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// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
using System.Data.Common;
using System.Diagnostics;
using System.Diagnostics.CodeAnalysis;
using System.Runtime.InteropServices;
using System.Xml;
using System.Xml.Schema;
using System.Xml.Serialization;
namespace System.Data.SqlTypes
{
/// <summary>
/// Represents an integer value that is either 1 or 0.
/// </summary>
[Serializable]
[StructLayout(LayoutKind.Sequential)]
[XmlSchemaProvider("GetXsdType")]
[System.Runtime.CompilerServices.TypeForwardedFrom("System.Data, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089")]
public struct SqlBoolean : INullable, IComparable, IXmlSerializable, IEquatable<SqlBoolean>
{
// m_value: 2 (true), 1 (false), 0 (unknown/Null)
private byte m_value; // Do not rename (binary serialization)
private const byte x_Null = 0;
private const byte x_False = 1;
private const byte x_True = 2;
// constructor
/// <summary>
/// Initializes a new instance of the <see cref='SqlBoolean'/> class.
/// </summary>
public SqlBoolean(bool value)
{
m_value = value ? x_True : x_False;
}
public SqlBoolean(int value) : this(value, false)
{
}
private SqlBoolean(int value, bool fNull)
{
if (fNull)
m_value = x_Null;
else
m_value = (value != 0) ? x_True : x_False;
}
// INullable
/// <summary>
/// Gets whether the current <see cref='Value'/> is <see cref='SqlBoolean.Null'/>.
/// </summary>
public bool IsNull
{
get { return m_value == x_Null; }
}
// property: Value
/// <summary>
/// Gets or sets the <see cref='SqlBoolean'/> to be <see langword='true'/> or <see langword='false'/>.
/// </summary>
public bool Value
{
get
{
return m_value switch
{
x_True => true,
x_False => false,
_ => throw new SqlNullValueException(),
};
}
}
/// <summary>
/// Gets whether the current <see cref='Value'/> is <see cref='SqlBoolean.True'/>.
/// </summary>
public bool IsTrue
{
get { return m_value == x_True; }
}
/// <summary>
/// Gets whether the current <see cref='Value'/> is <see cref='SqlBoolean.False'/>.
/// </summary>
public bool IsFalse
{
get { return m_value == x_False; }
}
// Implicit conversion from bool to SqlBoolean
/// <summary>
/// Converts a boolean to a <see cref='SqlBoolean'/>.
/// </summary>
public static implicit operator SqlBoolean(bool x)
{
return new SqlBoolean(x);
}
// Explicit conversion from SqlBoolean to bool. Throw exception if x is Null.
/// <summary>
/// Converts a <see cref='SqlBoolean'/> to a boolean.
/// </summary>
public static explicit operator bool(SqlBoolean x)
{
return x.Value;
}
// Unary operators
/// <summary>
/// Performs a NOT operation on a <see cref='SqlBoolean'/>.
/// </summary>
public static SqlBoolean operator !(SqlBoolean x)
{
switch (x.m_value)
{
case x_True:
return SqlBoolean.False;
case x_False:
return SqlBoolean.True;
default:
Debug.Assert(x.m_value == x_Null);
return SqlBoolean.Null;
}
}
public static bool operator true(SqlBoolean x)
{
return x.IsTrue;
}
public static bool operator false(SqlBoolean x)
{
return x.IsFalse;
}
// Binary operators
/// <summary>
/// Performs a bitwise AND operation on two instances of <see cref='SqlBoolean'/>.
/// </summary>
public static SqlBoolean operator &(SqlBoolean x, SqlBoolean y)
{
if (x.m_value == x_False || y.m_value == x_False)
return SqlBoolean.False;
else if (x.m_value == x_True && y.m_value == x_True)
return SqlBoolean.True;
else
return SqlBoolean.Null;
}
/// <summary>
/// Performs a bitwise OR operation on two instances of a <see cref='SqlBoolean'/>.
