[#4465] Add new FieldOrRow type to provide a common super-type for Field<?> and Row

jOOQ/src/main/java/org/jooq/Field.java

@@ -79,7 +79,7 @@ import org.jooq.types.Interval;
  * @param <T> The field type
  * @author Lukas Eder
  */
-public interface Field<T> extends SelectField<T>, GroupField {
+public interface Field<T> extends SelectField<T>, GroupField, FieldOrRow {
 
     // ------------------------------------------------------------------------
     // API

jOOQ/src/main/java/org/jooq/FieldOrRow.java

@@ -0,0 +1,61 @@
+/**
+ * Copyright (c) 2009-2015, Data Geekery GmbH (http://www.datageekery.com)
+ * All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+ * Other licenses:
+ * -----------------------------------------------------------------------------
+ * Commercial licenses for this work are available. These replace the above
+ * ASL 2.0 and offer limited warranties, support, maintenance, and commercial
+ * database integrations.
+ *
+ * For more information, please visit: http://www.jooq.org/licenses
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ *
+ */
+package org.jooq;
+
+/**
+ * A common base type for {@link Field} and {@link Row} where DSL API accepts
+ * both types alike.
+ * <p>
+ * This is useful for expressions like <code>GROUPING SETS</code>, when
+ * expressing things like
+ *
+ * <pre>
+ * <code>
+ * CUBE ( (a,b), (c,d) )
+ * ROLLUP ( a, (b,c), d )
+ * </code>
+ * </pre>
+ *
+ * @author Lukas Eder
+ */
+public interface FieldOrRow extends QueryPart {
+
+}

jOOQ/src/main/java/org/jooq/Row.java

@@ -50,7 +50,7 @@ package org.jooq;
  *
  * @author Lukas Eder
  */
-public interface Row extends QueryPart {
+public interface Row extends FieldOrRow {
 
     /**
      * Get the degree of this row value expression.