/// <summary>
/// Integer
/// Handles the 16,32bit signed and unsigned integers
/// 64bit are handled separately
/// </summary>
private static void Integer(ref StackBuffer buffer, StackBuffer format, TypeCode type, long value, bool signed)
{
var negSign = signed && value < 0;
var fmt = ParseFormatSpecifier(format, out var digits);
var fmtUpper = (char)(fmt & 0xFFDF); // ensure fmt is upper-cased for purposes of comparison
if (fmtUpper == 'G' && digits < 1 || fmtUpper == 'D')
{
EvalInt(ref buffer, (ulong)Math.Abs(value), digits, 10, negSign);
}
else if (fmtUpper == 'X')
{
if (type == TypeCode.Int16)
{
if (value < 0)
{
EvalInt(ref buffer, (uint)(value & 0x0000FFFF), digits, 16, false);
return;
}
}
if (type == TypeCode.Int32)
{
if (value < 0)
{
EvalInt(ref buffer, (uint)(value & 0xFFFFFFFF), digits, 16, false);
return;
}
}
EvalInt(ref buffer, (ulong)Math.Abs(value), digits, 16, negSign);
}
}
/// <summary>
/// EvalArg
/// Entry point for evaluating the generic arguments
/// </summary>
private static void EvalArg <T>(ref StackBuffer buffer, StackBuffer format, T arg)
where T : IConvertible
{
switch (arg?.GetTypeCode())
{
case TypeCode.Int16:
{
Integer(ref buffer, format, arg.GetTypeCode(), arg.ToInt16(NumberFormatInfo.CurrentInfo), true);
break;
}
case TypeCode.Int32:
{
Integer(ref buffer, format, arg.GetTypeCode(), arg.ToInt32(NumberFormatInfo.CurrentInfo), true);
break;
}
case TypeCode.Int64:
{
Long(ref buffer, format, arg.GetTypeCode(), arg.ToInt64(NumberFormatInfo.CurrentInfo), true);
break;
}
case TypeCode.UInt16:
{
Integer(ref buffer, format, arg.GetTypeCode(), arg.ToUInt16(NumberFormatInfo.CurrentInfo), false);
break;
}
case TypeCode.UInt32:
{
Integer(ref buffer, format, arg.GetTypeCode(), arg.ToUInt32(NumberFormatInfo.CurrentInfo), false);
break;
}
case TypeCode.UInt64:
{
ULong(ref buffer, format, arg.GetTypeCode(), arg.ToUInt64(NumberFormatInfo.CurrentInfo), false);
break;
}
case TypeCode.Single:
{
FloatingPoint(ref buffer, format, arg.ToSingle(NumberFormatInfo.CurrentInfo));
break;
}
case TypeCode.Double:
{
FloatingPoint(ref buffer, format, arg.ToDouble(NumberFormatInfo.CurrentInfo));
break;
}
case TypeCode.String:
{
buffer.Append(arg.ToString());
break;
}
}
}
/// <summary>
/// EvalULong
/// Converts 64bit signed and unsigned ints to ascii
/// </summary>
private static void EvalULong(ref StackBuffer buffer, ulong longVal, int digits, long baseVal, bool negSign)
{
// add the characters in reverse order
do
{
// Lookup from static char array, to cover hex values too
buffer.Append(asciiDigits[longVal % (ulong)baseVal]);
longVal /= (ulong)baseVal;
digits--;
} while (longVal != 0);
Pad(ref buffer, digits, negSign);
}
// Set the string using the contents of a StackBuffer
public void SetStackBuffer(int destPos, StackBuffer buffer)
{
var newLength = destPos + buffer.Count;
if (destPos + buffer.Count > Capacity)
{
throw new ArgumentOutOfRangeException();
}
SetLength(newLength);
for (var i = destPos; i < newLength; i++)
{
this[i] = buffer[i];
}
}
private static void Pad(ref StackBuffer buffer, int digits, bool negSign)
{
// add preceding zeros
while (digits-- > 0)
{
buffer.Append('0');
}
// add sign
if (negSign)
{
buffer.Append('-');
}
// reverse it into the correct order
buffer.Reverse();
}
/// <summary>
/// Unsigned 64bit ints
/// </summary>
private static void ULong(ref StackBuffer buffer, StackBuffer format, TypeCode type, ulong value, bool signed)
{
var negSign = signed && value < 0;
var fmt = ParseFormatSpecifier(format, out var digits);
var fmtUpper = (char)(fmt & 0xFFDF); // ensure fmt is upper-cased for purposes of comparison
if (fmtUpper == 'G' && digits < 1 || fmtUpper == 'D')
{
EvalULong(ref buffer, value, digits, 10, negSign);
}
else if (fmtUpper == 'X')
{
EvalULong(ref buffer, value, digits, 16, negSign);
}
}
/// <summary>
/// EvalInt
/// Converts 16,32bit signed and unsigned ints to ascii
/// </summary>
private static void EvalInt(ref StackBuffer buffer, ulong intVal, int digits, ulong baseVal, bool negSign)
