refactor(coperator): 将 Filter 类型从 map 修改为接口

- 将 Filter 类型从 map[string]interface{} 修改为 interface{}
- 在 DocumentOperator 和 FieldOperator 函数中添加 filter 类型检查
- 修改函数参数名称以适应新的 Filter 类型
- 优化错误处理，当 filter 类型不正确时返回错误

coperator.go

@@ -72,14 +72,17 @@ func (d *Document) GetPathArray(path []string) interface{} {
 }
 
 type Collection []Document
-type Filter map[string]interface{}
+type Filter interface{}
 
 type Operator func(doc *Document, filter Filter, key string, value interface{}) (bool, error)
 
 var operatorMap = map[string]Operator{}
 
-func DocumentOperator(doc *Document, filter Filter, key string, value interface{}) (ret bool, err error) {
+func DocumentOperator(doc *Document, vfilter Filter, key string, value interface{}) (ret bool, err error) {
-
+	filter, ok := vfilter.(map[string]interface{})
+	if !ok {
+		return false, errors.New("filter must be a map")
+	}
 	for k, v := range filter {
 
 		if strings.HasPrefix(k, "$") {
@@ -117,7 +120,11 @@ func ValueOperator(doc *Document, filter Filter, key string, value interface{})
 	return true, nil
 }
 
-func FieldOperator(doc *Document, filter Filter, key string, value interface{}) (ret bool, err error) {
+func FieldOperator(doc *Document, vfilter Filter, key string, value interface{}) (ret bool, err error) {
+	filter, ok := vfilter.(map[string]interface{})
+	if !ok {
+		return false, errors.New("filter must be a map")
+	}
 	for k, v := range filter {
 		if !strings.HasPrefix(k, "$") {
 			return false, errors.New("uncorrect grammar")