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POWeird Type Mismatch in Scala
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  1. POWeird Type Mismatch in Scala
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    copied!<p>I hope this question hasn't been answered yet somewhere else. Didn't find an answer here.</p> <p>In my localisation system I've got a class named Language</p> <pre><code>class Language(val name:String, dict:HashMap[String, String]) { def apply(key: String):String = (dict get key) match { case None =&gt; "°unknown°" case Some(s) =&gt; s } //DO SOME OTHER THINGS } </code></pre> <p>and an object named LanguageCentral</p> <pre><code>object LanguageCentral { private var lang:Option[Language] = None //SOME OTHER PRIVATE MEMBERS def language = lang def language_=(l:Option[Language]) = l match { case None =&gt; {} case Some(l) =&gt; setLanguage(l) } def setLanguage(l:Language) { lang = Some(l) //DO SOME OTHER THINGS } //DO LOTS OF OTHER THINGS } </code></pre> <p>I haven't written any code that's using this framework yet but trying it in an interactive session revealed a type error I don't really understand:</p> <pre><code>scala&gt; val l = new LanguageCreator("Languages.csv").getLanguage("English") l: Option[Language] = Some(Language@7aeb46d) scala&gt; LanguageCentral.language=l &lt;console&gt;:23: error: type mismatch; found : Option[Language] required: Option[Language] LanguageCentral.language=l ^ scala&gt; LanguageCentral setLanguage (l getOrElse null) &lt;console&gt;:24: error: type mismatch; found : Language required: Language LanguageCentral setLanguage (l getOrElse null) ^ </code></pre> <p>I really don't have a clue what's wrong. But from my experience with Haskell I guess that the solution is only a minor change away.;)<br> Could somebody help me? Thx.</p> <p>P.S.: using Scala 2.8.0.final</p>
 

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