Added a logging version of Kestrel combinator

build.sbt

@@ -13,6 +13,7 @@ crossScalaVersions := Seq(
     "2.9.0-1",
     "2.9.1")
 
+
 libraryDependencies ++= Seq(
     "org.slf4j" % "slf4j-api" % "1.6.1")
 

src/main/scala/Logging.scala

@@ -23,5 +23,5 @@ trait Logging {
   /**
    * Logger for the type mixed into.
    */
-  protected[slf4s] lazy val logger = Logger(this.getClass)
+  protected[slf4s] implicit lazy val logger = Logger(this.getClass)
 }

src/main/scala/LoggingUtilities.scala

@@ -0,0 +1,45 @@
+package com.weiglewilczek.slf4s
+
+/*
+ * A mixin with logging utilities.
+ */
+trait LoggingUtilities {
+  implicit def wrapAny[A](value: A) = new AnyWrapper(value)
+
+  class AnyWrapper[A](value: A) {
+
+    /**
+     * This is a logging version of Kestrel combinator.
+     *
+     * This method is very similar to Object#tap method in Ruby. It prints the given message along with the object
+     * on which the method was invoked, and evaluates to the same object. It is used to tap into method chains, in
+     * in order to inspect the values of object at various stages in processing.
+     *
+     * Example:
+     *   List.range(1, 10).trace("Original")
+     *       .map(2 *).trace("After mapping")
+     *       .filter(4 <).trace("After filtering")
+     *       .size.trace("Size")
+     *
+     * The default logging method invoked is Logger#debug. It is easy to invoke other logging methods instead, if
+     * so required.
+     *
+     * Example:
+     *   List.range(1, 10).trace("Original", _.info)
+     *
+     * @param message The message to be logged along with the object value.
+     * @param logFn The logging method to use. By default, set to Logger#debug.
+     * @param logger The logger to use for logging.
+     * @return The object on which the method was invoked.
+     */
+    def trace(message: => String, logFn: Logger => (=> String) => Unit = _.debug)(implicit logger: Logger): A = {
+      logFn(logger)(message + ": " + value)
+      value
+    }
+  }
+}
+
+/*
+ * A first class module that provides logging utilities.
+ */
+object LoggingUtilities extends LoggingUtilities