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scalaakka-http

Where does this akka-http test import Marshaller?

I am looking at this akka-http docs example (which links to akka-http test code):

Marshalling

This is actually a test from github code MarshalSpec.scala. My question is, where is the implicit Marshaller imported here? I am looking at imports, and I couldn't find it? I tried using IntelliJ to show me implicit imports, but I still couldn't figure this out. Where is the import statement that gets the implicit declaration for a Marshaller that is passed to:

  val entityFuture = Marshal(string).to[MessageEntity]

at line 21? It calls 

def to[B](implicit m: Marshaller[A, B], ec: ExecutionContext): Future[B] =

in Marshal.scala and passes an implicit m: Marshaller, which I can't pinpoint.

Solution

  • Marshaller extends PredefinedToEntityMarshallers , which provides marshalling from String.

    But, why does Marshaller comes with its own implicits ? It's because scala search for implicits in the implicit scope of type arguments : Where does Scala look for implicits?

    So, Marshaller comes with its own Marshallers ready to use :)