnum):*/
+			geterrstr (sed->errnum):
+			sed->errmsg;
+	}
+}
+
+void qse_sed_seterrnum (qse_sed_t* sed, int errnum)
+{
+	sed->errnum = errnum;
+	sed->errlin = 0;
+	sed->errmsg[0] = QSE_T('\0');
+}
+
+void qse_sed_seterrmsg (qse_sed_t* sed, 
+	int errnum, qse_size_t errlin, const qse_char_t* errmsg)
+{
+	sed->errnum = errnum;
+	sed->errlin = errlin;
+	qse_strxcpy (sed->errmsg, QSE_COUNTOF(sed->errmsg), errmsg);
+}
+
+void qse_sed_seterror (
+	qse_sed_t* sed, int errnum,
+	qse_size_t errlin, const qse_cstr_t* errarg)
+{
+	const qse_char_t* errfmt;
+
+	sed->errnum = errnum;
+	sed->errlin = errlin;
+
+	errfmt = /*qse_sed_geterrstr (sed, errnum);*/ geterrstr (sed->errnum);
+	QSE_ASSERT (errfmt != QSE_NULL);
+	qse_strxfncpy (sed->errmsg, QSE_COUNTOF(sed->errmsg), errfmt, errarg);
+}
+
diff --git a/qse/lib/sed/sed.c b/qse/lib/sed/sed.c
index 363a6a98..9a181530 100644
--- a/qse/lib/sed/sed.c
+++ b/qse/lib/sed/sed.c
@@ -27,6 +27,16 @@ static void free_command (qse_sed_t* sed, qse_sed_cmd_t* cmd);
 static qse_sed_t* qse_sed_init (qse_sed_t* sed, qse_mmgr_t* mmgr);
 static void qse_sed_fini (qse_sed_t* sed);
 
+#define SETERR0(sed,num,line) \
+do { qse_sed_seterror (sed, num, line, QSE_NULL); } while (0)
+
+#define SETERR1(sed,num,line,argp,argl) \
+do { \
+	qse_cstr_t __qse__err__arg__; \
+	__qse__err__arg__.ptr = argp; __qse__err__arg__.len = argl; \
+	qse_sed_seterror (sed, num, line, &__qse__err__arg__); \
+} while (0)
+
 qse_sed_t* qse_sed_open (qse_mmgr_t* mmgr, qse_size_t xtn)
 {
 	qse_sed_t* sed;
@@ -66,14 +76,14 @@ static qse_sed_t* qse_sed_init (qse_sed_t* sed, qse_mmgr_t* mmgr)
 
 	if (qse_str_init (&sed->rexbuf, mmgr, 0) == QSE_NULL)
 	{
-		sed->errnum = QSE_SED_ENOMEM;
+		SETERR0 (sed, QSE_SED_ENOMEM, 0);
 		return QSE_NULL;	
 	}	
 
 	if (qse_map_init (&sed->labs, mmgr, 128, 70) == QSE_NULL)
 	{
 		qse_str_fini (&sed->rexbuf);
-		sed->errnum = QSE_SED_ENOMEM;
+		SETERR0 (sed, QSE_SED_ENOMEM, 0);
 		return QSE_NULL;	
 	}
 	qse_map_setcopier (&sed->labs, QSE_MAP_KEY, QSE_MAP_COPIER_INLINE);
@@ -150,46 +160,6 @@ static void qse_sed_fini (qse_sed_t* sed)
 	qse_str_fini (&sed->rexbuf);
 }
 
