internal static EFloat FromString(
char[] chars,
int offset,
int length,
EContext ctx,
bool throwException)
{
if (chars == null)
{
if (!throwException)
{
return(null);
}
else
{
throw new ArgumentNullException(nameof(chars));
}
}
if (offset < 0)
{
if (!throwException)
{
return(null);
}
else
{
throw new FormatException("offset(" + offset + ") is not" +
"\u0020greater" + "\u0020or equal to 0");
}
}
if (offset > chars.Length)
{
if (!throwException)
{
return(null);
}
else
{
throw new FormatException("offset(" + offset + ") is not" +
"\u0020less" + "\u0020or" + "\u0020equal to " + chars.Length);
}
}
if (length < 0)
{
if (!throwException)
{
return(null);
}
else
{
throw new FormatException("length(" + length + ") is not" +
"\u0020greater or" + "\u0020equal to 0");
}
}
if (length > chars.Length)
{
if (!throwException)
{
return(null);
}
else
{
throw new FormatException("length(" + length + ") is not" +
"\u0020less" + "\u0020or" + "\u0020equal to " + chars.Length);
}
}
if (chars.Length - offset < length)
{
if (!throwException)
{
return(null);
}
else
{
throw new FormatException("str's length minus " + offset + "(" +
(chars.Length - offset) + ") is not greater or equal to " + length);
}
}
EContext b64 = EContext.Binary64;
if (ctx != null && ctx.HasMaxPrecision && ctx.HasExponentRange &&
!ctx.IsSimplified && ctx.EMax.CompareTo(b64.EMax) <= 0 &&
ctx.EMin.CompareTo(b64.EMin) >= 0 &&
ctx.Precision.CompareTo(b64.Precision) <= 0)
{
int tmpoffset = offset;
int endpos = offset + length;
if (length == 0)
{
if (!throwException)
{
return(null);
}
else
{
throw new FormatException();
}
}
if (chars[tmpoffset] == '-' || chars[tmpoffset] == '+')
{
++tmpoffset;
}
if (tmpoffset < endpos && ((chars[tmpoffset] >= '0' &&
chars[tmpoffset] <= '9') || chars[tmpoffset] == '.'))
{
EFloat ef = DoubleEFloatFromString(
chars,
offset,
length,
ctx,
throwException);
if (ef != null)
{
return(ef);
}
}
}
return(EDecimal.FromString(
chars,
offset,
length,
EContext.Unlimited.WithSimplified(ctx != null && ctx.IsSimplified))
.ToEFloat(ctx));
}
internal static EFloat DoubleEFloatFromString(
char[] chars,
int offset,
int length,
EContext ctx,
bool throwException)
{
int tmpoffset = offset;
if (chars == null)
{
if (!throwException)
{
return(null);
}
else
{
throw new ArgumentNullException(nameof(chars));
}
}
if (length == 0)
{
if (!throwException)
{
return(null);
}
else
{
throw new FormatException();
}
}
int endStr = tmpoffset + length;
var negative = false;
var haveDecimalPoint = false;
var haveDigits = false;
var haveExponent = false;
var newScaleInt = 0;
var digitStart = 0;
int i = tmpoffset;
long mantissaLong = 0L;
// Ordinary number
if (chars[i] == '+' || chars[i] == '-')
{
if (chars[i] == '-')
{
negative = true;
}
++i;
}
digitStart = i;
int digitEnd = i;
int decimalDigitStart = i;
var haveNonzeroDigit = false;
var decimalPrec = 0;
int decimalDigitEnd = i;
var nonzeroBeyondMax = false;
var lastdigit = -1;
// 768 is maximum precision of a decimal
// half-ULP in double format
var maxDecimalPrec = 768;
if (length > 21)
{
int eminInt = ctx.EMin.ToInt32Checked();
int emaxInt = ctx.EMax.ToInt32Checked();
int precInt = ctx.Precision.ToInt32Checked();
if (eminInt >= -14 && emaxInt <= 15)
{
maxDecimalPrec = (precInt <= 11) ? 21 : 63;
}
else if (eminInt >= -126 && emaxInt <= 127)
{
maxDecimalPrec = (precInt <= 24) ? 113 : 142;
}
}
for (; i < endStr; ++i)
{
char ch = chars[i];
if (ch >= '0' && ch <= '9')
{
var thisdigit = (int)(ch - '0');
haveDigits = true;
haveNonzeroDigit |= thisdigit != 0;
if (decimalPrec > maxDecimalPrec)
{
if (thisdigit != 0)
{
nonzeroBeyondMax = true;
}
if (!haveDecimalPoint)
{
// NOTE: Absolute value will not be more than
// the char[] portion's length, so will fit comfortably
// in an 'int'.
