28 lines
562 B
V
28 lines
562 B
V
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type Tree = Leaf | Node
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struct Leaf {}
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struct Node {
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value int
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left Tree
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right Tree
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}
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// NB: a match expression, infers the type of its result
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// from the type of the return value in the first branch,
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// => it needs an explicit int(0) cast here:
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fn size(tree Tree) int {
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return match tree {
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Leaf { int(0) }
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Node { 1 + size(tree.left) + size(tree.right) }
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}
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}
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fn main() {
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node1 := Node{30, Leaf{}, Leaf{}}
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node2 := Node{20, Leaf{}, Leaf{}}
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tree := Node{10, node1, node2}
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println('tree structure:\n $tree')
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println('tree size: ${size(tree)}')
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}
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