-const qse_char_t* qse_sed_geterrmsg (qse_sed_t* sed)
-{
-	static const qse_char_t* errmsg[] =
-	{
-		QSE_T("no error"),
-		QSE_T("out of memory"),
-		QSE_T("too much text"),
-		QSE_T("command not recognized"),
-		QSE_T("command missing"),
-		QSE_T("command garbled"),
-		QSE_T("regular expression build error"),
-		QSE_T("regular expression match error"),
-		QSE_T("address 1 prohibited"),
-		QSE_T("address 2 prohibited"),
-		QSE_T("invalid step address"),
-		QSE_T("a new line expected"),
-		QSE_T("a backslash expected"),
-		QSE_T("a backslash used as a delimiter"),
-		QSE_T("garbage after a backslash"),
-		QSE_T("a semicolon expected"),
-		QSE_T("label name too long"),
-		QSE_T("empty label name"),
-		QSE_T("duplicate label name"),
-		QSE_T("label not found"),
-		QSE_T("empty file name"),
-		QSE_T("illegal file name"),
-		QSE_T("command not terminated properly"),
-		QSE_T("strings in translation set not the same length"),
-		QSE_T("group brackets not balanced"),
-		QSE_T("group nesting too deep"),
-		QSE_T("multiple occurrence specifier"),
-		QSE_T("occurrence specifier is zero"),
-		QSE_T("occurrence specifier too large"),
-		QSE_T("error returned by user io handler")
-	};
-
-	return (sed->errnum > 0 && sed->errnum < QSE_COUNTOF(errmsg))?
-		errmsg[sed->errnum]: QSE_T("unknown error");	
-}
-
 void qse_sed_setoption (qse_sed_t* sed, int option)
 {
 	sed->option = option;
@@ -314,7 +284,7 @@ static void* compile_rex (qse_sed_t* sed, qse_char_t rxend)
 
 		if (qse_str_ccat (&sed->rexbuf, c) == (qse_size_t)-1)
 		{
-			sed->errnum = QSE_SED_ENOMEM;
+			SETERR0 (sed, QSE_SED_ENOMEM, 0);
 			return QSE_NULL;
 		}
 	} 
@@ -405,7 +375,7 @@ static int get_text (qse_sed_t* sed, qse_sed_cmd_t* cmd)
 do { \
 	if (qse_str_ccat (str, c) == (qse_size_t)-1) \
 	{ \
-		sed->errnum = QSE_SED_ENOMEM; \
+		SETERR0 (sed, QSE_SED_ENOMEM, 0); \
 		goto errlabel; \
 	} \
 } while (0)
@@ -497,7 +467,7 @@ static int get_label (qse_sed_t* sed, qse_sed_cmd_t* cmd)
 	t = qse_str_open (sed->mmgr, 0, 32);
 	if (t == QSE_NULL) 
 	{
-		sed->errnum = QSE_SED_ENOMEM;
+		SETERR0 (sed, QSE_SED_ENOMEM, 0);
 		goto oops;
 	}
 
@@ -505,7 +475,7 @@ static int get_label (qse_sed_t* sed, qse_sed_cmd_t* cmd)
 	{
 		if (qse_str_ccat (t, c) == (qse_size_t)-1) 
 		{
-			sed->errnum = QSE_SED_ENOMEM;
+			SETERR0 (sed, QSE_SED_ENOMEM, 0);
 			goto oops;
 		} 
 		c = NXTSC (sed);
@@ -515,15 +485,16 @@ static int get_label (qse_sed_t* sed, qse_sed_cmd_t* cmd)
 	if (qse_map_search (
 		&sed->labs, QSE_STR_PTR(t), QSE_STR_LEN(t)) != QSE_NULL)
 	{
-		sed->errnum = QSE_SED_ELABDU;
+		SETERR1 (sed, QSE_SED_ELABDU, 0, 
+			QSE_STR_PTR(t), QSE_STR_LEN(t));
 		goto oops;
 	}
 
 	if (qse_map_insert (
 		&sed->labs, QSE_STR_PTR(t), QSE_STR_LEN(t), cmd, 0) == QSE_NULL)
 	{
-		sed->errnum = QSE_SED_ENOMEM;
-		goto oops;;
+		SETERR0 (sed, QSE_SED_ENOMEM, 0);
+		goto oops;
 	}
 
 	/* the label can be followed by a command on the same line without 
@@ -581,7 +552,7 @@ static int get_branch_target (qse_sed_t* sed, qse_sed_cmd_t* cmd)
 	t = qse_str_open (sed->mmgr, 0, 32);
 	if (t == QSE_NULL) 
 	{
-		sed->errnum = QSE_SED_ENOMEM;
+		SETERR0 (sed, QSE_SED_ENOMEM, 0);
 		goto oops;
 	}
 
