Scala implicit conversion called twice -


I'm trying to institute classes of maps [string, Annie], through which some Jesan-RPC Is obtained. So I end the following problem: 

  val mpa: map [string, any] = map ("key" -> 0.0) Built-in def anyToInt (a: Any): Int = A .asInstanceOf [double] .toInt

The key is present all right 

  Val I:. Int = mpa.getOrElse ("key", 0.0) I: Int = 0

But when the key is unavailable ...: 

  scala> ; Val I: Int = mpa.getOrElse (not molded in "Val", 0.0) java.lang.Double on scala.runtime.BoxesRunTime.unboxToDouble (Unknown Source) at JavaklangkClassCastException: JavaklangkInteger KanyToInt be can (& lt; console & gt ;: 13

now, we are adding some verbiage such as: 

  implicit def anyToInt (a : Any): int = {println (a) value b = a.asInstanceOf [double] .toInt println ("changed") b}

We found:

< pre> val i: Int = mpa.getOrElse ( "VAL", 0.0) 0.0 change 0 java.lang.ClassCastException: java.lang.Integer java.lang.Double the ..... < / Pre> So I came to the conclusion that any tattoo is said twice and secondly it gets in any form.

Question:

  1. Why ?!

  2. What should I do to avoid this?

PS: Sorry, If this is a newbie question.

hidden direct conversion and especially any As it is in your case, it is a very bad idea and you know Defense is why I advise you to convert map [string Inti] to your input map. You do not need a performance here, but if you still want to go with the underlying, then you should do it with the cover: 

  built-in def anyExtender (x: Any) = new {def ToInt = x match {case x: double = & gt; X.toInt}}

and use it like this: 

  mpa.getOrElse ("val", 0.0) .toInt  < / Pre> 
 since it was like following the implementation of the underlying cover Scale 2.10: 
 
  underlying class AnyExtender (x: Any) {def toInt = x match {case x : Double = & gt; X.toInt}}  
 
 Still, your conversion function does not work on all the subtypes of  any , with  any  Expanding is such a thing that such a function would be right to increase the  double , but it is already there. 
 
  map.getOrElse ( "VAL", 0.0) .asInstanceOf [double] .toInt  <: the only way this type of situation would be just using my map conversions for > 
 updates 
 
 the map [string, ante]  will work for you, if you move the logic that you want to keep in spreading this : 
   WAL ResultsMapStringToinType = InputMapStringToAnap.MapValue {Case X: Double => X.toInt case x: string = & gt; X.toInt case x: timestamp = & gt; // ... // and so on}

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