Logger with Boolean result on logging methods

gistfile1.scala

// With Boolean as a return type you get nice compose-ability semantics.
// With Unit (void for Java) return type, you only get ugly if()s.

trait Logger {
  def isDebugEnabled: Boolean
  def isInfoEnabled: Boolean
  def debug(...): Boolean
  def info(...): Boolean
}

class LoggerImpl {
  def debug(...) = {
  	// do whatever
  	false
  }
}

class ClientCode {
  val DBG = logger.isDebugEnabled // make it false/true if you like
  
  // instead of this:
  if(logger.isDebugEnabled) logger.debug(...)

  // do this:
  DBG && logger.debug(...)
}

IMO, the client should never test whether the debug mode is enabled in order to print a debug message. A method call is quite cheap in the JVM, so why polute the code with statements like

DBG && logger.debug(...)

when you can perform the test in the debug method?

Well, if I'd have to write those isDebugEnabled() calls, I'd prefer the Booleans instead. :)

Also, let's have in mind all those string concatenations or varargs array creation that may happen in order to finally do the actual call (depending on the logging framework, the developer etc).

Why not use call by name?
def debug(msg: => String) = if (isDebugEnabled) doActualLogging(msg)

Then the price for calling debug is the creation of a function object and the call itself

@ittayd Yes I am aware of the the by-name approach. The initial motivation was an attempt to get rid of IMO ugly if().