@@ -589,7 +560,7 @@ static int get_branch_target (qse_sed_t* sed, qse_sed_cmd_t* cmd)
 	{
 		if (qse_str_ccat (t, c) == (qse_size_t)-1) 
 		{
-			sed->errnum = QSE_SED_ENOMEM;
+			SETERR0 (sed, QSE_SED_ENOMEM, 0);
 			goto oops;
 		} 
 
@@ -640,7 +611,7 @@ static int get_file (qse_sed_t* sed, qse_xstr_t* xstr)
 	t = qse_str_open (sed->mmgr, 0, 32);
 	if (t == QSE_NULL) 
 	{
-		sed->errnum = QSE_SED_ENOMEM;
+		SETERR0 (sed, QSE_SED_ENOMEM, 0);
 		goto oops;
 	}
 
@@ -672,7 +643,7 @@ static int get_file (qse_sed_t* sed, qse_xstr_t* xstr)
 
 		if (qse_str_ccat (t, c) == (qse_size_t)-1) 
 		{
-			sed->errnum = QSE_SED_ENOMEM;
+			SETERR0 (sed, QSE_SED_ENOMEM, 0);
 			goto oops;
 		} 
 
@@ -706,7 +677,7 @@ static int get_subst (qse_sed_t* sed, qse_sed_cmd_t* cmd)
 	if (c == QSE_CHAR_EOF || IS_LINTERM(c))
 	{
 		/* not terminated properly */
-		sed->errnum = QSE_SED_ENOTRM;
+		SETERR1 (sed, QSE_SED_ECMDIC, 0, &cmd->type, 1);
 		goto oops;
 	}
 
@@ -723,7 +694,7 @@ static int get_subst (qse_sed_t* sed, qse_sed_cmd_t* cmd)
 		t[i] = qse_str_open (sed->mmgr, 0, 32);
 		if (t[i] == QSE_NULL) 
 		{
-			sed->errnum = QSE_SED_ENOMEM;
+			SETERR0 (sed, QSE_SED_ENOMEM, 0);
 			goto oops;
 		}
 	}
@@ -737,7 +708,7 @@ static int get_subst (qse_sed_t* sed, qse_sed_cmd_t* cmd)
 		{
 			if (c == QSE_CHAR_EOF || IS_LINTERM(c))
 			{
-				sed->errnum = QSE_SED_ENOTRM;
+				SETERR1 (sed, QSE_SED_ECMDIC, 0, &cmd->type, 1);
 				goto oops;
 			}
 
@@ -746,7 +717,7 @@ static int get_subst (qse_sed_t* sed, qse_sed_cmd_t* cmd)
 				c = NXTSC (sed);
 				if (c == QSE_CHAR_EOF || IS_LINTERM(c))
 				{
-					sed->errnum = QSE_SED_ENOTRM;
+					SETERR1 (sed, QSE_SED_ECMDIC, 0, &cmd->type, 1);
 					goto oops;
 				}
 	
@@ -755,7 +726,7 @@ static int get_subst (qse_sed_t* sed, qse_sed_cmd_t* cmd)
 
 			if (qse_str_ccat (t[i], c) == (qse_size_t)-1)
 			{
-				sed->errnum = QSE_SED_ENOMEM;
+				SETERR0 (sed, QSE_SED_ENOMEM, 0);
 				goto oops;
 			}
 
@@ -868,7 +839,7 @@ static int get_transet (qse_sed_t* sed, qse_sed_cmd_t* cmd)
 	if (c == QSE_CHAR_EOF || IS_LINTERM(c))
 	{
 		/* translation set terminated prematurely*/
-		sed->errnum = QSE_SED_ENOTRM;
+		SETERR1 (sed, QSE_SED_ECMDIC, 0, &cmd->type, 1);
 		goto oops;
 	}
 
@@ -883,7 +854,7 @@ static int get_transet (qse_sed_t* sed, qse_sed_cmd_t* cmd)
 	t = qse_str_open (sed->mmgr, 0, 32);
 	if (t == QSE_NULL) 
 	{
-		sed->errnum = QSE_SED_ENOMEM;
+		SETERR0 (sed, QSE_SED_ENOMEM, 0);
 		goto oops;
 	}
 
@@ -894,7 +865,7 @@ static int get_transet (qse_sed_t* sed, qse_sed_cmd_t* cmd)
 
 		if (c == QSE_CHAR_EOF || IS_LINTERM(c))
 		{
-			sed->errnum = QSE_SED_ENOTRM;
+			SETERR1 (sed, QSE_SED_ECMDIC, 0, &cmd->type, 1);
 			goto oops;
 		}
 