{
// add the characters in reverse order
do
{
// Lookup from static char array, to cover hex values too
buffer.Append(asciiDigits[intVal % baseVal]);
intVal /= baseVal;
digits--;
} while (intVal != 0);
// add preceding zeros
while (digits-- > 0)
{
buffer.Append('0');
}
// add sign
if (negSign)
{
buffer.Append('-');
}
// reverse it into the correct order
buffer.Reverse();
}
public static void Convert(ref StackBuffer buffer, double f, int precision)
{
if (f > ulong.MaxValue)
{
buffer.Append("Out-of-range");
return;
}
ulong intPart;
ulong baseVal = 10; // baseVal has to be the same type as the integer part
// check precision bounds
if (precision > MAX_PRECISION)
{
precision = MAX_PRECISION;
}
// sign stuff
if (f < 0)
{
f = -f;
buffer.Append('-');
}
if (precision < 0) // negative precision == automatic precision guess
{
if (f < 1.0)
{
precision = 6;
}
else if (f < 10.0)
{
precision = 5;
}
else if (f < 100.0)
{
precision = 4;
}
else if (f < 1000.0)
{
precision = 3;
}
else if (f < 10000.0)
{
precision = 2;
}
else if (f < 100000.0)
{
precision = 1;
}
else
{
precision = 0;
}
}
// round value according the precision
if (precision > 0)
{
f += rounders[precision];
}
// integer part...
intPart = (ulong)Math.Truncate(f);
f -= intPart;
if (intPart == 0)
{
buffer.Append('0');
}
else
{
var tempBuffer = new StackBuffer(stackalloc char[MAX_PRECISION]);
// convert (reverse order)
while (intPart != 0)
{
tempBuffer.Append((char)('0' + intPart % baseVal));
intPart /= baseVal;
}
tempBuffer.Reverse();
for (var i = 0; i < tempBuffer.Count; i++)
{
buffer.Append(tempBuffer[i]);
}
}
// decimal part
if (precision != 0)
{
// place decimal point
buffer.Append('.');
// convert
while (precision-- != 0)
{
f *= 10.0;
var c = (char)f;
buffer.Append((char)('0' + c));
f -= c;
}
}
}
/// <summary>
/// ParseFormatSpecifier
/// https://github.com/dotnet/runtime/blob/master/src/libraries/System.Private.CoreLib/src/System/Number.Formatting.cs
/// </summary>
/// <returns></returns>
private static char ParseFormatSpecifier(StackBuffer format, out int digits)
{
char c = default;
if (format.Length > 0)
{
// If the format begins with a symbol, see if it's a standard format
// with or without a specified number of digits.
c = format[0];
if ((uint)(c - 'A') <= 'Z' - 'A' ||
(uint)(c - 'a') <= 'z' - 'a')
{
// Fast path for sole symbol, e.g. "D"
if (format.Length == 1)
{
digits = -1;
return(c);
}
if (format.Length == 2)
{
// Fast path for symbol and single digit, e.g. "X4"
var d = format[1] - '0';
if ((uint)d < 10)
{
digits = d;
return(c);
}
}
else if (format.Length == 3)
{
// Fast path for symbol and double digit, e.g. "F12"
int d1 = format[1] - '0', d2 = format[2] - '0';
if ((uint)d1 < 10 && (uint)d2 < 10)
{
digits = d1 * 10 + d2;
return(c);
}
}
// Fallback for symbol and any length digits. The digits value must be >= 0 && <= 99,
// but it can begin with any number of 0s, and thus we may need to check more than two
// digits. Further, for compat, we need to stop when we hit a null char.
var n = 0;
var i = 1;
while (i < format.Length && (uint)format[i] - '0' < 10 && n < 10)
{
n = n * 10 + format[i++] - '0';
}
// If we're at the end of the digits rather than having stopped because we hit something
// other than a digit or overflowed, return the standard format info.
if (i == format.Length || format[i] == '\0')
{
digits = n;
return(c);
}
}
}
// Default empty format to be "G"; custom format is signified with '\0'.
digits = -1;
return(format.Length == 0 || c == '\0'
? // For compat, treat '\0' as the end of the specifier, even if the specifier extends beyond it.
'G'
: '\0');
}
/// <summary>
/// FloatingPoint
/// Handles single and double precision floating point values
/// </summary>
private static void FloatingPoint(ref StackBuffer buffer, StackBuffer format, double value)
{
var fmt = ParseFormatSpecifier(format, out var digits);
ftoa.Convert(ref buffer, value, digits);
}