some more documentation

src/main/java/at/datasciencelabs/EsperSelectFunction.java

@@ -10,5 +10,12 @@
  * @param <OUT> Type of the output DataStream
  */
 public interface EsperSelectFunction<OUT> extends Function, Serializable {
+
+    /**
+     * Select by transforming an {@link EventBean} to an instance of the OUT type.
+     * @param eventBean Result event of an esper pattern
+     * @return The transformed instance
+     * @throws Exception If there is an error in the transformation.
+     */
     OUT select(EventBean eventBean) throws Exception;
 }

src/main/java/at/datasciencelabs/EsperStream.java

@@ -37,7 +37,7 @@ public <R> SingleOutputStreamOperator<R> select(EsperSelectFunction<R> esperSele
 
         SingleOutputStreamOperator<R> patternStream;
 
-        // TODO until the typeextractor is capable of extracing non-generic parameters, the return type has to be passed in manually
+        // TODO until the type extractor is capable of extracting non-generic parameters, the return type has to be passed in manually
 
         final boolean isProcessingTime = inputStream.getExecutionEnvironment().getStreamTimeCharacteristic() == TimeCharacteristic.ProcessingTime;
         patternStream = inputStream.keyBy(keySelector).transform("SelectEsperOperator", dataStreamReturnType, new SelectEsperStreamOperator<Byte, IN, R>(inputStream.getType(), esperSelectFunction, isProcessingTime, esperQuery));

src/main/java/at/datasciencelabs/SelectEsperStreamOperator.java

@@ -30,10 +30,10 @@ public class SelectEsperStreamOperator<KEY, IN, OUT> extends AbstractUdfStreamOp
     /**
      * Constructs a new operator. Requires the type of the input DataStream to register its Event Type at Esper.
      * Currently only processing time evaluation is supported.
-     * @param inputStreamType
-     * @param esperSelectFunction
-     * @param isProcessingTime
-     * @param esperQuery
+     * @param inputStreamType type of the input DataStream
+     * @param esperSelectFunction function to select from Esper's output
+     * @param isProcessingTime Flag indicating how time is interpreted (processing time vs event time)
+     * @param esperQuery The esper query
      */
     public SelectEsperStreamOperator(TypeInformation<IN> inputStreamType, EsperSelectFunction<OUT> esperSelectFunction, boolean isProcessingTime, String esperQuery) {
         super(esperSelectFunction);