add methods: try_esc_to_json(wchar_t val, stream) try_esc_to_xml(...) try_esc_to_csv(...)

Those methods return true if the val character was escaped and put
to the out stream. If the character is invalid for such a stream
they only return true without putting it to the stream.

src/convert/misc.cpp

@@ -73,48 +73,70 @@ void esc_to_json_uformat(wchar_t val, Stream & out)
 }
 
 
-void esc_to_json(wchar_t val, Stream & out)
+/*
+ * return true if the val character was escaped and put to the out stream
+ * if the character is invalid for such a stream then only return true
+ * but not put it to the stream
+ */
+bool try_esc_to_json(wchar_t val, Stream & out)
 {
+	bool status = false;
+
 	if( val == '\r' )
 	{
 		out << '\\' << 'r';
+		status = true;
 	}
 	else
 	if( val == '\n' )
 	{
 		out << '\\' << 'n';
+		status = true;
 	}
 	else
 	if( val == '\t' )
 	{
 		out << '\\' << 't';
+		status = true;
 	}
 	else
 	if( val == 0x08 )
 	{
 		out << '\\' << 'b';
+		status = true;
 	}
 	else
 	if( val == 0x0c )
 	{
 		out << '\\' << 'f';
+		status = true;
 	}
 	else
 	if( val == '\\' )
 	{
 		out << '\\' << '\\';
+		status = true;
 	}
 	else
 	if( val == '"' )
 	{
 		out << '\\' << '\"';
+		status = true;
 	}
 	else
 	if( val < 32 )
 	{
 		esc_to_json_uformat(val, out);
+		status = true;
 	}
-	else
+
+	return status;
+}
+
+
+void esc_to_json(wchar_t val, Stream & out)
+{
+	if( !try_esc_to_json(val, out) )
 	{
 		out << val;
 	}
@@ -123,7 +145,10 @@ void esc_to_json(wchar_t val, Stream & out)
 
 void esc_to_json(char val, Stream & out)
 {
-	esc_to_json((wchar_t)(unsigned char)val, out);
+	if( !try_esc_to_json((wchar_t)(unsigned char)val, out) )
+	{
+		out << val;
+	}
 }
 
 
@@ -177,44 +202,66 @@ void esc_to_json(const std::wstring & in, Stream & out)
 
 
 
-
-
-
-void esc_to_xml(wchar_t val, Stream & out)
+/*
+ * return true if the val character was escaped and put to the out stream
+ * if the character is invalid for such a stream then only return true
+ * but not put it to the stream
+ */
+bool try_esc_to_xml(wchar_t val, Stream & out)
 {
-	switch(val)
+	bool status = false;
+
+	if( val == 0 )
 	{
-	case 0:
 		// null character is invalid in XML 1.0 and 1.1
 		// https://en.wikipedia.org/wiki/Valid_characters_in_XML
-		break;
-
-	case '<':
+		// return true but not put the char to the out stream
+		status = true;
+	}
+	else
+	if( val == '<')
+	{
 		out << "&lt;";
-		break;
-
-	case '>':
+		status = true;
+	}
+	else
+	if( val == '>')
+	{
 		out << "&gt;";
-		break;
-
-	case '&':
+		status = true;
+	}
+	else
+	if( val == '&')
+	{
 		out << "&amp;";
-		break;
-
-	case '"':
+		status = true;
+	}
+	else
+	if( val == '"')
+	{
 		out << "&quot;";
-		break;
+		status = true;
+	}
+
+	return status;
+}
+
 
-	default:
+void esc_to_xml(wchar_t val, Stream & out)
+{
+	if( !try_esc_to_xml(val, out) )
+	{
 		out << val;
-		break;
 	}
 }
 
 
 void esc_to_xml(char val, Stream & out)
 {
-	esc_to_xml((wchar_t)(unsigned char)val, out);
+	if( !try_esc_to_xml((wchar_t)(unsigned char)val, out) )
+	{
+		out << val;
+	}
 }
 
 
@@ -269,28 +316,47 @@ void esc_to_xml(const std::wstring & in, Stream & out)
 
 
 
-void esc_to_csv(wchar_t c, pt::Stream & out)
+/*
+ * return true if the val character was escaped and put to the out stream
+ * if the character is invalid for such a stream then only return true
+ * but not put it to the stream
+ */
+bool try_esc_to_csv(wchar_t val, pt::Stream & out)
 {
-	switch(c)
+	bool status = false;
+
+	if( val == 0 )
 	{
-	case 0:
 		// null characters are invalid in text files
-		break;
-
-	case '"':
+		// return true but not put to the out stream
+		status = true;
+	}
+	else
+	if( val == '"' )
+	{
 		out << "\"\"";
-		break;
+		status = true;
+	}
+
+	return status;
+}
+
 
-	default:
-		out << c;
-		break;
+void esc_to_csv(wchar_t val, pt::Stream & out)
+{
+	if( !try_esc_to_csv(val, out) )
+	{
+		out << val;
 	}
 }
 
 
 void esc_to_csv(char val, Stream & out)
 {
-	esc_to_csv((wchar_t)(unsigned char)val, out);
+	if( !try_esc_to_csv((wchar_t)(unsigned char)val, out) )
+	{
+		out << val;
+	}
 }
 
 

src/convert/misc.h

@@ -50,6 +50,7 @@ namespace pt
 
 void SetOverflow(bool * was_overflow, bool val);
 
+bool try_esc_to_json(wchar_t val, Stream & out);
 void esc_to_json(wchar_t val, Stream & out);
 void esc_to_json(char val, Stream & out);
 void esc_to_json(const char * c, pt::Stream & out);
@@ -59,6 +60,7 @@ void esc_to_json(const wchar_t * c, size_t len, pt::Stream & out);
 void esc_to_json(const std::string & in, Stream & out);
 void esc_to_json(const std::wstring & in, Stream & out);
 
+bool try_esc_to_xml(wchar_t val, Stream & out);
 void esc_to_xml(wchar_t c, pt::Stream & out);
 void esc_to_xml(char c, pt::Stream & out);
 void esc_to_xml(const char * c, pt::Stream & out);
@@ -68,6 +70,7 @@ void esc_to_xml(const wchar_t * c, size_t len, pt::Stream & out);
 void esc_to_xml(const std::string & in, Stream & out);
 void esc_to_xml(const std::wstring & in, Stream & out);
 
+bool try_esc_to_csv(wchar_t val, pt::Stream & out);
 void esc_to_csv(wchar_t val, Stream & out);
 void esc_to_csv(char c, pt::Stream & out);
 void esc_to_csv(const char * c, std::size_t len, Stream & out);