diff --git a/data/languages/c/highlight.xml b/data/languages/c/highlight.xml
index 941f4fc..98d63ef 100644
--- a/data/languages/c/highlight.xml
+++ b/data/languages/c/highlight.xml
@@ -12,39 +12,39 @@
 	<pass1><!-- multiline section & parse all file (now) and when modification retrive previous modification -->
 		<rule name="my comment multiline doxygen">
 			<color>commentDoxygen</color>
-			<regex>/\*\*.*(\*/|\e)</regex>
+			<regex>/\*\*(.|\r|\n)*?\*/</regex>
 		</rule>
 		<rule name="code Review">
 			<color>SYNTAX_ERROR</color>
-			<regex>/\*[ \t]*TODO :.*(\*/|\e)</regex>
+			<regex>/\*[ \t]*TODO :(.|\r|\n)*?\*/</regex>
 		</rule>
 		<rule name="my comment multiline">
 			<color>comment</color>
-			<regex>/\*.*(\*/|\e)</regex>
+			<regex>/\*(.|\r|\n)*?\*/</regex>
 		</rule>
 		<rule name="my if 0">
 			<color>preprocesseur</color>
-			<regex>#[ \t]*if 0.*#(endif|else)</regex>
+			<regex>#[ \t]*if 0(.|\r|\n)*?#(endif|else)</regex>
 		</rule>
 		<rule name="my preprocesseur">
 			<color>preprocesseur</color>
-			<regex>#(\\[\\\n]|.)*$</regex>
+			<regex>#(\\[\\\n]|.)*</regex>
 		</rule>
 		<rule name="my comment doxygen">
 			<color>commentDoxygen</color>
-			<regex>//!.*$</regex>
+			<regex>//!.*</regex>
 		</rule>
 		<rule name="my todo comment">
 			<color>SYNTAX_ERROR</color>
-			<regex>//[ \t]*TODO[ \t]*:.*$</regex>
+			<regex>//[ \t]*TODO[ \t]*:.*</regex>
 		</rule>
 		<rule name="my comment">
 			<color>comment</color>
-			<regex>//.*$</regex>
+			<regex>//.*</regex>
 		</rule>
 		<rule name="doubleQuteText">
 			<color>doubleQuoteText</color>
-			<regex>"(\\[\\"]|.)*"</regex><!-- " -->
+			<regex>"(\\[\\"]|.)*"</regex>
 		</rule>
 		<rule name="simpleQuteText">
 			<color>doubleQuoteText</color>
@@ -106,17 +106,15 @@
 			<color>functionName</color>
 			<regex>\@(\w|_)+[ \t]*\(</regex>
 		</rule>
-		-->
 		<rule name="condition">
 			<color>boolean</color>
 			<regex>==|&lt;=|&gt;=|!=|&lt;{1,2}|&gt;{1,2}|&amp;&amp;|\{|\}|</regex>
 		</rule>
-		<!-- With all elementes : 
+		-->
 		<rule name="BIG LETTER">
 			<color>macro</color>
 			<regex>([A-Z]|_){4,500}</regex>
 			<elemSubColor id="1">doxElem</elemSubColor>
 		</rule>
-		-->
 	</pass2>
 </EdnLang>
diff --git a/sources/appl/Buffer.cpp b/sources/appl/Buffer.cpp
index 08656d0..63ef63d 100644
--- a/sources/appl/Buffer.cpp
+++ b/sources/appl/Buffer.cpp
@@ -17,33 +17,101 @@
 #undef __class__
 #define __class__ "Buffer"
 
+appl::Buffer::Iterator& appl::Buffer::Iterator::operator++ () {
+	m_value = u32char::Null;
+	if (m_current < 0) {
+		m_current = 0;
+		return *this;
+	}
+	if (m_data != nullptr) {
+		if (m_current < (int64_t)m_data->m_data.size() ) {
+			int8_t nbChar = utf8::theoricLen(m_data->m_data[m_current]);
+			if (nbChar != 0) {
+				m_current+=nbChar;
+			} else {
+				m_current++;
+			}
+		}
+		if (m_current >= (int64_t)m_data->m_data.size()) {
+			m_current = m_data->m_data.size();
+		}
+	}
+	return *this;
+}
+
+appl::Buffer::Iterator& appl::Buffer::Iterator::operator-- () {
+	m_value = u32char::Null;
+	if (m_data != nullptr) {
+		if (m_current > 0) {
+			int32_t iii = -1;
+			while(    utf8::theoricFirst(m_data->m_data[m_current+iii]) == false
+			       && iii >= -6
+			       && m_current-iii>0) {
+				--iii;
+			};
+			m_current += iii;
+		} else {
+			m_current = -1;
+		}
+		return *this;
+	} else {
+		m_current = -1;
+	}
+	return *this;
+}
+
+char32_t appl::Buffer::Iterator::operator* () {
+	if (m_value != u32char::Null) {
+		return m_value;
+	}
+	if (m_data == nullptr) {
+		APPL_ERROR("request an element that iterator not link");
+		return m_value;
+	}
+	if (    m_current < 0
+	     || m_current >= (int64_t)m_data->m_data.size()) {
+		APPL_ERROR("request an element out of bounding !!! 0 <= " << m_current << " < " << m_data->m_data.size());
+		return m_value;
+	}
+	char tmpVal[5];
+	memset(tmpVal, 0, sizeof(tmpVal));
+	tmpVal[0] = m_data->m_data[m_current];
+	int8_t nbChar = utf8::theoricLen(tmpVal[0]);
+	for (int32_t iii=1; iii<nbChar && m_current+iii<(int64_t)m_data->m_data.size(); ++iii) {
+		tmpVal[iii] = m_data->m_data[m_current+iii];
+	}
+	// transform ...
+	m_value = utf8::convertChar32(tmpVal);
+	return m_value;
+}
+
 
