crazy_fox_backend_api/utils/map.go

package utils

import (
	"reflect"
	"sort"
	"strconv"

	"golang.org/x/exp/constraints"
)

// MapValues 获取Map中所有的Key,作为切片返回,可排序
func MapValues[K constraints.Ordered, V any](m map[K]V, order bool) []V {
	values := make([]V, 0, len(m))

	if !order {
		for _, v := range m {
			values = append(values, v)
		}
	} else {
		keys := MapKeys(m, true)
		for i := 0; i < len(keys); i++ {
			values = append(values, m[keys[i]])
		}
	}

	return values
}

// MapKeys 获取Map中所有的Value,作为切片返回,可排序
func MapKeys[K constraints.Ordered, V any](m map[K]V, order bool) []K {
	keys := make([]K, 0, len(m))
	for k := range m {
		keys = append(keys, k)
	}

	if order {
		sort.SliceStable(keys, func(i, j int) bool {
			return keys[i] < keys[j]
		})
	}
	return keys
}

// Slice2Map 切片转化为map,map的key从1开始累加
func Slice2Map[T any](s []T) map[int64]T {
	m := make(map[int64]T, len(s))

	for i, v := range s {
		m[int64(i+1)] = v
	}

	return m
}

// ArrayColumns 参照php ArrayColumns
func ArrayColumns[T any](input []T, column string) map[string]T {
	var output = make(map[string]T, len(input))
	var key string
	if len(input) < 1 {
		return output
	}
	immutableT := reflect.TypeOf(input[0])
	field, ok := immutableT.FieldByName(column)
	if !ok {
		return output
	}

	for _, row := range input {
		switch field.Type.Kind() {
		case reflect.String:
			key = reflect.ValueOf(row).FieldByName(column).Interface().(string)
		case reflect.Int64:
			tk := reflect.ValueOf(row).FieldByName(column).Interface().(int64)
			key = strconv.Itoa(int(tk))
		case reflect.Int:
			tk := reflect.ValueOf(row).FieldByName(column).Interface().(int)
			key = strconv.Itoa(tk)

		}
		output[key] = row
	}

	return output
}