[Solved]-Scala multiple implicit parameters with defaults resulting in ambiguous values-scala

I think you should revisit using all these implicit unless you are doing some really funky DSL.

Here is one way to solve the problem you are having. As you may have guessed, implicit work on the Type not the name, so having two implicit with the same type is a No-No.

Since Scala 2.10, Scala allows you to "inline" classes using AnyVal (SIP-15). Here is an example of a so called value class:

case class Path(p: String) extends AnyVal

Now instead of using Strings to represent your entities you enclose them in this nice "wrapper" class. The cool thing about this is that the compiler will take care of replacing all Path objects in your code with a String during compilation time. So in terms of compiled code, you get the same performance as if you used a String. You gain a lot of type safety without paying a runtime penalty.

Now coming back to your case, here is how to solve the problem you have:

case class Path(s: String) extends AnyVal
case class BaseUrl(s: String) extends AnyVal

def foo(implicit a: Path, b: BaseUrl) = a.s ++ b.s

implicit val a: Path = Path("a")
implicit val b: BaseUrl = BaseUrl("b")

Here is how to use it:

scala> foo
res0: String = ab