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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.CodeAnalysis;
using System.Globalization;
using System.Runtime.InteropServices;
using System.Xml;
using System.Xml.Schema;
using System.Xml.Serialization;
namespace System.Data.SqlTypes
{
/// <summary>
/// Represents a floating point number within the range of -3.40E +38 through
/// 3.40E +38 to be stored in or retrieved from a database.
/// </summary>
[StructLayout(LayoutKind.Sequential)]
[XmlSchemaProvider("GetXsdType")]
public struct SqlSingle : INullable, IComparable, IXmlSerializable, IEquatable<SqlSingle>
{
private bool _fNotNull; // false if null
private float _value;
// constructor
// construct a Null
private SqlSingle(bool _)
{
_fNotNull = false;
_value = (float)0.0;
}
public SqlSingle(float value)
{
if (!float.IsFinite(value))
{
throw new OverflowException(SQLResource.ArithOverflowMessage);
}
else
{
_fNotNull = true;
_value = value;
}
}
public SqlSingle(double value) : this(checked((float)value))
{
}
// INullable
public bool IsNull
{
get { return !_fNotNull; }
}
// property: Value
public float Value
{
get
{
if (_fNotNull)
return _value;
else
throw new SqlNullValueException();
}
}
// Implicit conversion from float to SqlSingle
public static implicit operator SqlSingle(float x)
{
return new SqlSingle(x);
}
// Explicit conversion from SqlSingle to float. Throw exception if x is Null.
public static explicit operator float(SqlSingle x)
{
return x.Value;
}
public override string ToString()
{
return IsNull ? SQLResource.NullString : _value.ToString((IFormatProvider)null!);
}
public static SqlSingle Parse(string s)
{
if (s == SQLResource.NullString)
return SqlSingle.Null;
else
return new SqlSingle(float.Parse(s, CultureInfo.InvariantCulture));
}
// Unary operators
public static SqlSingle operator -(SqlSingle x)
{
return x.IsNull ? Null : new SqlSingle(-x._value);
}
// Binary operators
// Arithmetic operators
public static SqlSingle operator +(SqlSingle x, SqlSingle y)
{
if (x.IsNull || y.IsNull)
return Null;
float value = x._value + y._value;
if (float.IsInfinity(value))
throw new OverflowException(SQLResource.ArithOverflowMessage);
return new SqlSingle(value);
}
public static SqlSingle operator -(SqlSingle x, SqlSingle y)
{
if (x.IsNull || y.IsNull)
return Null;
float value = x._value - y._value;
if (float.IsInfinity(value))
throw new OverflowException(SQLResource.ArithOverflowMessage);
return new SqlSingle(value);
}
public static SqlSingle operator *(SqlSingle x, SqlSingle y)
{
if (x.IsNull || y.IsNull)
return Null;
float value = x._value * y._value;
if (float.IsInfinity(value))
throw new OverflowException(SQLResource.ArithOverflowMessage);
return new SqlSingle(value);
}
public static SqlSingle operator /(SqlSingle x, SqlSingle y)
{
if (x.IsNull || y.IsNull)
return Null;
if (y._value == (float)0.0)
throw new DivideByZeroException(SQLResource.DivideByZeroMessage);
float value = x._value / y._value;
if (float.IsInfinity(value))
throw new OverflowException(SQLResource.ArithOverflowMessage);
return new SqlSingle(value);
}
// Implicit conversions
// Implicit conversion from SqlBoolean to SqlSingle
public static explicit operator SqlSingle(SqlBoolean x)
{
return x.IsNull ? Null : new SqlSingle(x.ByteValue);
}
// Implicit conversion from SqlByte to SqlSingle
public static implicit operator SqlSingle(SqlByte x)
{
// Will not overflow
return x.IsNull ? Null : new SqlSingle(x.Value);
}
// Implicit conversion from SqlInt16 to SqlSingle
public static implicit operator SqlSingle(SqlInt16 x)
{
// Will not overflow
return x.IsNull ? Null : new SqlSingle(x.Value);
}
// Implicit conversion from SqlInt32 to SqlSingle
public static implicit operator SqlSingle(SqlInt32 x)
{
// Will not overflow
return x.IsNull ? Null : new SqlSingle(x.Value);
}
// Implicit conversion from SqlInt64 to SqlSingle
public static implicit operator SqlSingle(SqlInt64 x)
{
// Will not overflow
return x.IsNull ? Null : new SqlSingle(x.Value);
}
// Implicit conversion from SqlMoney to SqlSingle
public static implicit operator SqlSingle(SqlMoney x)
{
return x.IsNull ? Null : new SqlSingle(x.ToDouble());
}
// Implicit conversion from SqlDecimal to SqlSingle
public static implicit operator SqlSingle(SqlDecimal x)
{
// Will not overflow
return x.IsNull ? Null : new SqlSingle(x.ToDouble());
}
// Explicit conversions
// Explicit conversion from SqlDouble to SqlSingle
public static explicit operator SqlSingle(SqlDouble x)
{
return x.IsNull ? Null : new SqlSingle(x.Value);
}
// Explicit conversion from SqlString to SqlSingle
// Throws FormatException or OverflowException if necessary.
