Parametric polymorphism: Difference between revisions
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11.22 11.22 11.22</pre> |
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=={{header|Dart}}== |
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<lang dart>class TreeNode<T> { |
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T value; |
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TreeNode<T> left; |
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TreeNode<T> right; |
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TreeNode(this.value); |
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TreeNode map(T f(T t)) { |
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var node = new TreeNode(f(value)); |
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if(left != null) { |
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node.left = left.map(f); |
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} |
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if(right != null) { |
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node.right = right.map(f); |
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} |
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return node; |
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} |
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void forEach(void f(T t)) { |
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f(value); |
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if(left != null) { |
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left.forEach(f); |
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} |
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if(right != null) { |
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right.forEach(f); |
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} |
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} |
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} |
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void main() { |
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TreeNode root = new TreeNode(1); |
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root.left = new TreeNode(2); |
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root.right = new TreeNode(3); |
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root.left.right = new TreeNode(4); |
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print('first tree'); |
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root.forEach(print); |
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var newRoot = root.map((t) => t * 222); |
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print('second tree'); |
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newRoot.forEach(print); |
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}</lang> |
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{{out}} |
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<pre>first tree |
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1 |
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2 |
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4 |
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3 |
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second tree |
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222 |
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444 |
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888 |
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666</pre> |
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=={{header|E}}== |
=={{header|E}}== |
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