Polymorphic copy: Difference between revisions
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(→{{header|Ada}}: Fix modification in "07:25, 9 September 2014 rosettacode>Ker ") |
(PascalABC.NET) |
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For immutable data it usually does not make sense to clone it because it does not have an identity beyond its value. |
For immutable data it usually does not make sense to clone it because it does not have an identity beyond its value. |
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For mutable data types there are clone functions available (<code>Dictionary.clone</code>, <code>Array.clone</code>, <code>BitArray.clone</code>). |
For mutable data types there are clone functions available (<code>Dictionary.clone</code>, <code>Array.clone</code>, <code>BitArray.clone</code>). |
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=={{header|PascalABC.NET}}== |
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<syntaxhighlight lang="delphi"> |
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type |
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Base = class |
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public |
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fb: integer; |
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constructor (fb: integer) := Self.fb := fb; |
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function ToString: string; override := fb.ToString; |
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function Clone: Base; virtual := new Base(fb); |
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end; |
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Derived = class(Base) |
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public |
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fd: real; |
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constructor (fb: integer; fd: real); |
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begin |
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inherited Create(fb); |
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Self.fd := fd; |
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end; |
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function ToString: string; override := inherited ToString + ',' + fd.ToString; |
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function Clone: Base; override := new derived(fb,fd); |
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end; |
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begin |
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var lst := new List<Base>; |
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lst.Add(new Base(3)); |
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lst.Add(new Derived(4,5.5)); |
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lst.Add(new Base(6)); |
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lst.Add(new Derived(7,8.8)); |
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lst.Println; |
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var lst1 := new List<Base>; |
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foreach var obj in lst do |
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lst1.Add(obj.Clone); |
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lst1.Println; |
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end. |
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</syntaxhighlight> |
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{{out}} |
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<pre> |
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3 4,5.5 6 7,8.8 |
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3 4,5.5 6 7,8.8 |
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</pre> |
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=={{header|Perl}}== |
=={{header|Perl}}== |
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