Add ForEach

example_test.go

@@ -55,7 +55,7 @@ func ExampleSet_1setfield() {
 	Set(&p, "Gender", 1)
 	printJsonV(p)
 	fmt.Println(MustGet(&p, "Score"))
-	//Output:
+	// Output:
 	// {
 	// 	"Name": "Felix",
 	// 	"Score": 66.88,
@@ -77,7 +77,7 @@ func ExampleSet_2setstructproperty() {
 	printJsonV(p)
 	fmt.Println(MustGet(&p, ".Company.Phone.Number"))
 
-	//Output:
+	// Output:
 	// {
 	// 	"Name": "",
 	// 	"Score": 0,
@@ -112,7 +112,7 @@ func ExampleSet_3setsliceproperty() {
 	fmt.Println(MustGet(&p, "Departments[4].Name"))
 	fmt.Println(MustGet(&p, "Projects[0].Name"))
 
-	//Output:
+	// Output:
 	// {
 	// 	"Name": "",
 	// 	"Score": 0,
@@ -156,7 +156,7 @@ func ExampleSet_4setmapproperty() {
 	printJsonV(p)
 	fmt.Println(MustGet(&p, "Languages.zh_CN.Code"))
 
-	//Output:
+	// Output:
 	// {
 	// 	"Name": "",
 	// 	"Score": 0,
@@ -186,7 +186,7 @@ func ExampleSet_5setdeeper() {
 
 	printJsonV(p)
 	fmt.Println(MustGet(&p, "Projects[0].Members[0].Company.Phone.Number"))
-	//Output:
+	// Output:
 	// {
 	// 	"Name": "",
 	// 	"Score": 0,
@@ -232,7 +232,7 @@ func ExampleSet_6appendtoarray() {
 		Set(&p, "Departments[]", d)
 	}
 	printJsonV(p)
-	//Output:
+	// Output:
 	// {
 	// 	"Name": "",
 	// 	"Score": 0,
@@ -287,12 +287,12 @@ func ExampleSet_6byteandstring() {
 	fmt.Println(o.IntValue)
 	fmt.Println(o.FloatValue)
 	fmt.Println(o.IntValueForBytes)
-	//Output:
-	//hello
-	//Felix
-	//22
-	//22.88
-	//22
+	// Output:
+	// hello
+	// Felix
+	// 22
+	// 22.88
+	// 22
 
 }
 
@@ -302,19 +302,18 @@ func ExampleSet_7notexists() {
 	err := Set(&p, "Whatever.Not.Exists", "911")
 
 	fmt.Println(err)
-	//Output:
+	// Output:
 	// no such field
 }
 
-
 // Get Type of a deep nested object
 func ExampleSet_8gettype() {
 	type Variant struct {
 		Name string
 	}
 	type Product struct {
 		Variants []*Variant
-		ByCode map[string]*Variant
+		ByCode   map[string]*Variant
 	}
 	type Obj struct {
 		MainProduct *Product
@@ -330,15 +329,76 @@ func ExampleSet_8gettype() {
 	fmt.Println(GetType(o, "MainProduct.ByCode"))
 	fmt.Println(GetType(o, "x123.ByCode"))
 	fmt.Println(GetType(o, "MainProduct.ByCode.abc.NotExist"))
-	//Output:
-	//string
-	//*reflectutils_test.Variant
-	//[]*reflectutils_test.Variant
-	//*reflectutils_test.Product
-	//*reflectutils_test.Variant
-	//map[string]*reflectutils_test.Variant
-	//<nil>
-	//<nil>
+	// Output:
+	// string
+	// *reflectutils_test.Variant
+	// []*reflectutils_test.Variant
+	// *reflectutils_test.Product
+	// *reflectutils_test.Variant
+	// map[string]*reflectutils_test.Variant
+	// <nil>
+	// <nil>
+}
+
+// ForEach slice with any
+func ExampleForEach_9_0_normal() {
+	var arr = []*Language{
+		{"en_US", "United States"},
+		{"zh_CN", "China"},
+	}
+
+	ForEach(arr, func(v any) {
+		ve := v.(*Language)
+		fmt.Printf("%s\n", ve.Name)
+	})
+	// Output:
+	// United States
+	// China
+}
+
+// ForEach slice with correct type
+func ExampleForEach_9_1_with_type() {
+	var arr = []*Language{
+		{"en_US", "United States"},
+		{"zh_CN", "China"},
+	}
+
+	ForEach(arr, func(v *Language) {
+		fmt.Printf("%s\n", v.Name)
+	})
+	// Output:
+	// United States
+	// China
+}
+
+// ForEach map with any
+func ExampleForEach_9_2_map_with_any() {
+	var m = map[string]*Language{
+		"en_US": {"en_US", "United States"},
+		"zh_CN": {"zh_CN", "China"},
+	}
+
+	ForEach(m, func(c any, v any) {
+		fmt.Printf("%s: %s\n", c.(string), v.(*Language).Name)
+	})
+	// Output:
+	// en_US: United States
+	// zh_CN: China
+}
+
+// ForEach map with any
+func ExampleForEach_9_3_map_with_correct_type() {
+	var m = map[string]*Language{
+		"en_US": {"en_US", "United States"},
+		"zh_CN": {"zh_CN", "China"},
+	}
+
+	ForEach(m, func(c string, v *Language) {
+		fmt.Printf("%s: %s\n", c, v.Name)
+	})
+	// Output:
+	// en_US: United States
+	// zh_CN: China
 }
 
