15 lines
208 B
Plaintext
15 lines
208 B
Plaintext
pub fn map(opt: Option<a>, f: fn(a) -> b) -> Option<b> {
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when opt is {
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None -> None
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Some(a) -> Some(f(a))
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}
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}
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fn add_one(n: Int) -> Int {
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n + 1
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}
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test map_1() {
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map(None, add_one) == None
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}
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