146 lines
3.4 KiB
ObjectPascal
146 lines
3.4 KiB
ObjectPascal
unit Myc.Data.Types.Float;
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interface
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uses
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System.SysUtils,
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Myc.Data.Types;
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type
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// Implements the float data type.
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TImplDataFloatType = class(TInterfacedObject, IDataType, IDataFloatType)
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strict private
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class var
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FSingleton: IDataFloatType;
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FZero: IDataFloatValue;
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FNaN: IDataFloatValue;
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class constructor CreateClass;
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public
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function GetName: String;
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function GetKind: TDataKind;
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function CreateValue(Init: Double): IDataFloatValue;
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class property Singleton: IDataFloatType read FSingleton;
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end;
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implementation
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uses
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System.Math;
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type
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// Implements the float data value.
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TImplDataFloatValue = class(TInterfacedObject, IDataValue, IDataFloatValue)
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private
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FValue: Double;
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public
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constructor Create(const AValue: Double);
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// IDataValue
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function GetDataType: IDataType;
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function GetAsString: string;
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// IDataFloatValue
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function GetValue: Double;
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end;
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// Special implementation for the value 0.0 (Singleton)
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TImplDataFloatValueZero = class(TInterfacedObject, IDataValue, IDataFloatValue)
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public
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function GetDataType: IDataType;
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function GetAsString: string;
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function GetValue: Double;
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end;
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// Special implementation for NaN (Not a Number) (Singleton)
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TImplDataFloatValueNaN = class(TInterfacedObject, IDataValue, IDataFloatValue)
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public
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function GetDataType: IDataType;
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function GetAsString: string;
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function GetValue: Double;
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end;
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{ TImplDataFloatValue }
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constructor TImplDataFloatValue.Create(const AValue: Double);
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begin
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inherited Create;
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FValue := AValue;
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end;
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function TImplDataFloatValue.GetDataType: IDataType;
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begin
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Result := TImplDataFloatType.Singleton;
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end;
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function TImplDataFloatValue.GetAsString: string;
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begin
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Result := FloatToStr(FValue);
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end;
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function TImplDataFloatValue.GetValue: Double;
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begin
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Result := FValue;
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end;
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function TImplDataFloatValueZero.GetAsString: string;
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begin
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Result := '0';
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end;
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function TImplDataFloatValueZero.GetDataType: IDataType;
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begin
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Result := TImplDataFloatType.Singleton;
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end;
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function TImplDataFloatValueZero.GetValue: Double;
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begin
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Result := 0.0;
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end;
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function TImplDataFloatValueNaN.GetAsString: string;
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begin
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Result := 'NaN';
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end;
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function TImplDataFloatValueNaN.GetDataType: IDataType;
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begin
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Result := TImplDataFloatType.Singleton;
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end;
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function TImplDataFloatValueNaN.GetValue: Double;
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begin
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Result := NaN;
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end;
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{ TImplDataFloatType }
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class constructor TImplDataFloatType.CreateClass;
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begin
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FSingleton := TImplDataFloatType.Create;
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FZero := TImplDataFloatValueZero.Create;
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FNaN := TImplDataFloatValueNaN.Create;
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end;
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function TImplDataFloatType.GetName: String;
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begin
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Result := 'Float';
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end;
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function TImplDataFloatType.GetKind: TDataKind;
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begin
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Result := dkFloat;
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end;
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function TImplDataFloatType.CreateValue(Init: Double): IDataFloatValue;
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begin
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// Return singleton instances for 0.0 and NaN to avoid unnecessary allocations.
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if (Init = 0.0) then
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Result := FZero
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else if IsNaN(Init) then
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Result := FNaN
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else
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Result := TImplDataFloatValue.Create(Init);
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end;
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end.
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