fusenapi/utils/collect/collect.go

package collect

import (
	"reflect"
	"strconv"
)

func ArrayColumn[R any, T any](arr []T, column string) []R {
	var result []R
	s := reflect.ValueOf(arr)

	for i := 0; i < s.Len(); i++ {
		e := s.Index(i)
		k := e.FieldByName(column)
		result = append(result, k.Interface().(R))
	}

	return result
}

func ArrayColumnTag[R any, T any](arrSrc []T, tag string) []R {
	var result []R
	arr := reflect.ValueOf(arrSrc)
	if arr.Len() == 0 {
		return result
	}

	eleType := arr.Index(0).Elem().Type()

	for j := 0; j < eleType.NumField(); j++ {
		if value, ok := eleType.Field(j).Tag.Lookup("json"); ok && value == tag {

			for i := 0; i < arr.Len(); i++ {
				srcv := arr.Index(i)
				fv := srcv.Elem().Field(j)
				result = append(result, fv.Interface().(R))
			}

			return result
		}
	}

	return result
}

func ArrayIndex[T any](arr []T, index int) (result T, ok bool) {
	if index < len(arr) {
		result = arr[index]
		ok = true
		return
	}
	ok = false
	return
}

func ArrayString2Int(arr interface{}) (result []int64) {
	for _, a := range arr.([]string) {
		v, err := strconv.ParseInt(a, 10, 64)
		if err != nil {
			panic(err)
		}
		result = append(result, v)
	}
	return result
}

func Array2MapByKey[KEY comparable, VALUE any](arrSrc []VALUE, fieldName string) (result map[KEY]VALUE) {
	result = make(map[KEY]VALUE)
	arr := reflect.ValueOf(arrSrc)

	for i := 0; i < arr.Len(); i++ {
		srcv := arr.Index(i)
		fv := srcv.Elem().FieldByName(fieldName)
		k := fv.Interface().(KEY)
		result[k] = srcv.Interface().(VALUE)
	}

	return result
}

func Array2MapByKeyTag[KEY comparable, VALUE any](arrSrc []VALUE, tag string) (result map[KEY]VALUE) {

	arr := reflect.ValueOf(arrSrc)

	if arr.Len() == 0 {
		return result
	}
	result = make(map[KEY]VALUE)

	eleType := arr.Index(0).Elem().Type()

	for j := 0; j < eleType.NumField(); j++ {
		if value, ok := eleType.Field(j).Tag.Lookup("json"); ok && value == tag {

			for i := 0; i < arr.Len(); i++ {
				srcv := arr.Index(i)
				fv := srcv.Elem().Field(j)
				k := fv.Interface().(KEY)
				result[k] = srcv.Interface().(VALUE)
			}

			return
		}
	}

	return result
}