content: /*
   * Copyright 2021-2022 Alibaba Group Holding Ltd.
   *
   *    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.
   */
  
  package com.aliyun.fastmodel.parser.visitor;
  
  import com.aliyun.fastmodel.core.tree.Node;
  import com.aliyun.fastmodel.core.tree.expr.BaseExpression;
  import com.aliyun.fastmodel.core.tree.expr.Identifier;
  import com.aliyun.fastmodel.core.tree.expr.literal.StringLiteral;
  import com.aliyun.fastmodel.core.tree.statement.impexp.ExportStatement;
  import com.aliyun.fastmodel.parser.AstBuilder;
  import com.aliyun.fastmodel.parser.annotation.SubVisitor;
  import com.aliyun.fastmodel.parser.generate.FastModelGrammarParser.ExportBusinessUnitContext;
  import com.aliyun.fastmodel.parser.generate.FastModelGrammarParser.ExportStatementContext;
  
  /**
   * ExportVisitor
   *
   * @author panguanjing
   * @date 2021/8/22
   */
  @SubVisitor
  public class ImpExpVisitor extends AstBuilder {
      @Override
      public Node visitExportStatement(ExportStatementContext ctx) {
          StringLiteral output = null;
          if (ctx.exportOutput() != null) {
              output = (StringLiteral)visit(ctx.exportOutput().string());
          }
          Identifier identifier = null;
          ExportBusinessUnitContext exportBusinessUnitContext = ctx.exportBusinessUnit();
          if (exportBusinessUnitContext != null) {
              identifier = (Identifier)visit(exportBusinessUnitContext.identifier());
          }
          StringLiteral target = null;
          if (ctx.exportTarget() != null) {
              target = (StringLiteral)visit(ctx.exportTarget().string());
          }
          return new ExportStatement(identifier,
              output,
              target,
              (BaseExpression)visit(ctx.expression())
          );
      }
  }
  