36 lines
1.1 KiB
ObjectPascal
36 lines
1.1 KiB
ObjectPascal
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program integerness(output);
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{ determines whether a `complex` also fits in `integer` ---------------- }
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function isRealIntegral(protected x: complex): Boolean;
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begin
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{ It constitutes an error if no value for `trunc(x)` exists, }
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{ thus check re(x) is in the range -maxInt..maxInt first. }
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isRealIntegral := (im(x) = 0.0) and_then
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(abs(re(x)) <= maxInt * 1.0) and_then
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(trunc(re(x)) * 1.0 = re(x))
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end;
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{ calls isRealIntegral with zero imaginary part ------------------------ }
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function isIntegral(protected x: real): Boolean;
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begin
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isIntegral := isRealIntegral(cmplx(x * 1.0, 0.0))
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end;
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{ Rosetta code test ---------------------------------------------------- }
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procedure test(protected x: complex);
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begin
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writeLn(re(x), ' + ', im(x), ' 𝒾 : ',
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isIntegral(re(x)), ' ', isRealIntegral(x))
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end;
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{ === MAIN ============================================================= }
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begin
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test(cmplx(25.0, 0.0));
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test(cmplx(24.999999, 0.0));
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test(cmplx(25.000100, 0.0));
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test(cmplx(-2.1E120, 0.0));
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test(cmplx(-5E-2, 0.0));
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test(cmplx(5.0, 0.0));
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test(cmplx(5, -5));
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end.
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