@@ -903,7 +874,7 @@ static int get_transet (qse_sed_t* sed, qse_sed_cmd_t* cmd)
 			c = NXTSC (sed);
 			if (c == QSE_CHAR_EOF || IS_LINTERM(c))
 			{
-				sed->errnum = QSE_SED_ENOTRM;
+				SETERR1 (sed, QSE_SED_ECMDIC, 0, &cmd->type, 1);
 				goto oops;
 			}
 
@@ -913,7 +884,7 @@ static int get_transet (qse_sed_t* sed, qse_sed_cmd_t* cmd)
 		b[0] = c;
 		if (qse_str_ncat (t, b, 2) == (qse_size_t)-1)
 		{
-			sed->errnum = QSE_SED_ENOMEM;
+			SETERR0 (sed, QSE_SED_ENOMEM, 0);
 			goto oops;
 		}
 
@@ -925,7 +896,7 @@ static int get_transet (qse_sed_t* sed, qse_sed_cmd_t* cmd)
 	{
 		if (c == QSE_CHAR_EOF || IS_LINTERM(c))
 		{
-			sed->errnum = QSE_SED_ENOTRM;
+			SETERR1 (sed, QSE_SED_ECMDIC, 0, &cmd->type, 1);
 			goto oops;
 		}
 
@@ -934,7 +905,7 @@ static int get_transet (qse_sed_t* sed, qse_sed_cmd_t* cmd)
 			c = NXTSC (sed);
 			if (c == QSE_CHAR_EOF || IS_LINTERM(c))
 			{
-				sed->errnum = QSE_SED_ENOTRM;
+				SETERR1 (sed, QSE_SED_ECMDIC, 0, &cmd->type, 1);
 				goto oops;
 			}
 
@@ -981,11 +952,14 @@ restart:
 	switch (c)
 	{
 		default:
-			sed->errnum = QSE_SED_ECMDNR;
+		{
+			qse_char_t cc = c;
+			SETERR1 (sed, QSE_SED_ECMDNR, 0, &cc, 1);
 			return -1;
+		}
 
 		case QSE_CHAR_EOF:
-			sed->errnum = QSE_SED_ECMDMS;
+			SETERR0 (sed, QSE_SED_ECMDMS, 0);
 			return -1;	
 
 		case QSE_T(':'):
@@ -1264,7 +1238,7 @@ static int compile_source (
 			{
 				/* TODO: too many commands. change errnum */
 				free_command (sed, cmd);
-				sed->errnum = QSE_SED_ENOMEM; 
+				SETERR0 (sed, QSE_SED_ENOMEM, 0); 
 				return -1;
 			}
 
@@ -1372,7 +1346,7 @@ static int read_file (qse_sed_t* sed, const qse_char_t* path, int line)
 				if (qse_str_ccat (&sed->e.txt.read, buf[i]) == (qse_size_t)-1)
 				{
 					sed->e.in.fun (sed, QSE_SED_IO_CLOSE, &arg);
-					sed->errnum = QSE_SED_ENOMEM;
+					SETERR0 (sed, QSE_SED_ENOMEM, 0);
 					return -1;
 				}
 
@@ -1385,7 +1359,7 @@ static int read_file (qse_sed_t* sed, const qse_char_t* path, int line)
 			if (qse_str_ncat (&sed->e.txt.read, buf, n) == (qse_size_t)-1)
 			{
 				sed->e.in.fun (sed, QSE_SED_IO_CLOSE, &arg);
-				sed->errnum = QSE_SED_ENOMEM;
+				SETERR0 (sed, QSE_SED_ENOMEM, 0);
 				return -1;
 			}
 		}
@@ -1429,7 +1403,7 @@ static int read_line (qse_sed_t* sed, int append)
 
