github.com/matrixorigin/matrixone@v1.2.0/pkg/sql/parsers/tree/datum.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  var (
    18  	constDBoolTrue  DBool = true
    19  	constDBoolFalse DBool = false
    20  
    21  	DBoolTrue  = &constDBoolTrue
    22  	DBoolFalse = &constDBoolFalse
    23  
    24  	DNull Datum = &dNull{}
    25  )
    26  
    27  type Datum interface {
    28  	Expr
    29  }
    30  
    31  type DBool bool
    32  
    33  func (node *DBool) Format(ctx *FmtCtx) {
    34  	ctx.WriteString(node.String())
    35  }
    36  
    37  func (node *DBool) String() string {
    38  	if *node {
    39  		return "true"
    40  	} else {
    41  		return "false"
    42  	}
    43  }
    44  
    45  func MakeDBool(d bool) *DBool {
    46  	if d {
    47  		return DBoolTrue
    48  	}
    49  	return DBoolFalse
    50  }
    51  
    52  type dNull struct {
    53  	Datum
    54  }
    55  
    56  func (node *dNull) Format(ctx *FmtCtx) {
    57  	ctx.WriteString("null")
    58  }