是否可以在Scala中使用隐式转换参数来提取器（unapply）？
我创建了一个名为CaseInsensitive的类，它包装了一个字符串（请参阅实现在Scala中执行不区分大小写的比较的字符串类）。
我创建了一个case类，它有一个CaseInsensitive类型的成员变量，所以它得到一个默认的unapply方法，它提取一个CaseInsensitive类型的变量，但是我希望像这样使用它：
case class PropertyKey( val name : CaseInsensitive )
val foo = new PropertyKey("foo")
val result = foo match {
case PropertyKey("foo") => true
case _ => false
}
type mismatch;
found : java.lang.String("foo")
required: com.acme.CaseInsensitive
case class PropertyKey( val name : CaseInsensitive )
val foo = new PropertyKey("foo")
val result = foo match {
case PropertyKey(CaseInsensitive("foo")) => true
case _ => false
}
/** Used to enable us to easily index objects by string, case insensitive
*
* Note: this class preserve the case of your string!
*/
case class CaseInsensitive ( val _s : String ) extends Proxy {
require( _s != null)
val self = _s.toLowerCase
override def toString = _s
def i = this // convenience implicit conversion
}
object CaseInsensitive {
implicit def CaseInsensitive2String(c : CaseInsensitive) = if ( c == null ) null else c._s
implicit def StringToCaseInsensitive(s : String) = CaseInsensitive(s)
def fromString( s : String ) = s match {
case null => None
case _ => Some(CaseInsensitive(s))
}
}
没有找到相关结果
已邀请:
1 个回复
目浆搽
object PropertyKeyCI { def unapply(p: PropertyKey): Option[String] = Some(p.name.self) }val foo = new PropertyKey("foo") val result = foo match { case PropertyKeyCI("foo") => true case _ => false }// result == false !!!! val foo = new CaseInsensitive("Foo") val result = foo match { case CaseInsensitive("foo") => true case _ => false } val CaseInsensitive(s) = "aBcDeF" assertFalse(s == "abcdef")