From 51a55c742a9a349408b032423196d51a6eadff53 Mon Sep 17 00:00:00 2001
From: twalthr <twalthr@apache.org>
Date: Mon, 26 Jun 2017 09:28:59 +0200
Subject: [PATCH 1/2] [FLINK-6942] [table] Add E() support in Table API

---
 .../flink/table/api/scala/expressionDsl.scala       | 13 +++++++++++++
 .../flink/table/expressions/mathExpressions.scala   | 11 +++++++++++
 .../flink/table/validate/FunctionCatalog.scala      |  1 +
 .../table/expressions/ScalarFunctionsTest.scala     |  8 ++++++--
 4 files changed, 31 insertions(+), 2 deletions(-)

diff --git a/flink-libraries/flink-table/src/main/scala/org/apache/flink/table/api/scala/expressionDsl.scala b/flink-libraries/flink-table/src/main/scala/org/apache/flink/table/api/scala/expressionDsl.scala
index 0fb940f525b97..9370c572d09a9 100644
--- a/flink-libraries/flink-table/src/main/scala/org/apache/flink/table/api/scala/expressionDsl.scala
+++ b/flink-libraries/flink-table/src/main/scala/org/apache/flink/table/api/scala/expressionDsl.scala
@@ -923,6 +923,19 @@ object pi {
   }
 }
 
+/**
+  * Returns a value that is closer than any other value to e.
+  */
+object e {
+
+  /**
+    * Returns a value that is closer than any other value to e.
+    */
+  def apply(): Expression = {
+    E()
+  }
+}
+
 /**
   * Returns a pseudorandom double value between 0.0 (inclusive) and 1.0 (exclusive).
   */
diff --git a/flink-libraries/flink-table/src/main/scala/org/apache/flink/table/expressions/mathExpressions.scala b/flink-libraries/flink-table/src/main/scala/org/apache/flink/table/expressions/mathExpressions.scala
index f78d91706d568..3f8085b142e67 100644
--- a/flink-libraries/flink-table/src/main/scala/org/apache/flink/table/expressions/mathExpressions.scala
+++ b/flink-libraries/flink-table/src/main/scala/org/apache/flink/table/expressions/mathExpressions.scala
@@ -22,6 +22,7 @@ import org.apache.calcite.sql.fun.SqlStdOperatorTable
 import org.apache.calcite.tools.RelBuilder
 import org.apache.flink.api.common.typeinfo.BasicTypeInfo._
 import org.apache.flink.api.common.typeinfo.{BasicTypeInfo, TypeInformation}
+import org.apache.flink.table.functions.sql.ScalarSqlFunctions
 import org.apache.flink.table.typeutils.TypeCheckUtils
 import org.apache.flink.table.validate._
 
@@ -287,6 +288,16 @@ case class Pi() extends LeafExpression {
   }
 }
 
+case class E() extends LeafExpression {
+  override private[flink] def resultType: TypeInformation[_] = DOUBLE_TYPE_INFO
+
+  override def toString: String = s"e()"
+
+  override private[flink] def toRexNode(implicit relBuilder: RelBuilder): RexNode = {
+    relBuilder.call(ScalarSqlFunctions.E)
+  }
+}
+
 case class Rand(seed: Expression) extends Expression with InputTypeSpec {
 
   def this() = this(null)
diff --git a/flink-libraries/flink-table/src/main/scala/org/apache/flink/table/validate/FunctionCatalog.scala b/flink-libraries/flink-table/src/main/scala/org/apache/flink/table/validate/FunctionCatalog.scala
index 4bc636490869c..6d3006d9e28ca 100644
--- a/flink-libraries/flink-table/src/main/scala/org/apache/flink/table/validate/FunctionCatalog.scala
+++ b/flink-libraries/flink-table/src/main/scala/org/apache/flink/table/validate/FunctionCatalog.scala
@@ -223,6 +223,7 @@ object FunctionCatalog {
     "sign" -> classOf[Sign],
     "round" -> classOf[Round],
     "pi" -> classOf[Pi],
+    "e" -> classOf[E],
     "rand" -> classOf[Rand],
     "randInteger" -> classOf[RandInteger],
 
diff --git a/flink-libraries/flink-table/src/test/scala/org/apache/flink/table/expressions/ScalarFunctionsTest.scala b/flink-libraries/flink-table/src/test/scala/org/apache/flink/table/expressions/ScalarFunctionsTest.scala
index b684108a37af9..d4c2a450e93d0 100644
--- a/flink-libraries/flink-table/src/test/scala/org/apache/flink/table/expressions/ScalarFunctionsTest.scala
+++ b/flink-libraries/flink-table/src/test/scala/org/apache/flink/table/expressions/ScalarFunctionsTest.scala
@@ -1149,11 +1149,15 @@ class ScalarFunctionsTest extends ExpressionTestBase {
 
   @Test
   def testE(): Unit = {
-    testSqlApi(
+    testAllApis(
+      e(),
+      "E()",
       "E()",
       math.E.toString)
 
-    testSqlApi(
+    testAllApis(
+      e(),
+      "e()",
       "e()",
       math.E.toString)
   }

From 8f911f97ec4d05f5a77871533163df7da230df89 Mon Sep 17 00:00:00 2001
From: twalthr <twalthr@apache.org>
Date: Mon, 26 Jun 2017 10:36:02 +0200
Subject: [PATCH 2/2] Add docs

---
 docs/dev/table/tableApi.md | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/docs/dev/table/tableApi.md b/docs/dev/table/tableApi.md
index 34cee244fde30..02f34321ed7fb 100644
--- a/docs/dev/table/tableApi.md
+++ b/docs/dev/table/tableApi.md
@@ -2068,6 +2068,17 @@ pi()
       </td>
     </tr>
 
+    <tr>
+      <td>
+        {% highlight java %}
+e()
+{% endhighlight %}
+      </td>
+      <td>
+        <p>Returns a value that is closer than any other value to e.</p>
+      </td>
+    </tr>
+
     <tr>
       <td>
         {% highlight java %}
@@ -3320,6 +3331,17 @@ pi()
       </td>
     </tr>
 
+    <tr>
+      <td>
+        {% highlight scala %}
+e()
+{% endhighlight %}
+      </td>
+      <td>
+        <p>Returns a value that is closer than any other value to e.</p>
+      </td>
+    </tr>
+
     <tr>
       <td>
         {% highlight scala %}