SQLDouble.cs source code in C# .NET

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/ DotNET / DotNET / 8.0 / untmp / whidbey / REDBITS / ndp / fx / src / Data / System / Data / SQLTypes / SQLDouble.cs / 1 / SQLDouble.cs

                            //------------------------------------------------------------------------------ 
// 
//     Copyright (c) Microsoft Corporation.  All rights reserved.
//  
// junfang 
// [....]
// [....] 
//----------------------------------------------------------------------------- 

//************************************************************************* 
// @File: SqlDouble.cs
//
// Create by:    JunFang
// 
// Purpose: Implementation of SqlDouble which is equivalent to
//            data type "float" in SQL Server 
// 
// Notes:
// 
// History:
//
//   09/17/99  JunFang    Created and implemented as first drop.
// 
// @EndHeader@
//************************************************************************* 
 
using System;
using System.Data.Common; 
using System.Runtime.InteropServices;
using System.Globalization;
using System.Xml;
using System.Xml.Schema; 
using System.Xml.Serialization;
 
namespace System.Data.SqlTypes { 

    ///  
    ///    
    ///       Represents a floating-point number within the range of
    ///       -1.79E
    ///       +308 through 1.79E +308 to be stored in or retrieved from 
    ///       a database.
    ///     
    ///  
    [Serializable]
    [StructLayout(LayoutKind.Sequential)] 
    [XmlSchemaProvider("GetXsdType")]
    public struct SqlDouble : INullable, IComparable, IXmlSerializable {

        private bool m_fNotNull; // false if null 
        private double m_value;
 
        // constructor 
        // construct a Null
        private SqlDouble(bool fNull) { 
            m_fNotNull = false;
            m_value = 0.0;
        }
 
        /// 
        ///    [To be supplied.] 
        ///  
        public SqlDouble(double value) {
            if (Double.IsInfinity(value) || Double.IsNaN(value)) 
                throw new OverflowException(SQLResource.ArithOverflowMessage);
            else {
                m_value = value;
                m_fNotNull = true; 
            }
        } 
 
        // INullable
        ///  
        ///    [To be supplied.]
        /// 
        public bool IsNull {
            get { return !m_fNotNull;} 
        }
 
        // property: Value 
        /// 
        ///    [To be supplied.] 
        /// 
        public double Value {
            get {
                if (m_fNotNull) 
                    return m_value;
                else 
                    throw new SqlNullValueException(); 
            }
        } 

        // Implicit conversion from double to SqlDouble
        /// 
        ///    [To be supplied.] 
        /// 
        public static implicit operator SqlDouble(double x) { 
            return new SqlDouble(x); 
        }
 
        // Explicit conversion from SqlDouble to double. Throw exception if x is Null.
        /// 
        ///    [To be supplied.]
        ///  
        public static explicit operator double(SqlDouble x) {
            return x.Value; 
        } 

        ///  
        ///    [To be supplied.]
        /// 
        public override String ToString() {
            return IsNull ? SQLResource.NullString : m_value.ToString((IFormatProvider)null); 
        }
 
        ///  
        ///    [To be supplied.]
        ///  
        public static SqlDouble Parse(String s) {
            if (s == SQLResource.NullString)
                return SqlDouble.Null;
            else 
                return new SqlDouble(Double.Parse(s, CultureInfo.InvariantCulture));
        } 
 

        // Unary operators 
        /// 
        ///    [To be supplied.]
        /// 
        public static SqlDouble operator -(SqlDouble x) { 
            return x.IsNull ? Null : new SqlDouble(-x.m_value);
        } 
 

