feature

Type Members

1. final class Caller[+A] extends AnyVal

   

   An implicit value that points to the function caller.

   An implicit value that points to the function caller.

   Usage

   libraryDependencies += "com.thoughtworks.feature" %% "caller" % "latest.release"

   Getting the caller for logging or something

   object Foo{
     def log()(implicit caller: Caller[Any]) = {
       println(caller.value)
     }
   }
   object Bar{
     Foo.log() // Bar
   }

   Restricting who you can be called from

   class IKnowWhatImDoing
   object Foo{
     def runDangerous()(implicit caller: Caller[IKnowWhatImDoing]) = {
       println(caller.value)
     }
   }
   object Bar {
     Foo.runDangerous() // compile error
   }
   object Bar2 extends IKnowWhatImDoing{
     Foo.runDangerous() // ok, prints Bar2
   }

   Getting calling class or classloader, e.g. for loading resources, without needing to worry about properly setting up and tearing down the Context ClassLoader

   object Foo{
     def getResource(path: String)(implicit caller: Caller[_]) = {
       caller.value.getClass.getClassLoader.getResourceAsStream(path)
     }
   }
   object Bar{
     Foo.getResource("/thing/file.txt") // loads resource from `Bar`s classloader, always
   }

   Authors:

   Li Haoyi

   杨博 (Yang Bo) <[email protected]>