added a couple of helper methods to Map to be able look up in a Map with function to provide a default value

stdlib/ktSrc/JavaUtil.kt

@@ -195,3 +195,39 @@ val <T> List<T>.tail : T?
 val <T> List<T>.last : T?
   get() = this.tail
 
+
+
+// Map APIs
+/** Returns the size of the map */
+/* TODO get redeclaration errors
+val Map<*,*>.size : Int
+    get() = size()
+*/
+
+/** Returns true if this map is empty */
+/* TODO get redeclaration errors
+val Map<*,*>.empty : Boolean
+    get() = isEmpty()
+*/
+
+/** Returns the value for the given key or returns the result of the defaultValue function if there was no entry for the given key */
+inline fun <K,V> java.util.Map<K,V>.getOrElse(key: K, defaultValue: fun(): V) : V {
+  val current = this.get(key)
+  if (current != null) {
+    return current
+  } else {
+    return defaultValue()
+  }
+}
+
+/** Returns the value for the given key or the result of the defaultValue function is put into the map for the given value and returned */
+inline fun <K,V> java.util.Map<K,V>.getOrElseUpdate(key: K, defaultValue: fun(): V) : V {
+  val current = this.get(key)
+  if (current != null) {
+    return current
+  } else {
+    val answer = defaultValue()
+    this.put(key, answer)
+    return answer
+  }
+}