Ejemplo n.º 1
0
        /// <summary>Converts this value to a <c>decimal</c> under the Common
        /// Language Infrastructure (usually a.NET Framework decimal).
        /// Currently, converts this value to the precision and range of a.NET
        /// Framework decimal.</summary>
        /// <returns>A <c>decimal</c> under the Common Language Infrastructure
        /// (usually a.NET Framework decimal).</returns>
        public decimal ToDecimal()
        {
            ERational extendedNumber = this;

            if (extendedNumber.IsInfinity() || extendedNumber.IsNaN())
            {
                throw new OverflowException("This object's value is out of range");
            }
            try {
                EDecimal newDecimal = EDecimal.FromEInteger(extendedNumber.Numerator)
                                      .Divide(
                    EDecimal.FromEInteger(extendedNumber.Denominator),
                    EContext.CliDecimal.WithTraps(EContext.FlagOverflow));
                return((decimal)newDecimal);
            } catch (ETrapException ex) {
                throw new OverflowException("This object's value is out of range", ex);
            }
        }
        public static ERational FromString(
            byte[] chars,
            int offset,
            int length,
            bool throwException)
        {
            int tmpoffset = offset;

            if (chars == null)
            {
                if (!throwException)
                {
                    return(null);
                }
                else
                {
                    throw new ArgumentNullException(nameof(chars));
                }
            }
            if (tmpoffset < 0)
            {
                if (!throwException)
                {
                    return(null);
                }
                else
                {
                    throw new FormatException("offset(" + tmpoffset + ") is" +
                                              "\u0020less" + "\u0020than " + "0");
                }
            }
            if (tmpoffset > chars.Length)
            {
                if (!throwException)
                {
                    return(null);
                }
                else
                {
                    throw new FormatException("offset(" + tmpoffset + ") is" +
                                              "\u0020more" + "\u0020than " + chars.Length);
                }
            }
            if (length < 0)
            {
                if (!throwException)
                {
                    return(null);
                }
                else
                {
                    throw new FormatException("length(" + length + ") is less than " + "0");
                }
            }
            if (length > chars.Length)
            {
                if (!throwException)
                {
                    return(null);
                }
                else
                {
                    throw new FormatException("length(" + length + ") is more than " +
                                              chars.Length);
                }
            }
            if (chars.Length - tmpoffset < length)
            {
                if (!throwException)
                {
                    return(null);
                }
                else
                {
                    throw new FormatException("chars's length minus " +
                                              tmpoffset + "(" + (chars.Length - tmpoffset) + ") is less than " + length);
                }
            }
            if (length == 0)
            {
                if (!throwException)
                {
                    return(null);
                }
                else
                {
                    throw new FormatException();
                }
            }
            var negative = false;
            int endStr   = tmpoffset + length;

            if (chars[tmpoffset] == '+' || chars[tmpoffset] == '-')
            {
                negative = chars[tmpoffset] == '-';
                ++tmpoffset;
            }
            var      numerInt        = 0;
            EInteger numer           = null;
            var      haveDigits      = false;
            var      haveDenominator = false;
            var      ndenomInt       = 0;
            EInteger ndenom          = null;
            int      i = tmpoffset;

            if (i + 8 == endStr)
            {
                if ((chars[i] == 'I' || chars[i] == 'i') &&
                    (chars[i + 1] == 'N' || chars[i + 1] == 'n') &&
                    (chars[i + 2] == 'F' || chars[i + 2] == 'f') &&
                    (chars[i + 3] == 'I' || chars[i + 3] == 'i') && (chars[i + 4] ==
                                                                     'N' ||
                                                                     chars[i + 4] == 'n') && (chars[i + 5] == 'I' || chars[i + 5] ==
                                                                                              'i') &&
                    (chars[i + 6] == 'T' || chars[i + 6] == 't') && (chars[i + 7] ==
                                                                     'Y' || chars[i + 7] == 'y'))
                {
                    return(negative ? ERational.NegativeInfinity :
                           ERational.PositiveInfinity);
                }
            }
            if (i + 3 == endStr)
            {
                if ((chars[i] == 'I' || chars[i] == 'i') &&
                    (chars[i + 1] == 'N' || chars[i + 1] == 'n') && (chars[i + 2] ==
                                                                     'F' || chars[i + 2] == 'f'))
                {
                    return(negative ? ERational.NegativeInfinity :
                           ERational.PositiveInfinity);
                }
            }
            var numerStart = 0;