newScaleInt = checked (newScaleInt + 1);
}
continue;
}
lastdigit = thisdigit;
if (haveNonzeroDigit)
{
++decimalPrec;
}
if (haveDecimalPoint)
{
decimalDigitEnd = i + 1;
}
else
{
digitEnd = i + 1;
}
if (mantissaLong <= 922337203685477580L)
{
mantissaLong *= 10;
mantissaLong += thisdigit;
}
else
{
mantissaLong = Int64.MaxValue;
}
if (haveDecimalPoint)
{
// NOTE: Absolute value will not be more than
// the portion's length, so will fit comfortably
// in an 'int'.
newScaleInt = checked (newScaleInt - 1);
}
}
else if (ch == '.')
{
if (haveDecimalPoint)
{
if (!throwException)
{
return(null);
}
else
{
throw new FormatException();
}
}
haveDecimalPoint = true;
decimalDigitStart = i + 1;
decimalDigitEnd = i + 1;
}
else if (ch == 'E' || ch == 'e')
{
haveExponent = true;
++i;
break;
}
else
{
if (!throwException)
{
return(null);
}
else
{
throw new FormatException();
}
}
}
if (!haveDigits)
{
if (!throwException)
{
return(null);
}
else
{
throw new FormatException();
}
}
var expInt = 0;
var expoffset = 1;
var expDigitStart = -1;
var expPrec = 0;
bool zeroMantissa = !haveNonzeroDigit;
haveNonzeroDigit = false;
EFloat ef1, ef2;
if (haveExponent)
{
haveDigits = false;
if (i == endStr)
{
if (!throwException)
{
return(null);
}
else
{
throw new FormatException();
}
}
char ch = chars[i];
if (ch == '+' || ch == '-')
{
if (ch == '-')
{
expoffset = -1;
}
++i;
}
expDigitStart = i;
for (; i < endStr; ++i)
{
ch = chars[i];
if (ch >= '0' && ch <= '9')
{
haveDigits = true;
var thisdigit = (int)(ch - '0');
haveNonzeroDigit |= thisdigit != 0;
if (haveNonzeroDigit)
{
++expPrec;
}
if (expInt <= 214748364)
{
expInt *= 10;
expInt += thisdigit;
}
else
{
expInt = Int32.MaxValue;
}
}
else
{
if (!throwException)
{
return(null);
}
else
{
throw new FormatException();
}
}
}
if (!haveDigits)
{
if (!throwException)
{
return(null);
}
else
{
throw new FormatException();
}
}
expInt *= expoffset;
if (expPrec > 12)
{
// Exponent that can't be compensated by digit
// length without remaining beyond Int32 range
if (expoffset < 0)
{
return(EFloat.SignalUnderflow(ctx, negative, zeroMantissa));
}
else
{
return(EFloat.SignalOverflow(ctx, negative, zeroMantissa));
}
}
}
if (i != endStr)
{
if (!throwException)
{
return(null);
}
else
{
throw new FormatException();
}
}
if (expInt != Int32.MaxValue && expInt > -Int32.MaxValue &&
mantissaLong != Int64.MaxValue && (ctx == null ||
!ctx.HasFlagsOrTraps))
{
if (mantissaLong == 0)
{
EFloat ef = EFloat.Create(
EInteger.Zero,
EInteger.FromInt32(expInt));
if (negative)
{
ef = ef.Negate();
}
return(ef.RoundToPrecision(ctx));
}
var finalexp = (long)expInt + (long)newScaleInt;
long ml = mantissaLong;
if (finalexp >= -22 && finalexp <= 44)
{
var iexp = (int)finalexp;
while (ml <= 900719925474099L && iexp > 22)
{
ml *= 10;
--iexp;
}
int iabsexp = Math.Abs(iexp);
if (ml < 9007199254740992L && iabsexp == 0)
{
return(EFloat.FromInt64(negative ?