/// </summary>
public static SqlBoolean operator |(SqlBoolean x, SqlBoolean y)
{
if (x.m_value == x_True || y.m_value == x_True)
return SqlBoolean.True;
else if (x.m_value == x_False && y.m_value == x_False)
return SqlBoolean.False;
else
return SqlBoolean.Null;
}
// property: ByteValue
public byte ByteValue
{
get
{
if (!IsNull)
return (m_value == x_True) ? (byte)1 : (byte)0;
else
throw new SqlNullValueException();
}
}
public override string ToString()
{
return IsNull ? SQLResource.NullString : Value.ToString();
}
public static SqlBoolean Parse(string s)
{
if (null == s)
// Let Boolean.Parse throw exception
return new SqlBoolean(bool.Parse(s!));
if (s == SQLResource.NullString)
return SqlBoolean.Null;
s = s.TrimStart();
char wchFirst = s[0];
if (char.IsNumber(wchFirst) || ('-' == wchFirst) || ('+' == wchFirst))
{
return new SqlBoolean(int.Parse(s, null));
}
else
{
return new SqlBoolean(bool.Parse(s));
}
}
// Unary operators
public static SqlBoolean operator ~(SqlBoolean x)
{
return (!x);
}
// Binary operators
public static SqlBoolean operator ^(SqlBoolean x, SqlBoolean y)
{
return (x.IsNull || y.IsNull) ? Null : new SqlBoolean(x.m_value != y.m_value);
}
// Implicit conversions
// Explicit conversions
// Explicit conversion from SqlByte to SqlBoolean
public static explicit operator SqlBoolean(SqlByte x)
{
return x.IsNull ? Null : new SqlBoolean(x.Value != 0);
}
// Explicit conversion from SqlInt16 to SqlBoolean
public static explicit operator SqlBoolean(SqlInt16 x)
{
return x.IsNull ? Null : new SqlBoolean(x.Value != 0);
}
// Explicit conversion from SqlInt32 to SqlBoolean
public static explicit operator SqlBoolean(SqlInt32 x)
{
return x.IsNull ? Null : new SqlBoolean(x.Value != 0);
}
// Explicit conversion from SqlInt64 to SqlBoolean
public static explicit operator SqlBoolean(SqlInt64 x)
{
return x.IsNull ? Null : new SqlBoolean(x.Value != 0);
}
// Explicit conversion from SqlDouble to SqlBoolean
public static explicit operator SqlBoolean(SqlDouble x)
{
return x.IsNull ? Null : new SqlBoolean(x.Value != 0.0);
}
// Explicit conversion from SqlSingle to SqlBoolean
public static explicit operator SqlBoolean(SqlSingle x)
{
return x.IsNull ? Null : new SqlBoolean(x.Value != 0.0);
}
// Explicit conversion from SqlMoney to SqlBoolean
public static explicit operator SqlBoolean(SqlMoney x)
{
return x.IsNull ? Null : (x != SqlMoney.Zero);
}
// Explicit conversion from SqlDecimal to SqlBoolean
public static explicit operator SqlBoolean(SqlDecimal x)
{
return x.IsNull ? SqlBoolean.Null : new SqlBoolean(x._data1 != 0 || x._data2 != 0 ||
x._data3 != 0 || x._data4 != 0);
}
// Explicit conversion from SqlString to SqlBoolean
// Throws FormatException or OverflowException if necessary.
public static explicit operator SqlBoolean(SqlString x)
{
return x.IsNull ? Null : SqlBoolean.Parse(x.Value);
}
// Overloading comparison operators
public static SqlBoolean operator ==(SqlBoolean x, SqlBoolean y)
{
return (x.IsNull || y.IsNull) ? SqlBoolean.Null : new SqlBoolean(x.m_value == y.m_value);
}
public static SqlBoolean operator !=(SqlBoolean x, SqlBoolean y)
{
return !(x == y);
}
public static SqlBoolean operator <(SqlBoolean x, SqlBoolean y)
{
return (x.IsNull || y.IsNull) ? SqlBoolean.Null : new SqlBoolean(x.m_value < y.m_value);
}
public static SqlBoolean operator >(SqlBoolean x, SqlBoolean y)
{
return (x.IsNull || y.IsNull) ? SqlBoolean.Null : new SqlBoolean(x.m_value > y.m_value);
}
public static SqlBoolean operator <=(SqlBoolean x, SqlBoolean y)
{
return (x.IsNull || y.IsNull) ? SqlBoolean.Null : new SqlBoolean(x.m_value <= y.m_value);
}
public static SqlBoolean operator >=(SqlBoolean x, SqlBoolean 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 SqlBoolean OnesComplement(SqlBoolean x)
{
return ~x;
}
// Alternative method for operator &
public static SqlBoolean And(SqlBoolean x, SqlBoolean y)