        // Binary operators 

        // Arithmetic operators
        /// 
        ///    [To be supplied.] 
        /// 
        public static SqlDouble operator +(SqlDouble x, SqlDouble y) { 
            if (x.IsNull || y.IsNull) 
                return Null;
 
            double value = x.m_value + y.m_value;

            if (Double.IsInfinity(value))
                throw new OverflowException(SQLResource.ArithOverflowMessage); 

            return new SqlDouble(value); 
        } 

        ///  
        ///    [To be supplied.]
        /// 
        public static SqlDouble operator -(SqlDouble x, SqlDouble y) {
            if (x.IsNull || y.IsNull) 
                return Null;
 
            double value = x.m_value - y.m_value; 

            if (Double.IsInfinity(value)) 
                throw new OverflowException(SQLResource.ArithOverflowMessage);

            return new SqlDouble(value);
        } 

        ///  
        ///    [To be supplied.] 
        /// 
        public static SqlDouble operator *(SqlDouble x, SqlDouble y) { 
            if (x.IsNull || y.IsNull)
                return Null;

            double value = x.m_value * y.m_value; 

            if (Double.IsInfinity(value)) 
                throw new OverflowException(SQLResource.ArithOverflowMessage); 

            return new SqlDouble(value); 
        }

        /// 
        ///    [To be supplied.] 
        /// 
        public static SqlDouble operator /(SqlDouble x, SqlDouble y) { 
            if (x.IsNull || y.IsNull) 
                return Null;
 
            if (y.m_value == (double)0.0)
                throw new DivideByZeroException(SQLResource.DivideByZeroMessage);

            double value = x.m_value / y.m_value; 

            if (Double.IsInfinity(value)) 
                throw new OverflowException(SQLResource.ArithOverflowMessage); 

            return new SqlDouble(value); 
        }


 
        // Implicit conversions
 
        // Implicit conversion from SqlBoolean to SqlDouble 
        /// 
        ///    [To be supplied.] 
        /// 
        public static explicit operator SqlDouble(SqlBoolean x) {
            return x.IsNull ? Null : new SqlDouble((double)(x.ByteValue));
        } 

        // Implicit conversion from SqlByte to SqlDouble 
        ///  
        ///    [To be supplied.]
        ///  
        public static implicit operator SqlDouble(SqlByte x) {
            return x.IsNull ? Null : new SqlDouble((double)(x.Value));
        }
 
        // Implicit conversion from SqlInt16 to SqlDouble
        ///  
        ///    [To be supplied.] 
        /// 
        public static implicit operator SqlDouble(SqlInt16 x) { 
            return x.IsNull ? Null : new SqlDouble((double)(x.Value));
        }

        // Implicit conversion from SqlInt32 to SqlDouble 
        /// 
        ///    [To be supplied.] 
        ///  
        public static implicit operator SqlDouble(SqlInt32 x) {
            return x.IsNull ? Null : new SqlDouble((double)(x.Value)); 
        }

        // Implicit conversion from SqlInt64 to SqlDouble
        ///  
        ///    [To be supplied.]
        ///  
        public static implicit operator SqlDouble(SqlInt64 x) { 
            return x.IsNull ? Null : new SqlDouble((double)(x.Value));
        } 

        // Implicit conversion from SqlSingle to SqlDouble
        /// 
        ///    [To be supplied.] 
        /// 
        public static implicit operator SqlDouble(SqlSingle x) { 
            return x.IsNull ? Null : new SqlDouble((double)(x.Value)); 
        }
 
        // Implicit conversion from SqlMoney to SqlDouble
        /// 
        ///    [To be supplied.]
        ///  
        public static implicit operator SqlDouble(SqlMoney x) {
            return x.IsNull ? Null : new SqlDouble(x.ToDouble()); 
        } 

        // Implicit conversion from SqlDecimal to SqlDouble 
        /// 
        ///    [To be supplied.]
        /// 
        public static implicit operator SqlDouble(SqlDecimal x) { 
            return x.IsNull ? Null : new SqlDouble(x.ToDouble());
        } 
 

