Add basic C++ output streaming support

Sming/Core/DateTime.cpp

@@ -271,13 +271,6 @@ String DateTime::format(const char* sFormat)
 
 	String sReturn;
 
-	// Append a number to the return buffer, padding to a fixed number of digits
-	auto appendNumber = [&sReturn](unsigned number, unsigned digits, char padChar = '0') {
-		char buf[8];
-		ultoa_wp(number, buf, 10, digits, padChar);
-		sReturn.concat(buf, digits);
-	};
-
 	char c;
 	while((c = *sFormat++) != '\0') {
 		if(c != '%') {
@@ -298,10 +291,10 @@ String DateTime::format(const char* sFormat)
 			sReturn += Year;
 			break;
 		case 'y': // Year, last 2 digits as a decimal number [00..99]
-			appendNumber(Year % 100, 2);
+			sReturn.concat(Year % 100, DEC, 2);
 			break;
 		case 'C': // Year, first 2 digits as a decimal number [00..99]
-			appendNumber(Year / 100, 2);
+			sReturn.concat(Year / 100, DEC, 2);
 			break;
 		// Month (not implemented: Om)
 		case 'b': // Abbreviated month name, e.g. Oct (always English)
@@ -312,18 +305,18 @@ String DateTime::format(const char* sFormat)
 			sReturn += CStringArray(flashMonthNames)[Month];
 			break;
 		case 'm': // Month as a decimal number [01..12]
-			appendNumber(Month + 1, 2);
+			sReturn.concat(Month + 1, DEC, 2);
 			break;
 		// Week (not implemented: OU, OW, OV)
 		case 'U': // Week of the year as a decimal number (Sunday is the first day of the week) [00..53]
-			appendNumber(calcWeek(0), 2);
+			sReturn.concat(calcWeek(0), DEC, 2);
 			break;
 		case 'V': // ISO 8601 week number (01-53)
 			// !@todo Calculation of ISO 8601 week number is crude and frankly wrong but does anyone care?
-			appendNumber(calcWeek(1) + 1, 2);
+			sReturn.concat(calcWeek(1) + 1, DEC, 2);
 			break;
 		case 'W': // Week of the year as a decimal number (Monday is the first day of the week) [00..53]
-			appendNumber(calcWeek(1), 2);
+			sReturn.concat(calcWeek(1), DEC, 2);
 			break;
 		case 'x': // Locale preferred date format
 			sReturn += format(_F(LOCALE_DATE));
@@ -333,13 +326,13 @@ String DateTime::format(const char* sFormat)
 			break;
 		// Day of year/month (Not implemented: Od, Oe)
 		case 'j': // Day of the year as a decimal number [001..366]
-			appendNumber(DayofYear, 3);
+			sReturn.concat(DayofYear, DEC, 3);
 			break;
 		case 'd': // Day of the month as a decimal number [01..31]
-			appendNumber(Day, 2);
+			sReturn.concat(Day, DEC, 2);
 			break;
 		case 'e': // Day of the month as a decimal number [ 1,31]
-			appendNumber(Day, 2, ' ');
+			sReturn.concat(Day, DEC, 2, ' ');
 			break;
 		// Day of week (Not implemented: Ow, Ou)
 		case 'w': // Weekday as a decimal number with Sunday as 0 [0..6]
@@ -356,16 +349,16 @@ String DateTime::format(const char* sFormat)
 			break;
 		// Time (not implemented: OH, OI, OM, OS)
 		case 'H': // Hour as a decimal number, 24 hour clock [00..23]
-			appendNumber(Hour, 2);
+			sReturn.concat(Hour, DEC, 2);
 			break;
 		case 'I': // Hour as a decimal number, 12 hour clock [0..12]
-			appendNumber(Hour ? ((Hour > 12) ? Hour - 12 : Hour) : 12, 2);
+			sReturn.concat(Hour ? ((Hour > 12) ? Hour - 12 : Hour) : 12, DEC, 2);
 			break;
 		case 'M': // Minute as a decimal number [00..59]
-			appendNumber(Minute, 2);
+			sReturn.concat(Minute, DEC, 2);
 			break;
 		case 'S': // Second as a decimal number [00..61]
-			appendNumber(Second, 2);
+			sReturn.concat(Second, DEC, 2);
 			break;
 		// Other (not implemented: Ec, Ex, EX, z, Z)
 		case 'c': // Locale preferred date and time format, e.g. Tue Dec 11 08:48:32 2018

