查找 scala 程序使用的隐式执行上下文的 scalaways

Question

I have a scala class taking implicit execution-context parameter, in play-framework based application. At runtime of this play application, is there a way to see list of implicits(along with names) used by a class? Appreciate any input.

Answer 1

At runtime, you can summon an implicit via implicitly[T] , eg

println(implicitly[ExecutionContext])

This probably won't give you the name that context has been bound to. As for a list, well, at runtime there's at most one instance of any given type in the implicit scope at a point in time (and the same is true at compile time for a given location in the code), so a list wouldn't be much value.