dawidwys commented on a change in pull request #7967: [FLINK-11449][table]
Uncouple the Expression class from RexNodes
URL: https://github.com/apache/flink/pull/7967#discussion_r264742116
##########
File path:
flink-table/flink-table-planner/src/main/scala/org/apache/flink/table/validate/FunctionCatalog.scala
##########
@@ -63,252 +112,16 @@ class FunctionCatalog {
)
/**
- * Lookup and create an expression if we find a match.
+ * Lookup a function by name and operands and return the
[[FunctionDefinition]].
*/
- def lookupFunction(name: String, children: Seq[Expression]): Expression = {
- val funcClass = functionBuilders
- .getOrElse(name.toLowerCase, throw new ValidationException(s"Undefined
function: $name"))
-
- // Instantiate a function using the provided `children`
- funcClass match {
-
- // user-defined scalar function call
- case sf if classOf[ScalarFunction].isAssignableFrom(sf) =>
- val scalarSqlFunction = sqlFunctions
- .find(f => f.getName.equalsIgnoreCase(name) &&
f.isInstanceOf[ScalarSqlFunction])
- .getOrElse(throw new ValidationException(s"Undefined scalar
function: $name"))
- .asInstanceOf[ScalarSqlFunction]
- ScalarFunctionCall(scalarSqlFunction.getScalarFunction, children)
-
- // user-defined table function call
- case tf if classOf[TableFunction[_]].isAssignableFrom(tf) =>
- val tableSqlFunction = sqlFunctions
- .find(f => f.getName.equalsIgnoreCase(name) &&
f.isInstanceOf[TableSqlFunction])
- .getOrElse(throw new ValidationException(s"Undefined table function:
$name"))
- .asInstanceOf[TableSqlFunction]
- val typeInfo = tableSqlFunction.getRowTypeInfo
- val function = tableSqlFunction.getTableFunction
- TableFunctionCall(name, function, children, typeInfo)
-
- // user-defined aggregate function call
- case af if classOf[AggregateFunction[_, _]].isAssignableFrom(af) =>
- val aggregateFunction = sqlFunctions
- .find(f => f.getName.equalsIgnoreCase(name) &&
f.isInstanceOf[AggSqlFunction])
- .getOrElse(throw new ValidationException(s"Undefined table function:
$name"))
- .asInstanceOf[AggSqlFunction]
- val function = aggregateFunction.getFunction
- val returnType = aggregateFunction.returnType
- val accType = aggregateFunction.accType
- AggFunctionCall(function, returnType, accType, children)
-
- // general expression call
- case expression if classOf[Expression].isAssignableFrom(expression) =>
- // try to find a constructor accepts `Seq[Expression]`
- Try(funcClass.getDeclaredConstructor(classOf[Seq[_]])) match {
- case Success(seqCtor) =>
- Try(seqCtor.newInstance(children).asInstanceOf[Expression]) match {
- case Success(expr) => expr
- case Failure(e) => throw new ValidationException(e.getMessage)
- }
- case Failure(_) =>
- Try(funcClass.getDeclaredConstructor(classOf[Expression],
classOf[Seq[_]])) match {
- case Success(ctor) =>
- Try(ctor.newInstance(children.head,
children.tail).asInstanceOf[Expression]) match {
- case Success(expr) => expr
- case Failure(e) => throw new
ValidationException(e.getMessage)
- }
- case Failure(_) =>
- val childrenClass =
Seq.fill(children.length)(classOf[Expression])
- // try to find a constructor matching the exact number of
children
- Try(funcClass.getDeclaredConstructor(childrenClass: _*)) match
{
- case Success(ctor) =>
- Try(ctor.newInstance(children:
_*).asInstanceOf[Expression]) match {
- case Success(expr) => expr
- case Failure(exception) => throw new
ValidationException(exception.getMessage)
- }
- case Failure(_) =>
- throw new ValidationException(
- s"Invalid number of arguments for function $funcClass")
- }
- }
- }
- case _ =>
- throw new ValidationException("Unsupported function.")
- }
+ def lookupFunction(name: String, children: Seq[Expression]):
FunctionDefinition = {
Review comment:
I would remove the `children`. It is not used for the lookup and complicates
other places.
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