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;
  
  import org.apache.calcite.sql.parser.SqlParserPos;
  import org.apache.calcite.sql.parser.SqlParserUtil;
  import org.apache.calcite.sql.type.SqlTypeName;
  import org.apache.calcite.util.NlsString;
  import org.apache.calcite.util.Util;
  
  import static java.util.Objects.requireNonNull;
  
  /**
   * Literal whose type is not yet known.
   */
  public class SqlUnknownLiteral extends SqlLiteral {
    public final String tag;
  
    SqlUnknownLiteral(String tag, String value, SqlParserPos pos) {
      super(requireNonNull(value, "value"), SqlTypeName.UNKNOWN, pos);
      this.tag = requireNonNull(tag, "tag");
    }
  
    @Override public String getValue() {
      return (String) requireNonNull(super.getValue(), "value");
    }
  
    @Override public SqlLiteral clone(SqlParserPos pos) {
      return new SqlUnknownLiteral(tag, getValue(), pos);
    }
  
    @Override public void unparse(SqlWriter writer, int leftPrec, int rightPrec) {
      final NlsString nlsString = new NlsString(getValue(), null, null);
      writer.keyword(tag);
      writer.literal(nlsString.asSql(true, true, writer.getDialect()));
    }
  
  
    /** Converts this unknown literal to a literal of known type. */
    public SqlLiteral resolve(SqlTypeName typeName) {
      switch (typeName) {
      case DATE:
        return SqlParserUtil.parseDateLiteral(getValue(), pos);
      case TIME:
        return SqlParserUtil.parseTimeLiteral(getValue(), pos);
      case TIME_TZ:
        return SqlParserUtil.parseTimeTzLiteral(getValue(), pos);
      case TIMESTAMP:
        return SqlParserUtil.parseTimestampLiteral(getValue(), pos);
      case TIMESTAMP_WITH_LOCAL_TIME_ZONE:
        return SqlParserUtil.parseTimestampWithLocalTimeZoneLiteral(getValue(), pos);
      case TIMESTAMP_TZ:
        return SqlParserUtil.parseTimestampTzLiteral(getValue(), pos);
      case UUID:
        return SqlParserUtil.parseUuidLiteral(getValue(), pos);
      default:
        throw Util.unexpected(typeName);
      }
    }
  }
  