github.com/vescale/zgraph@v0.0.0-20230410094002-959c02d50f95/parser/model/str.go (about)

     1  // Copyright 2022 zGraph Authors. All rights reserved.
     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 model
    16  
    17  import (
    18  	"encoding/json"
    19  	"strings"
    20  
    21  	"github.com/pingcap/errors"
    22  )
    23  
    24  // CIStr is case-insensitive string.
    25  type CIStr struct {
    26  	O string `json:"O"` // Original string.
    27  	L string `json:"L"` // Lower case string.
    28  }
    29  
    30  // String implements fmt.Stringer interface.
    31  func (cis CIStr) String() string {
    32  	return cis.O
    33  }
    34  
    35  // Equal reports whether `cis` is equal to `other` in a case-insensitive way.
    36  func (cis CIStr) Equal(other CIStr) bool {
    37  	return cis.L == other.L
    38  }
    39  
    40  // IsEmpty reports whether the CIStr is an empty string
    41  func (cis CIStr) IsEmpty() bool {
    42  	return cis.O == ""
    43  }
    44  
    45  // NewCIStr creates a new CIStr.
    46  func NewCIStr(s string) (cs CIStr) {
    47  	cs.O = s
    48  	cs.L = strings.ToLower(s)
    49  	return
    50  }
    51  
    52  // UnmarshalJSON implements the user defined unmarshal method.
    53  // CIStr can be unmarshaled from a single string, so PartitionDefinition.Name
    54  // in this change https://github.com/pingcap/tidb/pull/6460/files would be
    55  // compatible during TiDB upgrading.
    56  func (cis *CIStr) UnmarshalJSON(b []byte) error {
    57  	type T CIStr
    58  	if err := json.Unmarshal(b, (*T)(cis)); err == nil {
    59  		return nil
    60  	}
    61  
    62  	// Unmarshal CIStr from a single string.
    63  	err := json.Unmarshal(b, &cis.O)
    64  	if err != nil {
    65  		return errors.Trace(err)
    66  	}
    67  	cis.L = strings.ToLower(cis.O)
    68  	return nil
    69  }