 appl::Buffer::Iterator appl::Buffer::position(int64_t _pos) {
-	return m_data.begin() + _pos;
+	return appl::Buffer::Iterator(this, _pos);
 }
 
 appl::Buffer::Iterator appl::Buffer::begin() {
-	return m_data.begin();
+	return position(0);
 }
 
 appl::Buffer::Iterator appl::Buffer::end() {
 	// TODO : chek the validity of the char ...
-	return m_data.end();
+	return position( m_data.size() );
 }
 
 appl::Buffer::Iterator appl::Buffer::cursor() {
 	if (m_cursorPos<= 0) {
-		return m_data.begin();
+		return begin();
 	}
-	return m_data.begin() + m_cursorPos;
+	return position( m_cursorPos );
 }
 
 appl::Buffer::Iterator appl::Buffer::selectStart() {
-	return m_data.begin() + getStartSelectionPos();
+	return position( getStartSelectionPos() );
 }
 
 appl::Buffer::Iterator appl::Buffer::selectStop() {
-	return m_data.begin() + getStopSelectionPos();
+	return position( getStopSelectionPos() );
 }
 
 appl::Buffer::Buffer() :
@@ -84,15 +152,20 @@ bool appl::Buffer::loadFile(const std::string& _name) {
 	m_cursorPos = 0;
 	setHighlightType("");
 	m_nbLines = 0;
-	etk::FSNode filee(m_fileName);
-	if (filee.exist() == true) {
-		m_data = file.fileReadAllU32String();
-		countNumberofLine();
-		tryFindHighlightType();
-		m_isModify = false;
-		return true;
+	if (file.exist() == false) {
+		APPL_ERROR("File : '" << m_fileName << "' does not exist...");
+		return false;
 	}
-	return false;
+	if (file.fileOpenRead() == false) {
+		APPL_ERROR("File : '" << m_fileName << "' Fail to open in read mode");
+		return false;
+	}
+	m_data = file.fileReadAllString();
+	file.fileClose();
+	countNumberofLine();
+	tryFindHighlightType();
+	m_isModify = false;
+	return true;
 }
 
 void appl::Buffer::setFileName(const std::string& _name) {
@@ -109,8 +182,13 @@ void appl::Buffer::setFileName(const std::string& _name) {
 }
 
 bool appl::Buffer::storeFile() {
-	etk::FSNode filee(m_fileName);
-	filee.fileWriteAll(m_data);
+	etk::FSNode file(m_fileName);
+	if (file.fileOpenWrite() == false) {
+		APPL_ERROR("File : '" << m_fileName << "' Fail to open in write mode");
+		return false;
+	}
+	file.fileWriteAll(m_data);
+	file.fileClose();
 	APPL_INFO("saving file : " << m_fileName);
 	setModification(false);
 	return true;
@@ -131,8 +209,10 @@ void appl::Buffer::setModification(bool _status) {
 // TODO : Naming error
 void appl::Buffer::countNumberofLine() {
 	m_nbLines = 1;
-	for (auto &it : m_data) {
-		if (it == u32char::Return) {
+	for (Iterator it = begin();
+	     (bool)it == true;
+	     ++it) {
+		if (*it == u32char::Return) {
 			++m_nbLines;
 		}
 	}
@@ -161,21 +241,21 @@ appl::Buffer::Iterator appl::Buffer::getEndLine(const appl::Buffer::Iterator& _p
 bool appl::Buffer::search(const appl::Buffer::Iterator& _pos, const char32_t& _search, appl::Buffer::Iterator& _result) {
 	// move in the string
 	for (Iterator it = _pos;
-	     it != m_data.end();
+	     (bool)it == true;
 	     ++it) {
 		if (*it == _search) {
 			_result = it;
 			return true;
 		}
 	}
-	_result = m_data.end();
+	_result = end();
 	return false;
 }
 