 func printJsonV(v interface{}) {

foreach.go

@@ -0,0 +1,82 @@
+package reflectutils
+
+import (
+	"fmt"
+	"reflect"
+)
+
+func ForEach(arr interface{}, predicate interface{}) {
+	var (
+		funcValue = reflect.ValueOf(predicate)
+		arrValue  = reflect.ValueOf(arr)
+		arrType   = arrValue.Type()
+		arrKind   = arrType.Kind()
+		funcType  = funcValue.Type()
+	)
+
+	if IsNil(arr) {
+		return
+	}
+
+	if !(arrKind == reflect.Array || arrKind == reflect.Slice || arrKind == reflect.Map) {
+		panic("First parameter must be an iteratee")
+	}
+
+	if arrKind == reflect.Slice || arrKind == reflect.Array {
+		if !isFunction(predicate, 1, 0) {
+			panic("Second argument must be a function with one parameter")
+		}
+
+		arrElemType := arrValue.Type().Elem()
+
+		// Checking whether element type is convertible to function's first argument's type.
+		if !arrElemType.ConvertibleTo(funcType.In(0)) {
+			panic("Map function's argument is not compatible with type of array.")
+		}
+
+		for i := 0; i < arrValue.Len(); i++ {
+			funcValue.Call([]reflect.Value{arrValue.Index(i)})
+		}
+		return
+	}
+
+	if arrKind == reflect.Map {
+		if !isFunction(predicate, 2, 0) {
+			panic("Second argument must be a function with two parameters")
+		}
+
+		// Type checking for Map<key, value> = (key, value)
+		keyType := arrType.Key()
+		valueType := arrType.Elem()
+
+		if !keyType.ConvertibleTo(funcType.In(0)) {
+			panic(fmt.Sprintf("function first argument is not compatible with %s", keyType.String()))
+		}
+
+		if !valueType.ConvertibleTo(funcType.In(1)) {
+			panic(fmt.Sprintf("function second argument is not compatible with %s", valueType.String()))
+		}
+
+		for _, key := range arrValue.MapKeys() {
+			funcValue.Call([]reflect.Value{key, arrValue.MapIndex(key)})
+		}
+		return
+	}
+}
+
+// isFunction returns if the argument is a function.
+func isFunction(in interface{}, num ...int) bool {
+	funcType := reflect.TypeOf(in)
+
+	result := funcType != nil && funcType.Kind() == reflect.Func
+
+	if len(num) >= 1 {
+		result = result && funcType.NumIn() == num[0]
+	}
+
+	if len(num) == 2 {
+		result = result && funcType.NumOut() == num[1]
+	}
+
+	return result
+}

go.mod

@@ -1,3 +1,3 @@
 module github.com/sunfmin/reflectutils
 
-go 1.17
+go 1.22