        // Explicit conversions 



        // Explicit conversion from SqlString to SqlDouble 
        // Throws FormatException or OverflowException if necessary.
        ///  
        ///    [To be supplied.] 
        /// 
        public static explicit operator SqlDouble(SqlString x) { 
            if (x.IsNull)
                return SqlDouble.Null;

            return Parse(x.Value); 
        }
 
        // Overloading comparison operators 
        /// 
        ///    [To be supplied.] 
        /// 
        public static SqlBoolean operator==(SqlDouble x, SqlDouble y) {
            return(x.IsNull || y.IsNull) ? SqlBoolean.Null : new SqlBoolean(x.m_value == y.m_value);
        } 

        ///  
        ///    [To be supplied.] 
        /// 
        public static SqlBoolean operator!=(SqlDouble x, SqlDouble y) { 
            return ! (x == y);
        }

        ///  
        ///    [To be supplied.]
        ///  
        public static SqlBoolean operator<(SqlDouble x, SqlDouble y) { 
            return(x.IsNull || y.IsNull) ? SqlBoolean.Null : new SqlBoolean(x.m_value < y.m_value);
        } 

        /// 
        ///    [To be supplied.]
        ///  
        public static SqlBoolean operator>(SqlDouble x, SqlDouble y) {
            return(x.IsNull || y.IsNull) ? SqlBoolean.Null : new SqlBoolean(x.m_value > y.m_value); 
        } 

        ///  
        ///    [To be supplied.]
        /// 
        public static SqlBoolean operator<=(SqlDouble x, SqlDouble y) {
            return(x.IsNull || y.IsNull) ? SqlBoolean.Null : new SqlBoolean(x.m_value <= y.m_value); 
        }
 
        ///  
        ///    [To be supplied.]
        ///  
        public static SqlBoolean operator>=(SqlDouble x, SqlDouble y) {
            return(x.IsNull || y.IsNull) ? SqlBoolean.Null : new SqlBoolean(x.m_value >= y.m_value);
        }
 
        //--------------------------------------------------
        // Alternative methods for overloaded operators 
        //-------------------------------------------------- 

        // Alternative method for operator + 
        public static SqlDouble Add(SqlDouble x, SqlDouble y) {
            return x + y;
        }
        // Alternative method for operator - 
        public static SqlDouble Subtract(SqlDouble x, SqlDouble y) {
            return x - y; 
        } 

        // Alternative method for operator * 
        public static SqlDouble Multiply(SqlDouble x, SqlDouble y) {
            return x * y;
        }
 
        // Alternative method for operator /
        public static SqlDouble Divide(SqlDouble x, SqlDouble y) { 
            return x / y; 
        }
 
        // Alternative method for operator ==
        public static SqlBoolean Equals(SqlDouble x, SqlDouble y) {
            return (x == y);
        } 

        // Alternative method for operator != 
        public static SqlBoolean NotEquals(SqlDouble x, SqlDouble y) { 
            return (x != y);
        } 

        // Alternative method for operator <
        public static SqlBoolean LessThan(SqlDouble x, SqlDouble y) {
            return (x < y); 
        }
 
        // Alternative method for operator > 
        public static SqlBoolean GreaterThan(SqlDouble x, SqlDouble y) {
            return (x > y); 
        }

        // Alternative method for operator <=
        public static SqlBoolean LessThanOrEqual(SqlDouble x, SqlDouble y) { 
            return (x <= y);
        } 
 
        // Alternative method for operator >=
        public static SqlBoolean GreaterThanOrEqual(SqlDouble x, SqlDouble y) { 
            return (x >= y);
        }

        // Alternative method for conversions. 

        public SqlBoolean ToSqlBoolean() { 
            return (SqlBoolean)this; 
        }
 
        public SqlByte ToSqlByte() {
            return (SqlByte)this;
        }
 
        public SqlInt16 ToSqlInt16() {
            return (SqlInt16)this; 
        } 

        public SqlInt32 ToSqlInt32() { 
            return (SqlInt32)this;
        }

        public SqlInt64 ToSqlInt64() { 
            return (SqlInt64)this;
        } 
 
        public SqlMoney ToSqlMoney() {
            return (SqlMoney)this; 
        }

        public SqlDecimal ToSqlDecimal() {
            return (SqlDecimal)this; 
        }
 
        public SqlSingle ToSqlSingle() { 
            return (SqlSingle)this;
        } 

        public SqlString ToSqlString() {
            return (SqlString)this;
        } 

 
 