 bool appl::Buffer::searchBack(const appl::Buffer::Iterator& _pos, const char32_t& _search, appl::Buffer::Iterator& _result) {
 	// move in the string
 	for (Iterator it = _pos - 1;
-	     it != m_data.begin();
+	     (bool)it == true;
 	     --it) {
 		//APPL_DEBUG("compare : " << *it << " ?= " << _search);
 		if (*it == _search) {
@@ -198,7 +278,7 @@ bool appl::Buffer::search(const appl::Buffer::Iterator& _pos,
 	if (_caseSensitive == true) {
 		// move in the string
 		for (Iterator it = _pos;
-		     it == m_data.end();
+		     (bool)it == true;
 		     ++it) {
 			if (*it == _search[0]) {
 				// find the first char ==> check next...
@@ -210,7 +290,7 @@ bool appl::Buffer::search(const appl::Buffer::Iterator& _pos,
 						break;
 					}
 					++tmp;
-					if (tmp == m_data.end()) {
+					if ((bool)tmp == false) {
 						if (iii != _search.size()-1) {
 							find = false;
 						}
@@ -227,7 +307,7 @@ bool appl::Buffer::search(const appl::Buffer::Iterator& _pos,
 		char32_t firstElement = tolower(_search[0]);
 		// move in the string
 		for (Iterator it = _pos;
-		     it == m_data.end();
+		     (bool)it == true;
 		     ++it) {
 			if ((char32_t)tolower(*it) == firstElement) {
 				// find the first char ==> check next...
@@ -239,7 +319,7 @@ bool appl::Buffer::search(const appl::Buffer::Iterator& _pos,
 						break;
 					}
 					++tmp;
-					if (tmp != m_data.end()) {
+					if ((bool)tmp == false) {
 						if (iii != _search.size()-1) {
 							find = false;
 						}
@@ -268,7 +348,7 @@ bool appl::Buffer::searchBack(const appl::Buffer::Iterator& _pos,
 	if (_caseSensitive == true) {
 		// move in the string
 		for (Iterator it = _pos - 1;
-		     it != m_data.begin();
+		     (bool)it == true;
 		     --it) {
 			//APPL_DEBUG("compare : " << *it << " ?= " << _search);
 			if (*it == lastElement) {
@@ -281,7 +361,7 @@ bool appl::Buffer::searchBack(const appl::Buffer::Iterator& _pos,
 						break;
 					}
 					--_result;
-					if (_result == m_data.begin()) {
+					if ((bool)_result == false) {
 						if (iii != 0) {
 							find = false;
 						}
@@ -298,7 +378,7 @@ bool appl::Buffer::searchBack(const appl::Buffer::Iterator& _pos,
 		lastElement = tolower(lastElement);
 		// move in the string
 		for (Iterator it = _pos - 1;
-		     it != m_data.begin();
+		     (bool)it == true;
 		     --it) {
 			//APPL_DEBUG("compare : " << *it << " ?= " << _search);
 			if ((char32_t)tolower(*it) == lastElement) {
@@ -311,7 +391,7 @@ bool appl::Buffer::searchBack(const appl::Buffer::Iterator& _pos,
 						break;
 					}
 					--_result;
-					if (_result == m_data.begin()) {
+					if ((bool)_result == false) {
 						if (iii != 0) {
 							find = false;
 						}
@@ -357,15 +437,15 @@ void appl::Buffer::moveCursor(int64_t _pos) {
 bool appl::Buffer::getPosAround(const appl::Buffer::Iterator& _startPos,
                                 appl::Buffer::Iterator &_beginPos,
                                 appl::Buffer::Iterator &_endPos) {
-	char32_t currentValue = *_startPos;
+	char32_t currentValue = *position(_startPos);
 	_beginPos = begin();
 	_endPos = end();
 	if (    currentValue == u32char::Tabulation
 	     || currentValue == u32char::Space) {
 		APPL_DEBUG("select spacer");
 		// Search back
-		for (Iterator it = --Iterator(_startPos);
-		     it != m_data.begin();
+		for (Iterator it = --position(_startPos);
+		     (bool)it == true;
 		     --it) {
 			currentValue = *it;
 			if (    currentValue != u32char::Tabulation
@@ -375,8 +455,8 @@ bool appl::Buffer::getPosAround(const appl::Buffer::Iterator& _startPos,
 			}
 		}
 		// Search forward
-		for (Iterator it = _startPos;
-		     it != m_data.end();
+		for (Iterator it = position(_startPos);
+		     (bool)it == true;
 		     ++it) {
 			currentValue = *it;
 			if (    currentValue != u32char::Tabulation
@@ -390,8 +470,8 @@ bool appl::Buffer::getPosAround(const appl::Buffer::Iterator& _startPos,
 	           || currentValue == '_') {
 		APPL_DEBUG("select normal Char");
 		// Search back
-		for (Iterator it = --Iterator(_startPos);
-		     it == m_data.begin();
+		for (Iterator it = --position(_startPos);
+		     (bool)it == true;
 		     --it) {
 			currentValue = *it;
 			if (    currentValue != '_'
@@ -401,8 +481,8 @@ bool appl::Buffer::getPosAround(const appl::Buffer::Iterator& _startPos,
 			}
 		}
 		// Search forward
-		for (Iterator it = _startPos;
-		     it != m_data.end();
+		for (Iterator it = position(_startPos);
+		     (bool)it == true;
 		     ++it) {
 			currentValue = *it;
 			if (    currentValue != '_'
@@ -416,8 +496,8 @@ bool appl::Buffer::getPosAround(const appl::Buffer::Iterator& _startPos,
 		APPL_DEBUG("select same char");
 		char32_t comparechar = currentValue;
 		// Search back
-		for (Iterator it = --Iterator(_startPos);
-		     it == m_data.begin();
+		for (Iterator it = --position(_startPos);
+		     (bool)it == true;
 		     --it) {
 			currentValue = *it;
 			if (comparechar != currentValue) {
@@ -426,8 +506,8 @@ bool appl::Buffer::getPosAround(const appl::Buffer::Iterator& _startPos,
 			}
 		}
 		// Search forward
-		for (Iterator it = --Iterator(_startPos);
-		     it != m_data.end();
+		for (Iterator it = position(_startPos);
+		     (bool)it == true;
 		     ++it) {
 			currentValue = *it;
 			if (comparechar != currentValue) {
@@ -437,13 +517,13 @@ bool appl::Buffer::getPosAround(const appl::Buffer::Iterator& _startPos,
 		}
 		return true;
 	}
-	_beginPos = m_data.begin();
-	_endPos = m_data.begin();
+	_beginPos = begin();
+	_endPos = begin();
 	return false;
 }
 
 void appl::Buffer::setSelectionPos(const appl::Buffer::Iterator& _pos) {
-	m_cursorSelectPos = std::distance(m_data.begin(), _pos);
+	m_cursorSelectPos = _pos;
 	signalSelectChange.emit();
 }
 