 		if (qse_str_ccat (&sed->e.in.line, c) == (qse_size_t)-1)
 		{
-			sed->errnum = QSE_SED_ENOMEM;
+			SETERR0 (sed, QSE_SED_ENOMEM, 0);
 			return -1;
 		}
 		len++;	
@@ -1653,7 +1627,7 @@ static int write_str_to_file (
 			path, plen, &arg, QSE_SIZEOF(arg));
 		if (pair == QSE_NULL)
 		{
-			sed->errnum = QSE_SED_ENOMEM;
+			SETERR0 (sed, QSE_SED_ENOMEM, 0);
 			return -1;
 		}
 	}
@@ -1761,7 +1735,7 @@ static int do_subst (qse_sed_t* sed, qse_sed_cmd_t* cmd)
 				&sed->e.txt.subst,
 				cur_ptr, cur_len) == (qse_size_t)-1)
 			{
-				sed->errnum = QSE_SED_ENOMEM;
+				SETERR0 (sed, QSE_SED_ENOMEM, 0);
 				return -1;
 			}
 			break;
@@ -1776,7 +1750,7 @@ static int do_subst (qse_sed_t* sed, qse_sed_cmd_t* cmd)
 
 			if (m == (qse_size_t)-1)
 			{
-				sed->errnum = QSE_SED_ENOMEM;
+				SETERR0 (sed, QSE_SED_ENOMEM, 0);
 				return -1;
 			}
 		}
@@ -1788,7 +1762,7 @@ static int do_subst (qse_sed_t* sed, qse_sed_cmd_t* cmd)
 				&sed->e.txt.subst, cur_ptr, mat.ptr-cur_ptr);
 			if (m == (qse_size_t)-1)
 			{
-				sed->errnum = QSE_SED_ENOMEM;
+				SETERR0 (sed, QSE_SED_ENOMEM, 0);
 				return -1;
 			}
 
@@ -1817,7 +1791,7 @@ static int do_subst (qse_sed_t* sed, qse_sed_cmd_t* cmd)
 
 				if (m == (qse_size_t)-1)
 				{
-					sed->errnum = QSE_SED_ENOMEM;
+					SETERR0 (sed, QSE_SED_ENOMEM, 0);
 					return -1;
 				}
 			}
@@ -1834,7 +1808,7 @@ static int do_subst (qse_sed_t* sed, qse_sed_cmd_t* cmd)
 		m = qse_str_ccat (&sed->e.txt.subst, QSE_T('\n'));
 		if (m == (qse_size_t)-1)
 		{
-			sed->errnum = QSE_SED_ENOMEM;
+			SETERR0 (sed, QSE_SED_ENOMEM, 0);
 			return -1;
 		}
 	}
@@ -2053,7 +2027,7 @@ static qse_sed_cmd_t* exec_cmd (qse_sed_t* sed, qse_sed_cmd_t* cmd)
 				QSE_LDA_SIZE(&sed->e.txt.appended),	
 				&cmd->u.text, 0) == (qse_size_t)-1) 
 			{
-				sed->errnum = QSE_SED_ENOMEM;
+				SETERR0 (sed, QSE_SED_ENOMEM, 0);
 				return QSE_NULL;
 			}
 			break;
@@ -2075,7 +2049,7 @@ static qse_sed_cmd_t* exec_cmd (qse_sed_t* sed, qse_sed_cmd_t* cmd)
 					QSE_STR_LEN(&cmd->u.text));
 				if (n == (qse_size_t)-1) 
 				{
-					sed->errnum = QSE_SED_ENOMEM;
+					SETERR0 (sed, QSE_SED_ENOMEM, 0);
 					return QSE_NULL;
 				}
 			}
@@ -2167,7 +2141,7 @@ static qse_sed_cmd_t* exec_cmd (qse_sed_t* sed, qse_sed_cmd_t* cmd)
 				QSE_STR_PTR(&sed->e.in.line),
 				QSE_STR_LEN(&sed->e.in.line)) == (qse_size_t)-1)
 			{
-				sed->errnum = QSE_SED_ENOMEM;
+				SETERR0 (sed, QSE_SED_ENOMEM, 0);
 				return QSE_NULL;	
 			}
 			break;
@@ -2178,7 +2152,7 @@ static qse_sed_cmd_t* exec_cmd (qse_sed_t* sed, qse_sed_cmd_t* cmd)
 				QSE_STR_PTR(&sed->e.in.line),
 				QSE_STR_LEN(&sed->e.in.line)) == (qse_size_t)-1)
 			{
-				sed->errnum = QSE_SED_ENOMEM;
+				SETERR0 (sed, QSE_SED_ENOMEM, 0);
 				return QSE_NULL;	
 			}
 			break;
@@ -2189,7 +2163,7 @@ static qse_sed_cmd_t* exec_cmd (qse_sed_t* sed, qse_sed_cmd_t* cmd)
 				QSE_STR_PTR(&sed->e.txt.held),
 				QSE_STR_LEN(&sed->e.txt.held)) == (qse_size_t)-1)
 			{
-				sed->errnum = QSE_SED_ENOMEM;
+				SETERR0 (sed, QSE_SED_ENOMEM, 0);
 				return QSE_NULL;	
 			}
 			break;
@@ -2200,7 +2174,7 @@ static qse_sed_cmd_t* exec_cmd (qse_sed_t* sed, qse_sed_cmd_t* cmd)
 				QSE_STR_PTR(&sed->e.txt.held),
 				QSE_STR_LEN(&sed->e.txt.held)) == (qse_size_t)-1)
 			{
-				sed->errnum = QSE_SED_ENOMEM;
+				SETERR0 (sed, QSE_SED_ENOMEM, 0);
 				return QSE_NULL;	
 			}
 			break;
@@ -2308,7 +2282,10 @@ static qse_sed_cmd_t* exec_cmd (qse_sed_t* sed, qse_sed_cmd_t* cmd)
 						&sed->labs, lab->ptr, lab->len);
 					if (pair == QSE_NULL)
 					{
-						sed->errnum = QSE_SED_ELABNF;
+						SETERR1 (
+							sed, QSE_SED_ELABNF, 0,
+							lab->ptr, lab->len
+						);
 						return QSE_NULL;
 					}
 
