Michael Schimmel
82 lines
1.8 KiB
ObjectPascal
82 lines
1.8 KiB
ObjectPascal
unit Myc.Lazy;
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interface
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uses
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System.SysUtils,
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Myc.Signals;
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type
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IMycLazy<T> = interface
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{$REGION 'property access'}
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function GetChanged: IMycState;
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{$ENDREGION}
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function Pop( out Res: T ): Boolean;
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property Changed: IMycState read GetChanged;
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end;
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TLazy<T> = record
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private
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FLazy: IMycLazy<T>;
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function GetChanged: IMycState; inline;
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class var
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FNull: IMycLazy<T>;
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class constructor CreateClass;
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public
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constructor Create( const ALazy: IMycLazy<T> );
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class function Construct( const Changing: IMycState; const Proc: TFunc<T> ): IMycLazy<T>; static;
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class operator Implicit( const A: IMycLazy<T> ): TLazy<T>; overload;
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class operator Implicit( const A: TLazy<T> ): IMycLazy<T>; overload;
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function Pop( out Res: T ): Boolean; inline;
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property Changed: IMycState read GetChanged;
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end;
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implementation
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uses
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Myc.Core.Lazy;
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constructor TLazy<T>.Create( const ALazy: IMycLazy<T> );
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begin
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FLazy := ALazy;
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if not Assigned( FLazy ) then
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FLazy := FNull;
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end;
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class function TLazy<T>.Construct( const Changing: IMycState; const Proc: TFunc<T> ): IMycLazy<T>;
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begin
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Result := TMycFuncLazy<T>.Create( Changing, Proc );
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end;
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class constructor TLazy<T>.CreateClass;
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begin
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FNull := TMycNullLazy<T>.Create;
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end;
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function TLazy<T>.GetChanged: IMycState;
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begin
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Result := FLazy.Changed;
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end;
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function TLazy<T>.Pop( out Res: T ): Boolean;
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begin
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Result := FLazy.Pop( Res );
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end;
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class operator TLazy<T>.Implicit( const A: IMycLazy<T> ): TLazy<T>;
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begin
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Result.Create( A );
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end;
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class operator TLazy<T>.Implicit( const A: TLazy<T> ): IMycLazy<T>;
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begin
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Result := A.FLazy;
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end;
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end.
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