started work on bug 86, http://bugzilla.slf4j.org/show_bug.cgi?id=86

slf4j-ext/src/main/java/org/slf4j/LoggerX.java

@@ -0,0 +1,61 @@
+package org.slf4j;
+
+import org.slf4j.helpers.MessageFormatter;
+import org.slf4j.spi.LocationAwareLogger;
+
+/**
+ * A utility that provides standard mechanisms for logging certain kinds of
+ * activities.
+ * 
+ * @author Ralph Goers
+ * @author Ceki Gulcu
+ */
+public class LoggerX {
+
+  private static final String FQCN = LoggerX.class.getName();
+  static Marker FLOW_MARKER = MarkerFactory.getMarker("FLOW");
+  static Marker ENTRY_MARKER = MarkerFactory.getMarker("ENTER");
+  static Marker EXIT_MARKER = MarkerFactory.getMarker("EXIT");
+
+  static Marker EXCEPTION_MARKER = MarkerFactory.getMarker("EXCEPTION");
+  static Marker DIAG_MARKER = MarkerFactory.getMarker("DIAG");
+
+  static String ENTRY_MESSAGE_0 = "entry";
+  static String ENTRY_MESSAGE_1 = "entry with params ({})";
+  static String ENTRY_MESSAGE_2 = "entry with params ({}, {})";
+  static String ENTRY_MESSAGE_3 = "entry with params ({}, {}, {})";
+  static String ENTRY_MESSAGE_4 = "entry with params ({}, {}, {}, {})";
+  static int ENTRY_MESSAGE_ARRAY_LEN = 5;
+  static String[] ENTRY_MESSAGE_ARRAY = new String[ENTRY_MESSAGE_ARRAY_LEN];
+  static {
+    ENTRY_MARKER.add(FLOW_MARKER);
+    EXIT_MARKER.add(FLOW_MARKER);
+    ENTRY_MESSAGE_ARRAY[0] = ENTRY_MESSAGE_0;
+    ENTRY_MESSAGE_ARRAY[1] = ENTRY_MESSAGE_1;
+    ENTRY_MESSAGE_ARRAY[2] = ENTRY_MESSAGE_2;
+    ENTRY_MESSAGE_ARRAY[3] = ENTRY_MESSAGE_3;
+    ENTRY_MESSAGE_ARRAY[4] = ENTRY_MESSAGE_4;
+  }
+
+  /**
+   * Log entry to a method
+   * 
+   * @param logger
+   *                the Logger to log with.
+   */
+  public static void entering(Logger logger, Object... argArray) {
+    if (logger.isDebugEnabled(ENTRY_MARKER)
+        && logger instanceof LocationAwareLogger) {
+      String messagePattern = "";
+      if(argArray.length <= ENTRY_MESSAGE_ARRAY_LEN) {
+        messagePattern = ENTRY_MESSAGE_ARRAY[argArray.length];
+      }
+      
+      String msg = MessageFormatter.arrayFormat(messagePattern, argArray);
+      
+      ((LocationAwareLogger) logger).log(ENTRY_MARKER, FQCN,
+          LocationAwareLogger.ERROR_INT, msg, null);
+    }
+  }
+
+}

slf4j-ext/src/test/java/org/slf4j/LoggerXTest.java

@@ -0,0 +1,12 @@
+package org.slf4j;
+
+import junit.framework.TestCase;
+
+public class LoggerXTest extends TestCase {
+
+  Logger logger = LoggerFactory.getLogger(this.getClass());
+  
+  public void testSmoke() {
+    LoggerX.entering(logger);
+  }
+}