github.com/XiaoMi/Gaea@v1.2.5/parser/types/eval_type.go (about)

     1  // Copyright 2017 PingCAP, Inc.
     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  // See the License for the specific language governing permissions and
    12  // limitations under the License.
    13  
    14  package types
    15  
    16  // EvalType indicates the specified types that arguments and result of a built-in function should be.
    17  type EvalType byte
    18  
    19  const (
    20  	// ETInt represents type INT in evaluation.
    21  	ETInt EvalType = iota
    22  	// ETReal represents type REAL in evaluation.
    23  	ETReal
    24  	// ETDecimal represents type DECIMAL in evaluation.
    25  	ETDecimal
    26  	// ETString represents type STRING in evaluation.
    27  	ETString
    28  	// ETDatetime represents type DATETIME in evaluation.
    29  	ETDatetime
    30  	// ETTimestamp represents type TIMESTAMP in evaluation.
    31  	ETTimestamp
    32  	// ETDuration represents type DURATION in evaluation.
    33  	ETDuration
    34  	// ETJson represents type JSON in evaluation.
    35  	ETJson
    36  )
    37  
    38  // IsStringKind returns true for ETString, ETDatetime, ETTimestamp, ETDuration, ETJson EvalTypes.
    39  func (et EvalType) IsStringKind() bool {
    40  	return et == ETString || et == ETDatetime ||
    41  		et == ETTimestamp || et == ETDuration || et == ETJson
    42  }