77 lines
1.3 KiB
ObjectPascal
77 lines
1.3 KiB
ObjectPascal
program First_class_functions;
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{$APPTYPE CONSOLE}
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uses
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System.SysUtils,
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System.Math;
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type
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TFunctionTuple = record
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forward, backward: TFunc<Double, Double>;
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procedure Assign(forward, backward: TFunc<Double, Double>);
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end;
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TFunctionTuples = array of TFunctionTuple;
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var
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cube, croot, fsin, fcos, faSin, faCos: TFunc<Double, Double>;
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FunctionTuples: TFunctionTuples;
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ft: TFunctionTuple;
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{ TFunctionTuple }
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procedure TFunctionTuple.Assign(forward, backward: TFunc<Double, Double>);
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begin
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self.forward := forward;
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self.backward := backward;
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end;
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begin
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cube :=
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function(x: Double): Double
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begin
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result := x * x * x;
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end;
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croot :=
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function(x: Double): Double
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begin
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result := Power(x, 1 / 3.0);
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end;
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fsin :=
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function(x: Double): Double
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begin
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result := Sin(x);
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end;
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fcos :=
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function(x: Double): Double
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begin
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result := Cos(x);
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end;
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faSin :=
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function(x: Double): Double
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begin
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result := ArcSin(x);
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end;
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faCos :=
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function(x: Double): Double
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begin
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result := ArcCos(x);
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end;
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SetLength(FunctionTuples, 3);
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FunctionTuples[0].Assign(fsin, faSin);
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FunctionTuples[1].Assign(fcos, faCos);
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FunctionTuples[2].Assign(cube, croot);
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for ft in FunctionTuples do
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Writeln(ft.backward(ft.forward(0.5)):2:2);
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readln;
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end.
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