@@ -2384,7 +2361,7 @@ int qse_sed_exec (qse_sed_t* sed, qse_sed_io_fun_t inf, qse_sed_io_fun_t outf)
 	qse_str_clear (&sed->e.txt.held);
 	if (qse_str_ccat (&sed->e.txt.held, QSE_T('\n')) == (qse_size_t)-1)
 	{
-		sed->errnum = QSE_SED_ENOMEM;
+		SETERR0 (sed, QSE_SED_ENOMEM, 0);
 		return -1;
 	}
 
@@ -2393,7 +2370,7 @@ int qse_sed_exec (qse_sed_t* sed, qse_sed_io_fun_t inf, qse_sed_io_fun_t outf)
 	sed->e.out.len = 0;
 	if (qse_map_init (&sed->e.out.files, sed->mmgr, 128, 70) == QSE_NULL)
 	{
-		sed->errnum = QSE_SED_ENOMEM;
+		SETERR0 (sed, QSE_SED_ENOMEM, 0);
 		return -1;
 	}
 	*(qse_sed_t**)QSE_XTN(&sed->e.out.files) = sed;
@@ -2414,7 +2391,7 @@ int qse_sed_exec (qse_sed_t* sed, qse_sed_io_fun_t inf, qse_sed_io_fun_t outf)
 	if (qse_str_init (&sed->e.in.line, QSE_MMGR(sed), 256) == QSE_NULL)
 	{
 		qse_map_fini (&sed->e.out.files);
-		sed->errnum = QSE_SED_ENOMEM;
+		SETERR0 (sed, QSE_SED_ENOMEM, 0);
 		return -1;
 	}
 
diff --git a/qse/lib/sed/sed.h b/qse/lib/sed/sed.h
index d49c3e6a..86fd2f8e 100644
--- a/qse/lib/sed/sed.h
+++ b/qse/lib/sed/sed.h
@@ -34,6 +34,9 @@ struct qse_sed_t
 	QSE_DEFINE_COMMON_FIELDS (sed)
 
 	qse_sed_errnum_t errnum; /**< stores an error number */
+	qse_char_t errmsg[128];  /**< error message holder */
+	qse_size_t errlin;       /**< no of the line where an error occurred */
+
 	int option;              /**< stores options */
 
 	/** source text pointers */
@@ -139,46 +142,36 @@ struct qse_sed_adr_t
 	} u;
 };
 
