Questions tagged [classtag]
22 questions
0
votes
1 answer
What is the meaning of a generic type like "C: ClassTag : Manifest"?
I found some snippets as follow:
import org.json4s.DefaultFormats
import org.json4s.jackson.JsonMethods._
import scala.io.Source
import scala.reflect.ClassTag
class ConfigLoader[C: ClassTag : Manifest](filePath: String) {
def loadFromFile(): C…
xun yulin
- 1
- 1
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2 answers
How to initialize variable of Type in Scala?
I'm new to scala, sorry for the dumb question.
I want to remove the return statements from this Scala code (my real case is much more complicated than this)
def readValue[Type](value: Any)(implicit tag: ClassTag[Type]): Type = {
if (value ==…
elaspog
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0 answers
Converting scala list to array
When I try to do this, it works fine
val list = List(1,2,3,4,5)
val array = list.toArray
But I am trying to understand the implicits that happen behind the scenes. The signature of toArray is
[B >: Int](implicit evidence$1 : classTag[B])
Any…
Srinivas
- 2,010
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Scala get classtag from class instance
I need to write a generic method to get all fields of an object and it's value, the class of this object may contains ClassTag, so we should find a way to get it as well, is any way good way ? the difficulty is we don't know the class ahead, it may…
Jerry Wu
- 21
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0
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1 answer
No ClassTag available for A - but implicit parameter present
Using scala 2.12.4 I cannot get this code to work since it says
[error] .../src/main/scala/effect.scala:32:11: No ClassTag available for A
[error] Effect(effectDefinition)
[error] ^
[error] one error found
[error]…
winson
- 388
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- 9
0
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0 answers
Scala, ClassTag and Guice: Error injecting constructor, java.lang.StackOverflowError
In my Play 2 application, I need to create a class tag in the class which is instantiated by Guice (as an eager singleton; this is a requirement).
case class UserCreated(id: Long, userName: String) extends ApplicationEvent
@Singleton
class…
Teimuraz
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1 answer
json4s JValue scala classTag works wrong
In my code, I use classTag[JValue] want to get org.json4s.JsonAST.JValue ,
but actually it returns org.json4s.JsonAST$JValue, it is strange ! why there is the $?
I am new guy use scala ,could someone answer me ? thanks a lot
yang_song
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