@@ -499,8 +579,8 @@ appl::Buffer::Iterator appl::Buffer::countForwardNLines(const appl::Buffer::Iter
 	char32_t value;
 	int32_t lineCount = 0;
 	//APPL_INFO("startPos=" << startPos << " nLines=" << nLines);
-	for (Iterator it = Iterator(_startPos);
-	     it != m_data.end();
+	for (Iterator it = position(_startPos);
+	     (bool)it == true;
 	     ++it) {
 		value = *it;
 		if (value == u32char::Return) {
@@ -519,8 +599,8 @@ appl::Buffer::Iterator appl::Buffer::countBackwardNLines(const appl::Buffer::Ite
 	//APPL_INFO("startPos=" << startPos << " nLines=" << nLines);
 	char32_t value;
 	int32_t lineCount = 0;
-	for (Iterator it = --Iterator(_startPos);
-	     it != m_data.begin();
+	for (Iterator it = --position(_startPos);
+	     (bool)it == true;
 	     --it) {
 		value = *it;
 		if (value == u32char::Return) {
@@ -544,7 +624,7 @@ bool appl::Buffer::copy(std::string& _data) {
 		int32_t endPos = getStopSelectionPos();
 		for (Iterator it = position(startPos);
 		     it != position(endPos) &&
-		     it != m_data.end();
+		     (bool)it == true;
 		     ++it) {
 			_data += *it;
 		}
@@ -557,33 +637,39 @@ void appl::Buffer::copy(std::string& _data, const appl::Buffer::Iterator& _pos,
 	_data.clear();
 	for (Iterator it = _pos;
 	     it != _posEnd &&
-	     it != m_data.end();
+	     (bool)it == true;
 	     ++it) {
 		_data += *it;
 	}
 }
 
 bool appl::Buffer::write(const std::string& _data, const appl::Buffer::Iterator& _pos) {
-	std::u32string data2 = utf8::convertUnicode(_data);
-	APPL_VERBOSE("write at pos: " << std::distance(m_data.begin(), _pos) << " data : " << data2);
-	m_data.insert(_pos, data2.begin(), data2.end());
+	int64_t position = (int64_t)_pos;
+	if (position < 0){
+		position = 0;
+	}
+	APPL_VERBOSE("write at pos: " << (int64_t)_pos << " ==> " << position << " data : " << _data);
+	m_data.insert((size_t)position, _data);
 	if (m_cursorPos < 0) {
 		m_cursorPos = 0;
 	}
-	regenerateHighLightAt(std::distance(m_data.begin(), _pos), 0, data2.size());
+	regenerateHighLightAt(position, 0, _data.size());
 	m_selectMode = false;
-	moveCursor(std::distance(m_data.begin(),_pos+data2.size()));
+	moveCursor(position+_data.size());
 	countNumberofLine(); // TODO : use more intelligent counter
 	setModification(true);
 	return true;
 }
 
 bool appl::Buffer::replace(const std::string& _data, const appl::Buffer::Iterator& _pos, const appl::Buffer::Iterator& _posEnd) {
-	std::u32string data2 = utf8::convertUnicode(_data);
-	m_data.replace(_pos, _posEnd, data2.c_str(), data2.size());
-	regenerateHighLightAt(std::distance(m_data.begin(),_pos), std::distance(m_data.begin(),_posEnd)-std::distance(m_data.begin(),_pos), data2.size());
+	int64_t position = (int64_t)_pos;
+	if (position < 0){
+		position = 0;
+	}
+	m_data.replace(m_data.begin() + position, m_data.begin() + (int64_t)_posEnd, _data.begin(), _data.end());
+	regenerateHighLightAt(position, (int64_t)_posEnd-(int64_t)_pos, _data.size());
 	m_selectMode = false;
-	moveCursor(std::distance(m_data.begin(),_pos+data2.size()));
+	moveCursor(position+_data.size());
 	countNumberofLine(); // TODO : use more intelligent counter
 	setModification(true);
 	return true;
@@ -817,13 +903,13 @@ void appl::Buffer::hightlightGenerateLines(appl::DisplayHLData& _MData, const ap
 	//int64_t timeStart = ewol::getTime();
 	
 	appl::Buffer::Iterator HLStartLine = getStartLine(_HLStart);
-	int64_t HLStartPos = std::distance(m_data.begin(),HLStartLine);
+	int64_t HLStartPos = (int64_t)HLStartLine;
 	_MData.HLData.clear();
-	int64_t HLStop = std::distance(m_data.begin(),countForwardNLines(HLStartLine, _nbLines));
+	int64_t HLStop = (int64_t)countForwardNLines(HLStartLine, _nbLines);
 	int64_t startId = 0;
 	int64_t stopId = 0;
 	// find element previous
-	findMainHighLightPosition(std::distance(m_data.begin(),_HLStart), HLStop, startId, stopId, true);
+	findMainHighLightPosition(_HLStart, HLStop, startId, stopId, true);
 
