content: /*
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to you 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.
   */
  package org.apache.calcite.sql.validate;
  
  import org.apache.calcite.rel.type.RelDataType;
  import org.apache.calcite.sql.SqlCall;
  import org.apache.calcite.sql.SqlCallBinding;
  import org.apache.calcite.sql.SqlNode;
  import org.apache.calcite.sql.SqlOperator;
  import org.apache.calcite.sql.SqlTableFunction;
  import org.apache.calcite.sql.type.SqlReturnTypeInference;
  import org.apache.calcite.sql.type.SqlTypeName;
  
  import org.checkerframework.checker.nullness.qual.Nullable;
  
  import static java.util.Objects.requireNonNull;
  
  /**
   * Namespace whose contents are defined by the result of a call to a
   * user-defined procedure.
   */
  public class ProcedureNamespace extends AbstractNamespace {
    //~ Instance fields --------------------------------------------------------
  
    private final SqlValidatorScope scope;
  
    private final SqlCall call;
  
    //~ Constructors -----------------------------------------------------------
  
    ProcedureNamespace(
        SqlValidatorImpl validator,
        SqlValidatorScope scope,
        SqlCall call,
        SqlNode enclosingNode) {
      super(validator, enclosingNode);
      this.scope = scope;
      this.call = call;
    }
  
    //~ Methods ----------------------------------------------------------------
  
    @Override public RelDataType validateImpl(RelDataType targetRowType) {
      validator.inferUnknownTypes(validator.unknownType, scope, call);
      final RelDataType type = validator.deriveTypeImpl(scope, call);
      final SqlOperator operator = call.getOperator();
      final SqlCallBinding callBinding =
          new SqlCallBinding(validator, scope, call);
      if (!(operator instanceof SqlTableFunction)) {
        throw new IllegalArgumentException("Argument must be a table function: "
            + operator.getNameAsId());
      }
      final SqlTableFunction tableFunction = (SqlTableFunction) operator;
      if (type.getSqlTypeName() != SqlTypeName.CURSOR) {
        throw new IllegalArgumentException("Table function should have CURSOR "
            + "type, not " + type);
      }
      final SqlReturnTypeInference rowTypeInference =
          tableFunction.getRowTypeInference();
      return requireNonNull(
          rowTypeInference.inferReturnType(callBinding),
          () -> "got null from inferReturnType for call " + callBinding.getCall());
    }
  
    @Override public @Nullable SqlNode getNode() {
      return call;
    }
  }
  