文字列に適当な変換を行なってOptionへ格納する。 | Codetter（こーどったー）

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import java.text.{SimpleDateFormat => SDF}
val sdf = new SDF("yyyy-MM-dd'T'HH:mm:ssZ")
def convertInt(x: String) = x.toInt
def convertDate(x: String) = sdf.parse(x)
def toOption[T](x: String, converter: String => T = (str: String) => str) = {
  try {
    x match { case "" => None; case other => Some(converter(other)) } 
  } catch { 
    case e: Exception => None 
  }
}
// 使い方
scala> toOption("aaa")
res0: Option[String] = Some(aaa)
scala> toOption("123", convertInt _)
res1: Option[Int] = Some(123)
scala> toOption("2011-07-30 12:34:56", convertDate _)
res2: Option[java.util.Date] = None
scala> toOption("2011-07-30T12:34:56+0900", convertDate _)
res3: Option[java.util.Date] = Some(Sat Jul 30 12:34:56 JST 2011)
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