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24 lines
470 B
Nim
24 lines
470 B
Nim
type
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TMaybe[T] = object
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case empty: bool
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of false: value: T
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else: nil
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proc Just*[T](val: T): TMaybe[T] =
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result.empty = false
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result.value = val
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proc Nothing[T](): TMaybe[T] =
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result.empty = true
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proc safeReadLine(): TMaybe[string] =
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var r = stdin.readLine()
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if r == "": return Nothing[string]()
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else: return Just(r)
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when isMainModule:
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var Test = Just("Test")
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echo(Test.value)
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var mSomething = safeReadLine()
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echo(mSomething.value)
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