 	//APPL_DEBUG("List of section between : "<< startId << " & " << stopId);
 	int64_t endSearch = stopId+1;
@@ -904,7 +990,7 @@ uint32_t appl::Buffer::getCursorLinesId() {
 	}
 	uint32_t line = 0;
 	for (Iterator it = begin();
-	     it != m_data.end() && it <= cursor();
+	    (bool)it == true && it <= cursor();
 	     ++it) {
 		if (*it == u32char::Return) {
 			++line;
diff --git a/sources/appl/Buffer.h b/sources/appl/Buffer.h
index 372b08c..d182f1a 100644
--- a/sources/appl/Buffer.h
+++ b/sources/appl/Buffer.h
@@ -29,7 +29,265 @@ namespace appl {
 	};
 	class Buffer : public ewol::Object {
 		public:
-			using Iterator = std::u32string::iterator;
+			class Iterator {
+				// Private data :
+				private:
+					int64_t m_current; //!< curent Id in the Buffer
+					appl::Buffer* m_data; //!< Pointer on the curent Buffer
+					char32_t m_value; //!< store vlue to prevent multiple calcule of getting the data
+				public:
+					/**
+					 * @brief Basic itarator constructor with no link.
+					 */
+					Iterator():
+					  m_current(0),
+					  m_data(nullptr),
+					  m_value(u32char::Null) {
+						// nothing to do ...
+					};
+					/**
+					 * @brief Recopy constructor.
+					 * @param[in] _obj The Iterator that might be copy
+					 */
+					Iterator(const Iterator & _obj):
+					  m_current(_obj.m_current),
+					  m_data(_obj.m_data),
+					  m_value(u32char::Null) {
+						// nothing to do ...
+					};
+					/**
+					 * @brief Asignation operator.
+					 * @param[in] _otherIterator The Iterator that might be copy
+					 * @return reference on the curent Iterator
+					 */
+					Iterator& operator=(const Iterator & _obj) {
+						m_current = _obj.m_current;
+						m_data = _obj.m_data;
+						m_value = u32char::Null;
+						return *this;
+					};
+					/**
+					 * @brief Basic destructor
+					 */
+					virtual ~Iterator() {
+						m_current = 0;
+						m_data = nullptr;
+						m_value = u32char::Null;
+					};
+					/**
+					 * @brief basic boolean cast
+					 * @return true if the element is present in buffer
+					 */
+					operator bool () const {
+						if (m_data == nullptr) {
+							return false;
+						}
+						if (m_current >= (int64_t)m_data->m_data.size()) {
+							return false;
+						}
+						if (m_current < 0) {
+							return false;
+						}
+						return true;
+					};
+					/**
+					 * @brief basic boolean cast
+					 * @return true if the element is present in buffer
+					 */
+					operator int64_t () const {
+						if (m_data == nullptr) {
+							return 0;
+						}
+						if (m_current < 0) {
+							return 0;
+						}
+						if (m_current > (int64_t)m_data->m_data.size()) {
+							return (int64_t)m_data->m_data.size();
+						}
+						return m_current;
+					};
+					/**
+					 * @brief Incremental operator
+					 * @return Reference on the current iterator incremented
+					 */
+					Iterator& operator++ ();
+					/**
+					 * @brief Decremental operator
+					 * @return Reference on the current iterator decremented
+					 */
+					Iterator& operator-- ();
+					/**
+					 * @brief Incremental operator
+					 * @return Reference on a new iterator and increment the other one
+					 */
+					Iterator operator++ (int32_t) {
+						Iterator it(*this);
+						++(*this);
+						return it;
+					};
+					/**
+					 * @brief Decremental operator
+					 * @return Reference on a new iterator and decrement the other one
+					 */
+					Iterator operator-- (int32_t) {
+						Iterator it(*this);
+						--(*this);
+						return it;
+					};
+					/**
+					 * @brief egality iterator
+					 * @return true if the iterator is identical pos
+					 */
+					bool operator== (const Iterator& _obj) const {
+						if (    m_current == _obj.m_current
+						     && m_data == _obj.m_data) {
+							return true;
+						}
+						return false;
+					};
+					/**
+					 * @brief egality iterator
+					 * @return true if the iterator is identical pos
+					 */
+					bool operator!= (const Iterator& _obj) const {
+						if (    m_current != _obj.m_current
+						     || m_data != _obj.m_data) {
+							return true;
+						}
+						return false;
+					};
+					/**
+					 * @brief <= iterator
+					 * @return true if the iterator is identical pos
+					 */
+					bool operator<= (const Iterator& _obj) const {
+						if (m_data != _obj.m_data) {
+							return false;
+						}
+						if (m_current <= _obj.m_current) {
+							return true;
+						}
+						return false;
+					};
+					/**
+					 * @brief >= iterator
+					 * @return true if the iterator is identical pos
+					 */
+					bool operator>= (const Iterator& _obj) const {
+						if (m_data != _obj.m_data) {
+							return false;
+						}
+						if (m_current >= _obj.m_current) {
+							return true;
+						}
+						return false;
+					};
+					/**
+					 * @brief < iterator
+					 * @return true if the iterator is identical pos
+					 */
+					bool operator< (const Iterator& _obj) const {
+						if (m_data != _obj.m_data) {
+							return false;
+						}
+						if (m_current < _obj.m_current) {
+							return true;
+						}
+						return false;
+					};
+					/**
+					 * @brief > iterator