{
return x & y;
}
// Alternative method for operator |
public static SqlBoolean Or(SqlBoolean x, SqlBoolean y)
{
return x | y;
}
// Alternative method for operator ^
public static SqlBoolean Xor(SqlBoolean x, SqlBoolean y)
{
return x ^ y;
}
// Alternative method for operator ==
public static SqlBoolean Equals(SqlBoolean x, SqlBoolean y)
{
return (x == y);
}
// Alternative method for operator !=
public static SqlBoolean NotEquals(SqlBoolean x, SqlBoolean y)
{
return (x != y);
}
// Alternative method for operator >
public static SqlBoolean GreaterThan(SqlBoolean x, SqlBoolean y)
{
return (x > y);
}
// Alternative method for operator <
public static SqlBoolean LessThan(SqlBoolean x, SqlBoolean y)
{
return (x < y);
}
// Alternative method for operator <=
public static SqlBoolean GreaterThanOrEquals(SqlBoolean x, SqlBoolean y)
{
return (x >= y);
}
// Alternative method for operator !=
public static SqlBoolean LessThanOrEquals(SqlBoolean x, SqlBoolean y)
{
return (x <= y);
}
// Alternative method for conversions.
public SqlByte ToSqlByte()
{
return (SqlByte)this;
}
public SqlDouble ToSqlDouble()
{
return (SqlDouble)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.
public int CompareTo(object? value)
{
if (value is SqlBoolean i)
{
return CompareTo(i);
}
throw ADP.WrongType(value!.GetType(), typeof(SqlBoolean));
}
public int CompareTo(SqlBoolean 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 (ByteValue < value.ByteValue) return -1;
if (ByteValue > value.ByteValue) return 1;
return 0;
}
// Compares this instance with a specified object
public override bool Equals([NotNullWhen(true)] object? value) =>
value is SqlBoolean other && Equals(other);
/// <summary>Indicates whether the current instance is equal to another instance of the same type.</summary>
/// <param name="other">An instance to compare with this instance.</param>
/// <returns>true if the current instance is equal to the other instance; otherwise, false.</returns>
public bool Equals(SqlBoolean other) =>
other.IsNull || IsNull ? other.IsNull && IsNull :
(this == other).Value;
// For hashing purpose
public override int GetHashCode() => IsNull ? 0 : Value.GetHashCode();
XmlSchema? IXmlSerializable.GetSchema() { return null; }
void IXmlSerializable.ReadXml(XmlReader reader)
{
string? isNull = reader.GetAttribute("nil", XmlSchema.InstanceNamespace);
if (isNull != null && XmlConvert.ToBoolean(isNull))
{
// Read the next value.
reader.ReadElementString();
m_value = x_Null;
}
else
{
m_value = XmlConvert.ToBoolean(reader.ReadElementString()) ? x_True : x_False;
}
}
void IXmlSerializable.WriteXml(XmlWriter writer)
{
if (IsNull)
{
writer.WriteAttributeString("xsi", "nil", XmlSchema.InstanceNamespace, "true");
}
else
{
writer.WriteString(m_value == x_True ? "true" : "false");
}
}
public static XmlQualifiedName GetXsdType(XmlSchemaSet schemaSet)
{
return new XmlQualifiedName("boolean", XmlSchema.Namespace);
}
/// <summary>
/// Represents a true value that can be assigned to the
/// <see cref='Value'/> property of an instance of the <see cref='SqlBoolean'/> class.
/// </summary>
public static readonly SqlBoolean True = new SqlBoolean(true);
/// <summary>
/// Represents a false value that can be assigned to the <see cref='Value'/> property of an instance of
/// the <see cref='SqlBoolean'/> class.
/// </summary>
public static readonly SqlBoolean False = new SqlBoolean(false);
/// <summary>
/// Represents a null value that can be assigned to the <see cref='Value'/> property of an instance of
/// the <see cref='SqlBoolean'/> class.
/// </summary>
public static readonly SqlBoolean Null = new SqlBoolean(0, true);
public static readonly SqlBoolean Zero = new SqlBoolean(0);
public static readonly SqlBoolean One = new SqlBoolean(1);
} // SqlBoolean
} // namespace System.Data.SqlTypes
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