            if (i + 3 <= endStr)
            {
                // Quiet NaN
                if ((chars[i] == 'N' || chars[i] == 'n') && (chars[i + 1] == 'A' ||
                                                             chars[i +
                                                                   1] == 'a') && (chars[i + 2] == 'N' || chars[i + 2] == 'n'))
                {
                    if (i + 3 == endStr)
                    {
                        return((!negative) ? ERational.NaN : ERational.NaN.Negate());
                    }
                    i         += 3;
                    numerStart = i;
                    for (; i < endStr; ++i)
                    {
                        if (chars[i] >= '0' && chars[i] <= '9')
                        {
                            var thisdigit = (int)(chars[i] - '0');
                            if (numerInt <= MaxSafeInt)
                            {
                                numerInt *= 10;
                                numerInt += thisdigit;
                            }
                        }
                        else
                        {
                            if (!throwException)
                            {
                                return(null);
                            }
                            else
                            {
                                throw new FormatException();
                            }
                        }
                    }
                    if (numerInt > MaxSafeInt)
                    {
                        numer = EInteger.FromSubstring(chars, numerStart, endStr);
                        return(ERational.CreateNaN(numer, false, negative));
                    }
                    else
                    {
                        return(ERational.CreateNaN(
                                   EInteger.FromInt32(numerInt),
                                   false,
                                   negative));
                    }
                }
            }
            if (i + 4 <= endStr)
            {
                // Signaling NaN
                if ((chars[i] == 'S' || chars[i] == 's') && (chars[i + 1] == 'N' ||
                                                             chars[i +
                                                                   1] == 'n') && (chars[i + 2] == 'A' || chars[i + 2] == 'a') &&
                    (chars[i + 3] == 'N' || chars[i + 3] == 'n'))
                {
                    if (i + 4 == endStr)
                    {
                        return((!negative) ? ERational.SignalingNaN :
                               ERational.SignalingNaN.Negate());
                    }
                    i         += 4;
                    numerStart = i;
                    for (; i < endStr; ++i)
                    {
                        if (chars[i] >= '0' && chars[i] <= '9')
                        {
                            var thisdigit = (int)(chars[i] - '0');
                            haveDigits = haveDigits || thisdigit != 0;
                            if (numerInt <= MaxSafeInt)
                            {
                                numerInt *= 10;
                                numerInt += thisdigit;
                            }
                        }
                        else
                        {
                            if (!throwException)
                            {
                                return(null);
                            }
                            else
                            {
                                throw new FormatException();
                            }
                        }
                    }
                    int flags3 = (negative ? BigNumberFlags.FlagNegative : 0) |
                                 BigNumberFlags.FlagSignalingNaN;
                    if (numerInt > MaxSafeInt)
                    {
                        numer = EInteger.FromSubstring(chars, numerStart, endStr);
                        return(ERational.CreateNaN(numer, true, negative));
                    }
                    else
                    {
                        return(ERational.CreateNaN(
                                   EInteger.FromInt32(numerInt),
                                   true,
                                   negative));
                    }
                }
            }
            // Ordinary number
            numerStart = i;
            int numerEnd = i;

            for (; i < endStr; ++i)
            {
                if (chars[i] >= '0' && chars[i] <= '9')
                {
                    var thisdigit = (int)(chars[i] - '0');
                    numerEnd = i + 1;
                    if (numerInt <= MaxSafeInt)
                    {
                        numerInt *= 10;
                        numerInt += thisdigit;
                    }
                    haveDigits = true;
                }
                else if (chars[i] == '/')
                {
                    haveDenominator = true;
                    ++i;
                    break;
                }
                else
                {
                    if (!throwException)
                    {
                        return(null);
                    }
                    else
                    {
                        throw new FormatException();
                    }
                }
            }
            if (!haveDigits)
            {
                if (!throwException)
                {
                    return(null);
                }
                else
                {
                    throw new FormatException();
                }
            }
            if (numerInt > MaxSafeInt)
            {
                numer = EInteger.FromSubstring(chars, numerStart, numerEnd);
            }
            if (haveDenominator)
            {
                EInteger denom    = null;
                var      denomInt = 0;
                tmpoffset  = 1;
                haveDigits = false;
                if (i == endStr)
                {
                    if (!throwException)
                    {
                        return(null);
                    }
                    else
                    {
                        throw new FormatException();
                    }
                }
                numerStart = i;
                for (; i < endStr; ++i)
                {
                    if (chars[i] >= '0' && chars[i] <= '9')
                    {
                        haveDigits = true;
                        var thisdigit = (int)(chars[i] - '0');
                        numerEnd = i + 1;
                        if (denomInt <= MaxSafeInt)
                        {
                            denomInt *= 10;
                            denomInt += thisdigit;
                        }
                    }
                    else
                    {
                        if (!throwException)
                        {
                            return(null);
                        }
                        else
                        {
                            throw new FormatException();
                        }
                    }
                }
                if (!haveDigits)
                {
                    if (!throwException)
                    {
                        return(null);
                    }
                    else
                    {
                        throw new FormatException();
                    }
                }
                if (denomInt > MaxSafeInt)
                {
                    denom = EInteger.FromSubstring(chars, numerStart, numerEnd);
                }
                if (denom == null)
                {
                    ndenomInt = denomInt;
                }
                else
                {
                    ndenom = denom;
                }
            }
            else
            {
                ndenomInt = 1;
            }
            if (i != endStr)
            {
                if (!throwException)
                {
                    return(null);
                }
                else
                {
                    throw new FormatException();
                }
            }
            if (ndenom == null ? (ndenomInt == 0) : ndenom.IsZero)
            {
                if (!throwException)
                {
                    return(null);
                }
                else
                {
                    throw new FormatException();
                }
            }
            ERational erat = ERational.Create(
                numer == null ? (EInteger)numerInt : numer,
                ndenom == null ? (EInteger)ndenomInt : ndenom);

            return(negative ? erat.Negate() : erat);
        }