        // IComparable
        // Compares this object to another object, returning an integer that 
        // indicates the relationship.
        // Returns a value less than zero if this < object, zero if this = object,
        // or a value greater than zero if this > object.
        // null is considered to be less than any instance. 
        // If object is not of same type, this method throws an ArgumentException.
        ///  
        ///    [To be supplied.] 
        /// 
        public int CompareTo(Object value) { 
            if (value is SqlDouble) {
                SqlDouble i = (SqlDouble)value;

                return CompareTo(i); 
            }
            throw ADP.WrongType(value.GetType(), typeof(SqlDouble)); 
        } 

        public int CompareTo(SqlDouble value) { 
            // If both Null, consider them equal.
            // Otherwise, Null is less than anything.
            if (IsNull)
                return value.IsNull ? 0  : -1; 
            else if (value.IsNull)
                return 1; 
 
            if (this < value) return -1;
            if (this > value) return 1; 
            return 0;
        }

        // Compares this instance with a specified object 
        /// 
        ///    [To be supplied.] 
        ///  
        public override bool Equals(Object value) {
            if (!(value is SqlDouble)) { 
                return false;
            }

            SqlDouble i = (SqlDouble)value; 

            if (i.IsNull || IsNull) 
                return (i.IsNull && IsNull); 
            else
                return (this == i).Value; 
        }

        // For hashing purpose
        ///  
        ///    [To be supplied.]
        ///  
        public override int GetHashCode() { 
            return IsNull ? 0 : Value.GetHashCode();
        } 

        /// 
        ///    [To be supplied.]
        ///  
        XmlSchema IXmlSerializable.GetSchema() { return null; }
 
        ///  
        ///    [To be supplied.]
        ///  
        void IXmlSerializable.ReadXml(XmlReader reader) {
            string isNull = reader.GetAttribute("nil", XmlSchema.InstanceNamespace);
            if (isNull != null && XmlConvert.ToBoolean(isNull)) {
                m_fNotNull = false; 
            }
            else { 
                m_value = XmlConvert.ToDouble(reader.ReadElementString()); 
                m_fNotNull = true;
            } 
        }

        /// 
        ///    [To be supplied.] 
        /// 
        void IXmlSerializable.WriteXml(XmlWriter writer) { 
            if (IsNull) { 
                writer.WriteAttributeString("xsi", "nil", XmlSchema.InstanceNamespace, "true");
            } 
            else {
                writer.WriteString(XmlConvert.ToString(m_value));
            }
        } 

        ///  
        ///    [To be supplied.] 
        /// 
        public static XmlQualifiedName GetXsdType(XmlSchemaSet schemaSet) { 
            return new XmlQualifiedName("double", XmlSchema.Namespace);
        }

        ///  
        ///    [To be supplied.]
        ///  
        public static readonly SqlDouble Null       = new SqlDouble(true); 
        /// 
        ///    [To be supplied.] 
        /// 
        public static readonly SqlDouble Zero       = new SqlDouble(0.0);
        /// 
        ///    [To be supplied.] 
        /// 
        public static readonly SqlDouble MinValue   = new SqlDouble(Double.MinValue); 
        ///  
        ///    [To be supplied.]
        ///  
        public static readonly SqlDouble MaxValue   = new SqlDouble(Double.MaxValue);

    } // SqlDouble
 
} // namespace System.Data.SqlTypes

// File provided for Reference Use Only by Microsoft Corporation (c) 2007.
// Copyright (c) Microsoft Corporation. All rights reserved.
                        

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