-mantissaLong : mantissaLong).RoundToPrecision(ctx));
}
else if (ml < 9007199254740992L && iabsexp <= 22)
{
EFloat efn =
EFloat.FromEInteger(NumberUtility.FindPowerOfTen(iabsexp));
if (negative)
{
ml = -ml;
}
EFloat efml = EFloat.FromInt64(ml);
if (iexp < 0)
{
return(efml.Divide(efn, ctx));
}
else
{
return(efml.Multiply(efn, ctx));
}
}
}
long adjexpUpperBound = finalexp + (decimalPrec - 1);
long adjexpLowerBound = finalexp;
if (adjexpUpperBound < -326)
{
return(EFloat.SignalUnderflow(ctx, negative, zeroMantissa));
}
else if (adjexpLowerBound > 309)
{
return(EFloat.SignalOverflow(ctx, negative, zeroMantissa));
}
if (negative)
{
mantissaLong = -mantissaLong;
}
long absfinalexp = Math.Abs(finalexp);
ef1 = EFloat.Create(mantissaLong, (int)0);
ef2 = EFloat.FromEInteger(NumberUtility.FindPowerOfTen(absfinalexp));
if (finalexp < 0)
{
EFloat efret = ef1.Divide(ef2, ctx);
/* Console.WriteLine("div " + ef1 + "/" + ef2 + " -> " + (efret));
*/return(efret);
}
else
{
return(ef1.Multiply(ef2, ctx));
}
}
EInteger mant = null;
EInteger exp = (!haveExponent) ? EInteger.Zero :
EInteger.FromSubstring(chars, expDigitStart, endStr);
if (expoffset < 0)
{
exp = exp.Negate();
}
exp = exp.Add(newScaleInt);
if (nonzeroBeyondMax)
{
exp = exp.Subtract(1);
++decimalPrec;
}
EInteger adjExpUpperBound = exp.Add(decimalPrec).Subtract(1);
EInteger adjExpLowerBound = exp;
// DebugUtility.Log("exp=" + adjExpLowerBound + "~" + (adjExpUpperBound));
if (adjExpUpperBound.CompareTo(-326) < 0)
{
return(EFloat.SignalUnderflow(ctx, negative, zeroMantissa));
}
else if (adjExpLowerBound.CompareTo(309) > 0)
{
return(EFloat.SignalOverflow(ctx, negative, zeroMantissa));
}
if (zeroMantissa)
{
EFloat ef = EFloat.Create(
EInteger.Zero,
exp);
if (negative)
{
ef = ef.Negate();
}
return(ef.RoundToPrecision(ctx));
}
else if (decimalDigitStart != decimalDigitEnd)
{
if (digitEnd - digitStart == 1 && chars[digitStart] == '0')
{
mant = EInteger.FromSubstring(
chars,
decimalDigitStart,
decimalDigitEnd);
}
else
{
char[] ctmpstr = Extras.CharsConcat(
chars,
digitStart,
digitEnd - digitStart,
chars,
decimalDigitStart,
decimalDigitEnd - decimalDigitStart);
mant = EInteger.FromString(ctmpstr);
}
}
else
{
mant = EInteger.FromSubstring(chars, digitStart, digitEnd);
}
if (nonzeroBeyondMax)
{
mant = mant.Multiply(10).Add(1);
}
if (negative)
{
mant = mant.Negate();
}
return(EDecimal.Create(mant, exp).ToEFloat(ctx));
}