+					 * @return true if the iterator is identical pos
+					 */
+					bool operator> (const Iterator& _obj) const {
+						if (m_data != _obj.m_data) {
+							return false;
+						}
+						if (m_current > _obj.m_current) {
+							return true;
+						}
+						return false;
+					};
+					/**
+					 * @brief Get the value on the current element
+					 * @return The request element value
+					 */
+					char32_t operator* ();
+					/**
+					 * @brief Get the position in the buffer
+					 * @return The requested position.
+					 */
+					int64_t getPos() const {
+						if (m_data == nullptr) {
+							return 0;
+						}
+						if (m_current < 0) {
+							return 0;
+						}
+						if (m_current >= (int64_t)m_data->m_data.size()) {
+							return m_data->m_data.size()-1;
+						}
+						return m_current;
+					};
+					/**
+					 * @brief move the element position
+					 * @return a new iterator.
+					 */
+					Iterator operator+ (const int64_t _val) const {
+						Iterator tmpp(*this);
+						for (int64_t iii=0; iii<_val; ++iii) {
+							++tmpp;
+						}
+						return tmpp;
+					};
+					Iterator operator+ (const int32_t _val) const {
+						Iterator tmpp(*this);
+						for (int64_t iii=0; iii<_val; ++iii) {
+							++tmpp;
+						}
+						return tmpp;
+					};
+					Iterator operator+ (const size_t _val) const {
+						Iterator tmpp(*this);
+						for (int64_t iii=0; iii<(int64_t)_val; ++iii) {
+							++tmpp;
+						}
+						return tmpp;
+					};
+					/**
+					 * @brief move the element position
+					 * @return a new iterator.
+					 */
+					Iterator operator- (const int64_t _val) const {
+						Iterator tmpp(*this);
+						for (int64_t iii=0; iii<_val; ++iii) {
+							--tmpp;
+						}
+						return tmpp;
+					};
+					Iterator operator- (const int32_t _val) const {
+						Iterator tmpp(*this);
+						for (int64_t iii=0; iii<_val; ++iii) {
+							--tmpp;
+						}
+						return tmpp;
+					};
+					Iterator operator- (const size_t _val) const {
+						Iterator tmpp(*this);
+						for (int64_t iii=0; iii<(int64_t)_val; ++iii) {
+							--tmpp;
+						}
+						return tmpp;
+					};
+				private:
+					Iterator(Buffer* _obj, int64_t _pos) :
+					  m_current(_pos),
+					  m_data(_obj),
+					  m_value(u32char::Null) {
+						// nothing to do ...
+					};
+					friend class Buffer;
+			};
 		public:
 			ewol::object::Signal<void> signalIsModify;
 			ewol::object::Signal<void> signalIsSave;
@@ -90,9 +348,9 @@ namespace appl {
 			 */
 			void setModification(bool _status);
 		protected:
-			std::u32string m_data; //!< copy of the file buffer
+			std::string m_data; //!< copy of the file buffer
 		public:
-			std::u32string& getData() {
+			std::string& getData() {
 				return m_data;
 			};
 		protected:
diff --git a/sources/appl/Gui/TextViewer.cpp b/sources/appl/Gui/TextViewer.cpp
index 1b2e978..2f0f07d 100644
--- a/sources/appl/Gui/TextViewer.cpp
+++ b/sources/appl/Gui/TextViewer.cpp
@@ -222,7 +222,7 @@ void appl::TextViewer::onRegenerateDisplay() {
 	int64_t startLineId = 0;
 	if (m_size.y() < m_displayText.getPos().y()) {
 		for (startingIt = m_buffer->begin();
-		     startingIt != m_buffer->end();
+		     (bool)startingIt == true;
 		     ++startingIt) {
 			if (*startingIt == u32char::Return) {
 				++startLineId;
@@ -275,7 +275,7 @@ void appl::TextViewer::onRegenerateDisplay() {
 	bool DisplayCursorAndSelection = isSelectedLast();
 	appl::Buffer::Iterator it;
 	for (it = startingIt;
-	     it != m_buffer->end();
+	     (bool)it == true;
 	     ++it) {
 		if (it == m_buffer->cursor()) {
 			// need to display the cursor :
@@ -307,7 +307,7 @@ void appl::TextViewer::onRegenerateDisplay() {
 			}
 			continue;
 		}
-		HLColor = m_buffer->getElementColorAtPosition(displayLocalSyntax, std::distance(m_buffer->begin(),it));
+		HLColor = m_buffer->getElementColorAtPosition(displayLocalSyntax, (int64_t)it);
 		bool haveBackground = false;
 		if (    HLColor != nullptr
 		     && HLColor->patern != nullptr) {
@@ -639,7 +639,7 @@ appl::Buffer::Iterator appl::TextViewer::getMousePosition(const vec2& _relativeP
 	m_displayText.forceLineReturn();
 	positionCurentDisplay = m_displayText.getPos();
 	for (appl::Buffer::Iterator it = m_buffer->begin();
-	     it != m_buffer->end();
+	     (bool)it == true;
 	     ++it) {
 		currentValue = *it;
 		if (currentValue == u32char::Return) {
@@ -756,7 +756,7 @@ bool appl::TextViewer::moveCursor(const appl::Buffer::Iterator& _pos) {
 		updateScrolling();
 		return true;
 	}
-	m_buffer->moveCursor(std::distance(m_buffer->begin(),_pos));
+	m_buffer->moveCursor((int64_t)_pos);
 	updateScrolling();
 	return true;
 }
@@ -937,7 +937,7 @@ appl::Buffer::Iterator appl::TextViewer::getPosSize(const appl::Buffer::Iterator
 	m_displayText.clear();
 	m_displayText.forceLineReturn();
 	for (appl::Buffer::Iterator it = _startLinePos;
-	     it != m_buffer->end();
+	     (bool)it == true;
 	     ++it) {
 		currentValue = *it;
 		m_buffer->expand(countColomn, currentValue, stringToDisplay);
@@ -965,7 +965,7 @@ float appl::TextViewer::getScreenSize(const appl::Buffer::Iterator& _startLinePo
 	m_displayText.clear();
 	