public static explicit operator SqlSingle(SqlString x)
{
if (x.IsNull)
return SqlSingle.Null;
return Parse(x.Value);
}
// Overloading comparison operators
public static SqlBoolean operator ==(SqlSingle x, SqlSingle y)
{
return (x.IsNull || y.IsNull) ? SqlBoolean.Null : new SqlBoolean(x._value == y._value);
}
public static SqlBoolean operator !=(SqlSingle x, SqlSingle y)
{
return !(x == y);
}
public static SqlBoolean operator <(SqlSingle x, SqlSingle y)
{
return (x.IsNull || y.IsNull) ? SqlBoolean.Null : new SqlBoolean(x._value < y._value);
}
public static SqlBoolean operator >(SqlSingle x, SqlSingle y)
{
return (x.IsNull || y.IsNull) ? SqlBoolean.Null : new SqlBoolean(x._value > y._value);
}
public static SqlBoolean operator <=(SqlSingle x, SqlSingle y)
{
return (x.IsNull || y.IsNull) ? SqlBoolean.Null : new SqlBoolean(x._value <= y._value);
}
public static SqlBoolean operator >=(SqlSingle x, SqlSingle y)
{
return (x.IsNull || y.IsNull) ? SqlBoolean.Null : new SqlBoolean(x._value >= y._value);
}
//--------------------------------------------------
// Alternative methods for overloaded operators
//--------------------------------------------------
// Alternative method for operator +
public static SqlSingle Add(SqlSingle x, SqlSingle y)
{
return x + y;
}
// Alternative method for operator -
public static SqlSingle Subtract(SqlSingle x, SqlSingle y)
{
return x - y;
}
// Alternative method for operator *
public static SqlSingle Multiply(SqlSingle x, SqlSingle y)
{
return x * y;
}
// Alternative method for operator /
public static SqlSingle Divide(SqlSingle x, SqlSingle y)
{
return x / y;
}
// Alternative method for operator ==
public static SqlBoolean Equals(SqlSingle x, SqlSingle y)
{
return (x == y);
}
// Alternative method for operator !=
public static SqlBoolean NotEquals(SqlSingle x, SqlSingle y)
{
return (x != y);
}
// Alternative method for operator <
public static SqlBoolean LessThan(SqlSingle x, SqlSingle y)
{
return (x < y);
}
// Alternative method for operator >
public static SqlBoolean GreaterThan(SqlSingle x, SqlSingle y)
{
return (x > y);
}
// Alternative method for operator <=
public static SqlBoolean LessThanOrEqual(SqlSingle x, SqlSingle y)
{
return (x <= y);
}
// Alternative method for operator >=
public static SqlBoolean GreaterThanOrEqual(SqlSingle x, SqlSingle y)
{
return (x >= y);
}
// Alternative method for conversions.
public SqlBoolean ToSqlBoolean()
{
return (SqlBoolean)this;
}
public SqlByte ToSqlByte()
{
return (SqlByte)this;
}
public SqlDouble ToSqlDouble()
{
return 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 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 SqlSingle i)
{
return CompareTo(i);
}
throw ADP.WrongType(value!.GetType(), typeof(SqlSingle));
}
public int CompareTo(SqlSingle 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
public override bool Equals([NotNullWhen(true)] object? value) =>
value is SqlSingle 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(SqlSingle 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();
_fNotNull = false;
}
else
{
_value = XmlConvert.ToSingle(reader.ReadElementString());
_fNotNull = true;
}
}
void IXmlSerializable.WriteXml(XmlWriter writer)
{
if (IsNull)
{
writer.WriteAttributeString("xsi", "nil", XmlSchema.InstanceNamespace, "true");
}
else
{
writer.WriteString(XmlConvert.ToString(_value));
}
}
public static XmlQualifiedName GetXsdType(XmlSchemaSet schemaSet)
{
return new XmlQualifiedName("float", XmlSchema.Namespace);
}
public static readonly SqlSingle Null = new SqlSingle(true);
public static readonly SqlSingle Zero = new SqlSingle((float)0.0);
public static readonly SqlSingle MinValue = new SqlSingle(float.MinValue);
public static readonly SqlSingle MaxValue = new SqlSingle(float.MaxValue);
} // SqlSingle
} // namespace System.Data.SqlTypes
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