Sming/Wiring/Print.cpp

@@ -38,29 +38,6 @@ size_t Print::write(const uint8_t* buffer, size_t size)
 	return n;
 }
 
-size_t Print::print(long num, int base)
-{
-	if(base == 0) {
-		return write(num);
-	}
-
-	if(base == 10 && num < 0) {
-		return print('-') + printNumber(static_cast<unsigned long>(-num), base);
-	}
-
-	return printNumber(static_cast<unsigned long>(num), base);
-}
-
-// Overload (signed long long)
-size_t Print::print(const long long& num, int base)
-{
-	if(base == 10 && num < 0) {
-		return print('-') + printNumber(static_cast<unsigned long long>(-num), base);
-	}
-
-	return printNumber(static_cast<unsigned long long>(num), base);
-}
-
 size_t Print::printf(const char* fmt, ...)
 {
 	size_t buffSize = INITIAL_PRINTF_BUFFSIZE;
@@ -83,17 +60,31 @@ size_t Print::printf(const char* fmt, ...)
 	}
 }
 
-size_t Print::printNumber(unsigned long num, uint8_t base)
+size_t Print::printNumber(unsigned long num, uint8_t base, uint8_t width, char pad)
+{
+	char buf[8 * sizeof(num) + 1]; // Assumes 8-bit chars plus zero byte.
+	ultoa_wp(num, buf, base, width, pad);
+	return write(buf);
+}
+
+size_t Print::printNumber(const unsigned long long& num, uint8_t base, uint8_t width, char pad)
+{
+	char buf[8 * sizeof(num) + 1]; // Assumes 8-bit chars plus zero byte.
+	ulltoa_wp(num, buf, base, width, pad);
+	return write(buf);
+}
+
+size_t Print::printNumber(long num, uint8_t base, uint8_t width, char pad)
 {
 	char buf[8 * sizeof(num) + 1]; // Assumes 8-bit chars plus zero byte.
-	ultoa(num, buf, base);
+	ltoa_wp(num, buf, base, width, pad);
 	return write(buf);
 }
 
-size_t Print::printNumber(const unsigned long long& num, uint8_t base)
+size_t Print::printNumber(const long long& num, uint8_t base, uint8_t width, char pad)
 {
 	char buf[8 * sizeof(num) + 1]; // Assumes 8-bit chars plus zero byte.
-	ulltoa(num, buf, base);
+	lltoa_wp(num, buf, base, width, pad);
 	return write(buf);
 }
 

Sming/Wiring/Print.h

@@ -115,7 +115,7 @@ class Print
 	  *
 	  * @{
 	  */
-	size_t print(unsigned long num, int base = DEC)
+	size_t print(unsigned long num, uint8_t base = DEC)
 	{
 		if(base == 0) {
 			return write(num);
@@ -124,28 +124,48 @@ class Print
 		}
 	}
 
-	size_t print(const unsigned long long& num, int base = DEC)
+	template <typename... Args> size_t print(unsigned long num, Args... args)
 	{
-		return printNumber(num, base);
+		return printNumber(num, args...);
 	}
 
-	size_t print(long, int base = DEC);
+	template <typename... Args> size_t print(const unsigned long long& num, Args... args)
+	{
+		return printNumber(num, args...);
+	}
 
-	size_t print(const long long&, int base = DEC);
+	size_t print(long num, uint8_t base = DEC)
+	{
+		if(base == 0) {
+			return write(num);
+		} else {
+			return printNumber(num, base);
+		}
+	}
 
-	size_t print(unsigned int num, int base = DEC)
+	template <typename... Args> size_t print(long num, Args... args)
 	{
-		return print((unsigned long)num, base);
+		return printNumber(num, args...);
 	}
 
-	size_t print(unsigned char num, int base = DEC)
+	template <typename... Args> size_t print(const long long& num, Args... args)
 	{
-		return print((unsigned long)num, base);
+		return printNumber(num, args...);
 	}
 
-	size_t print(int num, int base = DEC)
+	template <typename... Args> size_t print(unsigned int num, Args... args)
 	{
-		return print((long)num, base);
+		return print((unsigned long)num, args...);
+	}
+
+	template <typename... Args> size_t print(unsigned char num, Args... args)
+	{
+		return print((unsigned long)num, args...);
+	}
+
+	template <typename... Args> size_t print(int num, Args... args)
+	{
+		return printNumber((long)num, args...);
 	}
 	/** @} */
 
