56 lines
1.2 KiB
ObjectPascal
56 lines
1.2 KiB
ObjectPascal
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program sortThreeVariables(output);
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type
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{ this Extended Pascal data type may hold up to 25 `char` values }
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line = string(25);
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{ this procedure sorts two lines }
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procedure sortLines(var X, Y: line);
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{ nested procedure allocates space for Z only if needed }
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procedure swap;
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var
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Z: line;
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begin
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Z := X;
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X := Y;
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Y := Z
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end;
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begin
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{ for lexical sorting write `if GT(X, Y) then` }
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if X > Y then
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begin
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swap
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end
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end;
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{ sorts three line variables’s values }
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procedure sortThreeLines(var X, Y, Z: line);
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begin
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{ `var` parameters can be modified at the calling site }
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sortLines(X, Y);
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sortLines(X, Z);
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sortLines(Y, Z)
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end;
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{ writes given lines on output preceded by `X = `, `Y = ` and `Z = ` }
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procedure printThreeLines(protected X, Y, Z: line);
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begin
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{ `protected` parameters cannot be overwritten }
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writeLn('X = ', X);
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writeLn('Y = ', Y);
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writeLn('Z = ', Z)
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end;
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{ === MAIN ============================================================= }
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var
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A, B: line;
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{ for demonstration purposes: alternative method to initialize }
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C: line value '(from the "Wizard of OZ")';
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begin
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A := 'lions, tigers, and';
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B := 'bears, oh my!';
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sortThreeLines(A, B, C);
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printThreeLines(A, B, C)
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end.
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