github.com/matrixorigin/matrixone@v1.2.0/pkg/sql/parsers/tree/accept.go (about)

     1  // Copyright 2021 Matrix Origin
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //      http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package tree
    16  
    17  //// Visitor Design Pattern
    18  //// Visitor visits the node or sub nodes
    19  //type Visitor interface {
    20  //	Enter(Expr) (bool, Expr)
    21  //	Exit(Expr) Expr
    22  //}