 	for (appl::Buffer::Iterator it = _startLinePos;
-	     it != m_buffer->end() && it <= _stopPos;
+	     (bool)it == true && it <= _stopPos;
 	     ++it) {
 		currentValue = *it;
 		//APPL_DEBUG("parse : " << currentValue);
diff --git a/sources/appl/Highlight.cpp b/sources/appl/Highlight.cpp
index 9143495..7583774 100644
--- a/sources/appl/Highlight.cpp
+++ b/sources/appl/Highlight.cpp
@@ -168,7 +168,7 @@ void appl::Highlight::parse(int64_t _start,
                             int64_t _stop,
                             std::vector<appl::HighlightInfo> & _metaData,
                             int64_t _addingPos,
-                            std::u32string& _buffer) {
+                            std::string& _buffer) {
 	if (0 > _addingPos) {
 		_addingPos = 0;
 	}
@@ -178,6 +178,8 @@ void appl::Highlight::parse(int64_t _start,
 	appl::HighlightInfo resultat;
 	while (elementStart <= elementStop) {
 		HL_DEBUG("Parse element in the buffer pos=" << elementStart);
+		appl::HighlightInfo resultatLast;
+		int64_t findAnOtherId = -1;
 		//try to fond the HL in ALL of we have
 		for (int64_t jjj=0; jjj<(int64_t)m_listHighlightPass1.size(); jjj++){
 			enum resultFind ret = HLP_FIND_OK;
@@ -185,38 +187,53 @@ void appl::Highlight::parse(int64_t _start,
 			// Stop the search to the end (to get the end of the pattern)
 			ret = m_listHighlightPass1[jjj]->find(elementStart, _buffer.size(), resultat, _buffer);
 			if (HLP_FIND_ERROR != ret) {
-				HL_DEBUG("Find Pattern in the Buffer : (" << resultat.start << "," << resultat.stop << ")" );
-				// remove element in the current List where the current Element have a end inside the next...
-				int64_t kkk=_addingPos;
-				while(kkk < (int64_t)_metaData.size() ) {
-					if (_metaData[kkk].start <= resultat.stop) {
-						// remove element
-						HL_DEBUG("Erase element=" << kkk);
-						_metaData.erase(_metaData.begin()+kkk, _metaData.begin()+kkk+1);
-						// Increase the end of search
-						if (kkk < (int64_t)_metaData.size()) {
-							// just befor the end of the next element
-							elementStop = _metaData[kkk].start-1;
-						} else {
-							// end of the buffer
-							elementStop = _buffer.size();
-						}
-					} else {
-						// Not find  == > exit the cycle : 
-						break;
+				if (elementStart == resultat.start) {
+					APPL_DEBUG("Find Pattern in the Buffer : (" << resultat.start << "," << resultat.stop << ") startPos=" << elementStart );
+					findAnOtherId = jjj;
+					resultatLast = resultat;
+					break;
+				} else {
+					// stack last find to prevent a unneded seach:
+					if (    findAnOtherId == -1
+					     || resultat.start < resultatLast.start) {
+						findAnOtherId = jjj;
+						resultatLast = resultat;
 					}
 				}
-				// add curent element in the list ...
-				_metaData.insert(_metaData.begin()+_addingPos, resultat);
-				HL_DEBUG("INSERT at "<< _addingPos << " S=" << resultat.start << " E=" << resultat.stop );
-				// update the current research starting element: (set position at the end of the current element
-				elementStart = resultat.stop-1;
-				// increment the position of insertion:
-				_addingPos++;
-				// We find a pattern  == > Stop search for the current element
-				break;
 			}
 		}
+		if (findAnOtherId != -1) {
+			// remove element in the current List where the current Element have a end inside the next...
+			int64_t kkk=_addingPos;
+			while(kkk < (int64_t)_metaData.size() ) {
+				if (_metaData[kkk].start <= resultatLast.stop) {
+					// remove element
+					HL_DEBUG("Erase element=" << kkk);
+					_metaData.erase(_metaData.begin()+kkk, _metaData.begin()+kkk+1);
+					// Increase the end of search
+					if (kkk < (int64_t)_metaData.size()) {
+						// just befor the end of the next element
+						elementStop = _metaData[kkk].start-1;
+					} else {
+						// end of the buffer
+						elementStop = _buffer.size();
+					}
+				} else {
+					// Not find  == > exit the cycle : 
+					break;
+				}
+			}
+			// add curent element in the list ...
+			_metaData.insert(_metaData.begin()+_addingPos, resultatLast);
+			HL_DEBUG("INSERT at "<< _addingPos << " S=" << resultatLast.start << " E=" << resultatLast.stop );
+			// update the current research starting element: (set position at the end of the current element
+			elementStart = resultatLast.stop-1;
+			// increment the position of insertion:
+			_addingPos++;
+			// We find a pattern  == > Stop search for the current element
+		} else {
+			break;
+		}
 		// Go to the next element (and search again ...).
 		elementStart++;
 	}
@@ -230,7 +247,7 @@ void appl::Highlight::parse(int64_t _start,
 void appl::Highlight::parse2(int64_t _start,
                              int64_t _stop,
                              std::vector<appl::HighlightInfo> &_metaData,
-                             std::u32string&_buffer) {
+                             std::string&_buffer) {
 	HL2_DEBUG("Parse element 0 => " << m_listHighlightPass2.size() <<
 	          "  == > position search: (" << _start << "," << _stop << ")" );
 	int64_t elementStart = _start;
diff --git a/sources/appl/Highlight.h b/sources/appl/Highlight.h
index 2359cd5..8dbb1ea 100644
--- a/sources/appl/Highlight.h
+++ b/sources/appl/Highlight.h
@@ -55,11 +55,11 @@ namespace appl {
 			           int64_t _stop,
 			           std::vector<appl::HighlightInfo> &_metaData,
 			           int64_t _addingPos,
-			           std::u32string &_buffer);
+			           std::string &_buffer);
 			void parse2(int64_t _start,
 			            int64_t _stop,
 			            std::vector<appl::HighlightInfo> &_metaData,
-			            std::u32string &_buffer);
+			            std::string &_buffer);
 		private:
 			void parseRules(exml::Element* _child,
 			                std::vector<std::unique_ptr<HighlightPattern>> &_mListPatern,
diff --git a/sources/appl/HighlightPattern.cpp b/sources/appl/HighlightPattern.cpp
index 389ee52..441403d 100644
--- a/sources/appl/HighlightPattern.cpp
+++ b/sources/appl/HighlightPattern.cpp
@@ -16,6 +16,8 @@
 appl::HighlightPattern::HighlightPattern(const std::shared_ptr<appl::GlyphPainting>& _glyphPainting) :
   m_glyphPainting(_glyphPainting),
   m_paternName(""),
+  m_hasParsingError(true),
+  m_regexValue(""),
   m_regExp(),
   m_colorName(""),
   m_level(0) {
@@ -28,13 +30,13 @@ appl::HighlightPattern::~HighlightPattern() {
 