+#define QSE_SED_CMD_QUIT            QSE_T('q')
+#define QSE_SED_CMD_QUIT_QUIET      QSE_T('Q')
+#define QSE_SED_CMD_APPEND          QSE_T('a')
+#define QSE_SED_CMD_INSERT          QSE_T('i')
+#define QSE_SED_CMD_CHANGE          QSE_T('c')
+#define QSE_SED_CMD_DELETE          QSE_T('d')
+#define QSE_SED_CMD_DELETE_FIRSTLN  QSE_T('D')
+#define QSE_SED_CMD_PRINT_LNNUM     QSE_T('=')
+#define QSE_SED_CMD_PRINT           QSE_T('p')
+#define QSE_SED_CMD_PRINT_FIRSTLN   QSE_T('P')
+#define QSE_SED_CMD_PRINT_CLEARLY   QSE_T('l')
+#define QSE_SED_CMD_HOLD            QSE_T('h')
+#define QSE_SED_CMD_HOLD_APPEND     QSE_T('H')
+#define QSE_SED_CMD_RELEASE         QSE_T('g')
+#define QSE_SED_CMD_RELEASE_APPEND  QSE_T('G')
+#define QSE_SED_CMD_EXCHANGE        QSE_T('x') 
+#define QSE_SED_CMD_NEXT            QSE_T('n')
+#define QSE_SED_CMD_NEXT_APPEND     QSE_T('N')
+#define QSE_SED_CMD_READ_FILE       QSE_T('r')
+#define QSE_SED_CMD_READ_FILELN     QSE_T('R')
+#define QSE_SED_CMD_WRITE_FILE      QSE_T('w')
+#define QSE_SED_CMD_WRITE_FILELN    QSE_T('W')
+#define QSE_SED_CMD_BRANCH          QSE_T('b') 
+#define QSE_SED_CMD_BRANCH_COND     QSE_T('t')
+#define QSE_SED_CMD_SUBSTITUTE      QSE_T('s')
+#define QSE_SED_CMD_TRANSLATE       QSE_T('y')
+
 struct qse_sed_cmd_t
 {
-	enum
-	{
-		QSE_SED_CMD_QUIT           = QSE_T('q'),
-		QSE_SED_CMD_QUIT_QUIET     = QSE_T('Q'),
-
-		QSE_SED_CMD_APPEND         = QSE_T('a'),
-		QSE_SED_CMD_INSERT         = QSE_T('i'),
-		QSE_SED_CMD_CHANGE         = QSE_T('c'),
-
-		QSE_SED_CMD_DELETE         = QSE_T('d'),
-		QSE_SED_CMD_DELETE_FIRSTLN = QSE_T('D'),
-
-		QSE_SED_CMD_PRINT_LNNUM    = QSE_T('='),
-		QSE_SED_CMD_PRINT          = QSE_T('p'),
-		QSE_SED_CMD_PRINT_FIRSTLN  = QSE_T('P'),
-		QSE_SED_CMD_PRINT_CLEARLY  = QSE_T('l'),
-
-		QSE_SED_CMD_HOLD           = QSE_T('h'),
-		QSE_SED_CMD_HOLD_APPEND    = QSE_T('H'),
-		QSE_SED_CMD_RELEASE        = QSE_T('g'),
-		QSE_SED_CMD_RELEASE_APPEND = QSE_T('G'),
-		QSE_SED_CMD_EXCHANGE       = QSE_T('x'), 
-
-		QSE_SED_CMD_NEXT           = QSE_T('n'),
-		QSE_SED_CMD_NEXT_APPEND    = QSE_T('N'),
-
-		QSE_SED_CMD_READ_FILE      = QSE_T('r'),
-		QSE_SED_CMD_READ_FILELN    = QSE_T('R'),
-		QSE_SED_CMD_WRITE_FILE     = QSE_T('w'),
-		QSE_SED_CMD_WRITE_FILELN   = QSE_T('W'),
-
-		QSE_SED_CMD_BRANCH         = QSE_T('b'), 
-		QSE_SED_CMD_BRANCH_COND    = QSE_T('t'),
-
-		QSE_SED_CMD_SUBSTITUTE     = QSE_T('s'),
-		QSE_SED_CMD_TRANSLATE      = QSE_T('y')
-
-	} type;
+	qse_char_t type;
 
 	int negated;