github.com/dolthub/dolt/go@v0.40.5-0.20240520175717-68db7794bea6/libraries/utils/structwalk/walk.go (about)

     1  // Copyright 2024 Dolthub, 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  // 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 structwalk
    16  
    17  import (
    18  	"reflect"
    19  )
    20  
    21  func Walk(v any, f func(sf reflect.StructField, depth int) error) error {
    22  	return walkStruct(v, 0, f)
    23  }
    24  
    25  func walkStruct(v any, depth int, f func(sf reflect.StructField, depth int) error) error {
    26  	t := reflect.TypeOf(v)
    27  	if t.Kind() == reflect.Ptr {
    28  		t = t.Elem()
    29  	}
    30  
    31  	return walkFields(t, depth, f)
    32  }
    33  
    34  func walkFields(t reflect.Type, depth int, f func(sf reflect.StructField, depth int) error) error {
    35  	for i := 0; i < t.NumField(); i++ {
    36  		field := t.Field(i)
    37  		err := processField(field, depth, f)
    38  		if err != nil {
    39  			return err
    40  		}
    41  	}
    42  
    43  	return nil
    44  }
    45  
    46  func processField(field reflect.StructField, depth int, f func(sf reflect.StructField, depth int) error) error {
    47  	if err := f(field, depth); err != nil {
    48  		return err
    49  	}
    50  
    51  	if field.Type.Kind() == reflect.Ptr || field.Type.Kind() == reflect.Slice {
    52  		if field.Type.Elem().Kind() == reflect.Struct {
    53  			t := field.Type.Elem()
    54  			if err := walkFields(t, depth+1, f); err != nil {
    55  				return err
    56  			}
    57  		}
    58  	} else if field.Type.Kind() == reflect.Struct {
    59  		if err := walkFields(field.Type, depth+1, f); err != nil {
    60  			return err
    61  		}
    62  	}
    63  
    64  	return nil
    65  }