避免在Scala中隐式定义歧义

本文介绍了避免在Scala中隐式定义歧义的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我正在尝试创建从任何类型(例如Int)到字符串的隐式转换...

I am trying to create an implicit conversion from any type (say, Int) to a String...

隐式转换为String意味着RichString方法(如反向)不可用.

An implicit conversion to String means RichString methods (like reverse) are not available.

implicit def intToString(i: Int) = String.valueOf(i) 100.toCharArray // => Array[Char] = Array(1, 0, 0) 100.reverse // => error: value reverse is not a member of Int 100.length // => 3

对RichString的隐式转换意味着String方法(如toCharArray)不可用

An implicit conversion to RichString means String methods (like toCharArray) are not available

implicit def intToRichString(i: Int) = new RichString(String.valueOf(i)) 100.reverse // => "001" 100.toCharArray // => error: value toCharArray is not a member of Int 100.length // => 3

同时使用两个隐式转换意味着重复的方法(如长度)是不明确的.

Using both implicit conversions means duplicated methods (like length) are ambiguous.

implicit def intToString(i: Int) = String.valueOf(i) implicit def intToRichString(i: Int) = new RichString(String.valueOf(i)) 100.toCharArray // => Array[Char] = Array(1, 0, 0) 100.reverse // => "001" 100.length // => both method intToString in object $iw of type // (Int)java.lang.String and method intToRichString in object // $iw of type (Int)scala.runtime.RichString are possible // conversion functions from Int to ?{val length: ?}

那么，是否可以隐式转换为String并仍然支持所有String和RichString方法?

So, is it possible to implicitly convert to String and still support all String and RichString methods?

推荐答案

要么建立一个庞大的代理类，要么吸纳它，并要求客户端消除歧义:

Either make a huge proxy class, or suck it up and require the client to disambiguate it:

100.asInstanceOf [String] .length

100.asInstanceOf[String].length