@@ -177,101 +197,30 @@ class Print
 		return write(s.c_str(), s.length());
 	}
 
-	/** @brief  Prints a newline to output stream
-	  * @retval size_t Quantity of characters written to stream
-	  */
-	size_t println()
-	{
-		return print("\r\n");
-	}
-
-	/** @brief  Prints a c-string to output stream, appending newline
-	  * @param  str c-string to print
-	  * @retval size_t Quantity of characters written to stream
-	  */
-	size_t println(const char str[])
-	{
-		return print(str) + println();
-	}
-
-	/** @brief  Prints a single character to output stream, appending newline
-	  * @param  c Character to print
-	  * @retval size_t Quantity of characters written to stream
-	  */
-	size_t println(char c)
-	{
-		return print(c) + println();
-	}
-
-	/** @name   Print an integral number to output stream, appending newline
-	  * @param  num Number to print
-	  * @param  base The base for output (Default: Decimal (base 10))
-	  * @retval size_t Quantity of characters written to stream
-	  *
-	  * @{
-	  */
-	size_t println(unsigned char num, int base = DEC)
-	{
-		return print(num, base) + println();
-	}
-
-	size_t println(unsigned int num, int base = DEC)
-	{
-		return print(num, base) + println();
-	}
-
-	size_t println(unsigned long num, int base = DEC)
-	{
-		return print(num, base) + println();
-	}
-
-	size_t println(const unsigned long long& num, int base = DEC)
-	{
-		return print(num, base) + println();
-	}
-
-	size_t println(int num, int base = DEC)
-	{
-		return print(num, base) + println();
-	}
-
-	size_t println(long num, int base = DEC)
-	{
-		return print(num, base) + println();
-	}
-
-	size_t println(const long long& num, int base = DEC)
-	{
-		return print(num, base) + println();
-	}
-	/** @} */
-
-	/** @brief  Print a floating-point number to output stream, appending newline
-	  * @param  num Number to print
-	  * @param  digits The decimal places to print (Default: 2, e.g. 21.35)
-	  * @retval size_t Quantity of characters written to stream
-	  */
-	size_t println(double num, int digits = 2)
+	/**
+	 * @brief enums can be printed as strings provided they have a `toString(E)` implementation.
+	 */
+	template <typename E>
+	typename std::enable_if<std::is_enum<E>::value && !std::is_convertible<E, int>::value, size_t>::type print(E value)
 	{
-		return print(num, digits) + println();
+		extern String toString(E e);
+		return print(toString(value));
 	}
 
-	/** @brief  Prints a Printable object to output stream, appending newline
-	  * @param  p Object to print
+	/** @brief  Prints a newline to output stream
 	  * @retval size_t Quantity of characters written to stream
 	  */
-	size_t println(const Printable& p)
+	size_t println()
 	{
-		return print(p) + println();
+		return print("\r\n");
 	}
 
-	/** @brief  Prints a String to output stream, appending newline
-	  * @param  s String to print
+	/** @brief Print value plus newline to output stream
 	  * @retval size_t Quantity of characters written to stream
 	  */
-	size_t println(const String& s)
+	template <typename... Args> size_t println(const Args&... args)
 	{
-		return print(s) + println();
+		return print(args...) + println();
 	}
 
 	/** @brief  Prints a formatted c-string to output stream
@@ -284,8 +233,10 @@ class Print
 
 private:
 	int write_error = 0;
-	size_t printNumber(unsigned long num, uint8_t base);
-	size_t printNumber(const unsigned long long& num, uint8_t base);
+	size_t printNumber(unsigned long num, uint8_t base = DEC, uint8_t width = 0, char pad = '0');
+	size_t printNumber(const unsigned long long& num, uint8_t base = DEC, uint8_t width = 0, char pad = '0');
+	size_t printNumber(long num, uint8_t base = DEC, uint8_t width = 0, char pad = '0');
+	size_t printNumber(const long long& num, uint8_t base = DEC, uint8_t width = 0, char pad = '0');
 	size_t printFloat(double num, uint8_t digits);
 
 protected:
@@ -295,6 +246,23 @@ class Print
 	}
 };
 
+template <typename T> Print& operator<<(Print& p, const T& value)
+{
+	p.print(value);
+	return p;
+}
+
+// Thanks to Arduino forum user Paul V. who suggested this
+// clever technique to allow for expressions like
+//   Serial << "Hello!" << endl;
+enum EndLineCode { endl };
+
+inline Print& operator<<(Print& p, EndLineCode)
+{
+	p.println();
+	return p;
+}
+
 /** @} */
 
 #endif // __cplusplus