text: # coding=utf-8
  # Copyright 2018-2020 EVA
  #
  # 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.
  
  from eva.parser.evaql.evaql_parserVisitor import evaql_parserVisitor
  from eva.parser.evaql.evaql_parser import evaql_parser
  from eva.parser.types import ParserOrderBySortType
  from eva.expression.constant_value_expression import ConstantValueExpression
  
  
  ##################################################################
  # SELECT STATEMENT
  ##################################################################
  class Select(evaql_parserVisitor):
      def visitSimpleSelect(self, ctx: evaql_parser.SimpleSelectContext):
          select_stmt = self.visitChildren(ctx)
          return select_stmt
  
      def visitOrderByClause(self, ctx: evaql_parser.OrderByClauseContext):
          orderby_clause_data = []
          # [(TupleValueExpression #1, ASC), (TVE #2, DESC), ...]
          for expression in ctx.orderByExpression():
              orderby_clause_data.append(self.visit(expression))
  
          return orderby_clause_data
  
      def visitOrderByExpression(
              self, ctx: evaql_parser.OrderByExpressionContext):
  
          if ctx.DESC():
              sort_token = ParserOrderBySortType.DESC
          else:
              sort_token = ParserOrderBySortType.ASC
  
          return self.visitChildren(ctx.expression()), sort_token
  
      def visitLimitClause(self, ctx: evaql_parser.LimitClauseContext):
          return ConstantValueExpression(self.visitChildren(ctx))
  