 void appl::HighlightPattern::setPatern(const std::string& _regExp, bool forceMaximize) {
 	m_regexValue = _regExp;
-	const std::u32string data = utf8::convertUnicode(_regExp);
-	const std::u32string data2 = U"kjhkjhk";
-	const std::string data3 = "kjhkjhk";
-	//std::basic_regex<char32_t, std::u32string> regexp(data2);
-	std::basic_regex<char32_t> regexp((const char32_t*)data2.c_str());
-	//m_regExp.assign((const std::u32string)data);
-	//m_regExp.assign(_regExp);
+	try {
+		m_regExp.assign(_regExp);
+		m_hasParsingError = false;
+	} catch (std::regex_error e) {
+		m_hasParsingError = true;
+		APPL_ERROR("can not parse regExp : '" << e.what() << "' for : " << _regExp);
+	}
 	//m_regExp.setMaximize(forceMaximize);
 }
 std::string appl::HighlightPattern::getPaternString() {
@@ -97,17 +99,20 @@ void appl::HighlightPattern::parseRules(exml::Element* _child, int32_t _level, b
 	}
 }
 
-typedef std::match_results<std::u32string::const_iterator> s32match;
 
 enum resultFind appl::HighlightPattern::find(int32_t _start,
-                                     int32_t _stop,
-                                     appl::HighlightInfo& _resultat,
-                                     const std::u32string& _buffer) {
+                                             int32_t _stop,
+                                             appl::HighlightInfo& _resultat,
+                                             const std::string& _buffer) {
 	//APPL_DEBUG(" try to find the element");
 	_resultat.start = -1;
 	_resultat.stop = -1;
 	_resultat.notEnded = false;
 	_resultat.patern = this;
+	if (m_hasParsingError == true) {
+		return HLP_FIND_ERROR;
+	}
+	
 	/*
 	// when we have only one element:
 	if (true == m_regExp.processOneElement(_buffer, _start, _stop)) {
@@ -119,11 +124,13 @@ enum resultFind appl::HighlightPattern::find(int32_t _start,
 	return HLP_FIND_ERROR;
 	*/
 	
-	s32match resultMatch;
-	std::regex_search(_buffer, resultMatch, m_regExp);
+	std::smatch resultMatch;
+	//APPL_DEBUG("find data at : start=" << _start << " stop=" << _stop << " regex='" << m_regexValue << "'");
+	std::regex_search(_buffer.begin() + _start, _buffer.begin() + _stop, resultMatch, m_regExp);
 	if (resultMatch.size() > 0) {
 		_resultat.start = std::distance(_buffer.begin(), resultMatch[0].first);;
 		_resultat.stop = std::distance(_buffer.begin(), resultMatch[0].second);
+		//APPL_DEBUG("find data at : start=" << _resultat.start << " stop=" << _resultat.stop << " data='" <<std::string(_buffer, _resultat.start, _resultat.stop-_resultat.start) << "'" );
 		/*
 		if (false){
 			TK_DEBUG("in line : '" << etk::to_string(_buffer) << "'");
diff --git a/sources/appl/HighlightPattern.h b/sources/appl/HighlightPattern.h
index ec08f4c..59db43e 100644
--- a/sources/appl/HighlightPattern.h
+++ b/sources/appl/HighlightPattern.h
@@ -44,8 +44,9 @@ namespace appl {
 				return m_paternName;
 			};
 		private:
+			bool m_hasParsingError;
 			std::string m_regexValue;
-			std::basic_regex<char32_t> m_regExp; //!< Start of Regular expression
+			std::regex m_regExp; //!< Start of Regular expression
 		public:
 			void setPatern(const std::string& _regExp, bool forceMaximize=false);
 			std::string getPaternString();
@@ -83,7 +84,7 @@ namespace appl {
 			enum resultFind find(int32_t _start,
 			                     int32_t _stop,
 			                     appl::HighlightInfo& _resultat,
-			                     const std::u32string& _buffer);
+			                     const std::string& _buffer);
 			
 			void parseRules(exml::Element* _child, int32_t _level, bool forceMaximize=false);
 	};