TDoubleHelper

[Properties (by Name)][Methods (by Name)][Events (by Name)]

Helper for Double floating point type

Declaration

Source position: syshelph.inc line 263

Type
  TDoubleHelper = type helper type for Double
  private
    function GetB(AIndex: Cardinal) : Byte;
    function GetW(AIndex: Cardinal) : Word;
    function GetE : QWord;
    function GetF : QWord;
    function GetS : Boolean;
    procedure SetB(AIndex: Cardinal; const AValue: Byte);
    procedure SetW(AIndex: Cardinal; const AValue: Word);
    procedure SetE(AValue: QWord);
    procedure SetF(AValue: QWord);
    procedure SetS(AValue: Boolean);
  public
    Epsilon : Double = 4.9406564584124654418e-324;
    MaxValue : Double = 1.7976931348623157081e+308;
    MinValue : Double = - 1.7976931348623157081e+308;
    PositiveInfinity : Double = 1.0 / 0.0;
    NegativeInfinity : Double = (- 1.0) / (0.0);
    NaN : Double = 0.0 / 0.0;
    class function IsInfinity(const AValue: Double) : Boolean;  Overload
                             ;  Static;
    function IsInfinity : Boolean;  Overload;
    class function IsNan(const AValue: Double) : Boolean;  Overload;  Static;
    function IsNan : Boolean;  Overload;
    class function IsNegativeInfinity(const AValue: Double) : Boolean
                                     ;  Overload;  Static;
    function IsNegativeInfinity : Boolean;  Overload;
    class function IsPositiveInfinity(const AValue: Double) : Boolean
                                     ;  Overload;  Static;
    function IsPositiveInfinity : Boolean;  Overload;
    class function Parse(const AString: string) : Double;  Overload;  Static;
    class function Parse(const AString: string; 
                        const AFormatSettings: TFormatSettings) : Double
                        ;  Overload;  Static;
    class function Size : Integer;  Static;
    class function ToString(const AValue: Double) : string;  Overload
                           ;  Static;
    class function ToString(const AValue: Double; 
                           const AFormat: TFloatFormat; 
                           const APrecision: Integer; 
                           const ADigits: Integer) : string;  Overload
                           ;  Static;
    class function ToString(const AValue: Double; 
                           const AFormat: TFloatFormat; 
                           const APrecision: Integer; 
                           const ADigits: Integer; 
                           const AFormatSettings: TFormatSettings) : string
                           ;  Overload;  Static;
    class function ToString(const AValue: Double; 
                           const AFormatSettings: TFormatSettings) : string
                           ;  Overload;  Static;
    function ToString(const AFormat: TFloatFormat; 
                     const APrecision: Integer; const ADigits: Integer)
                      : string;  Overload;
    function ToString(const AFormat: TFloatFormat; 
                     const APrecision: Integer; const ADigits: Integer; 
                     const AFormatSettings: TFormatSettings) : string
                     ;  Overload;
    function ToString(const AFormatSettings: TFormatSettings) : string
                     ;  Overload;
    function ToString : string;  Overload;
    class function TryParse(const AString: string; out AValue: Double)
                            : Boolean;  Overload;  Static;
    class function TryParse(const AString: string; out AValue: Double; 
                           const AFormatSettings: TFormatSettings) : Boolean
                           ;  Overload;  Static;
    procedure BuildUp(const ASignFlag: Boolean; const AMantissa: QWord; 
                     const AExponent: Integer);
    function Exponent : Integer;
    function Fraction : Extended;
    function Mantissa : QWord;
    function SpecialType : TFloatSpecial;
    Bytes[AIndex: Cardinal]: Byte;
    Words[AIndex: Cardinal]: Word;
    Sign : Boolean;
    Exp : QWord;
    Frac : QWord;
  end
  ;

Description

TDoubleHelper is the helper type for the Double-sized floating point type. It contains some conversion methods, as well as access to the low-level structure of the floating-point representation of a Double.

Members

Member	Type	Visibility	Description
BuildUp	Method	public	Build a Double-sized floating point from its composing parts
Bytes	Property	public	Indexed access to the individual bytes of the floating point value
Epsilon	Constant	public	Precision for this floating point type
Exp	Property	public	The bit pattern of the exponent as stored in memory.
Exponent	Method	public	Exponent of the floating-point value
Frac	Property	public	Bitpattern that makes up the fractional part.
Fraction	Method	public	Fraction of the floating-point value
GetB	Method	private
GetE	Method	private
GetF	Method	private
GetS	Method	private
GetW	Method	private
IsInfinity	Method	public	Check whether a value is positive or negative infinity.
IsNan	Method	public	Check whether a value equals NaN.
IsNegativeInfinity	Method	public	Check whether a value is negative infinity.
IsPositiveInfinity	Method	public	Check whether a value is positive infinity.
Mantissa	Method	public	Mantissa of the floating-point
MaxValue	Constant	public	Largest possible value for the Double floating point type
MinValue	Constant	public	Smallest (negative) possible value for the Double floating point type
NaN	Constant	public	Representation of NaN (Not a Number)
NegativeInfinity	Constant	public	Negative infinity as represented by a Double floating point type
Parse	Method	public	Convert a string to a floating point value
PositiveInfinity	Constant	public	Positive infinity as represented by a Double floating point type
SetB	Method	private
SetE	Method	private
SetF	Method	private
SetS	Method	private
SetW	Method	private
Sign	Property	public	Sign of the floating point value
Size	Method	public	Size (in bytes) of a Double-sized floating point value.
SpecialType	Method	public	Return the type of the Double-sized floating point value
ToString	Method	public	Convert a Double-sized floating point value to a string
TryParse	Method	public	Try to convert a string to a Double-sized floating point value.
Words	Property	public	Indexed access to the words that make up the floating point value

Inheritance

Class	Description
TDoubleHelper	Helper for Double floating point type

See also

Name	Description
Byte	An unsigned 8-bits integer
QWord	64-bit unsigned integer
QWord	64-bit unsigned integer
TDoubleHelper	Helper for Double floating point type
TExtendedHelper	Helper for Extended floating point type
Word	An unsigned 16-bits integer