Fluent Logging with Kotlin

Logger.kt

inline fun <A> A.logWith(logger: Logger, block: Logger.(A) -> Unit) : A = 
    this.also { logger.block(it) }

// With interface injection
interface HasLog {
    val log: Logger
    fun <A> A.log(block: Logger.(A) -> Unit) : A =
        logWith(logger, block)
}

Usage.kt

// manual
list.map { it.something }
  .logWith(logger) { verbose("Got this $it") }
  .map { "This is cool: $it" }

// injected

class MyClass(
  override val log : Logger
) : HasLog {
  
  fun dosomething(list: List<String>) : List<String> = 
    list.map { it.length() }
      .log { verbose("Lengths are $it") }
      .map { "I've got $it characters, but a new line ain't one" }
  
}