scala - 制作经过 sanitizer 的字符串类型时的对称相等(使用 scala.Proxy)

Question

我有一个 scala (2.10.4) 应用程序，其中电子邮件地址被传递了很多，我想实现一个在 IO 调用的抽象，以“清理”已经验证的电子邮件地址。

使用 scala.Proxy几乎是我想要的，但我遇到了不对称平等的问题。

    class SanitizedEmailAddress(s: String) extends Proxy with Ordered[SanitizedEmailAddress] {
  val self: String = s.toLowerCase.trim

  def compare(that: SanitizedEmailAddress) = self compareTo that.self
}

object SanitizedEmailAddress {
  def apply(s: String) = new SanitizedEmailAddress(s)
  implicit def sanitize(s: String): SanitizedEmailAddress = new SanitizedEmailAddress(s)
  implicit def underlying(e: SanitizedEmailAddress): String = e.self
}

我想要

val sanitizedEmail = SanitizedEmailAddress("Blah@Blah.com")
val expected = "blah@blah.com"
assert(sanitizedEmail == expected) // => true
assert(expected == sanitizedEmail) // => true, but this currently returns false :(

或具有类似功能的东西。有没有什么不麻烦的方法来做到这一点？

    assert(sanitizedEmail.self == expected) // => true (but pretty bad, and someone will forget)
// can have a custom equality method and use the "pimp-my-lib" pattern on strings, but then we have to remember to use that method every time

谢谢你的帮助。

Answer 1

我认为这不可能，抱歉。

我也不确定想要那个是否正确。如果 String真正等于 SanitizedEmailAddress ，那么 SanitizedEmailAddress 是什么意思？包装实际上表示？

我认为拥有 String 会更一致无法与 SanitizedEmailAddress 相提并论，并要求用户在比较之前“清理”输入。