add All method for iteration using range over func

README.md

@@ -47,10 +47,24 @@ func main() {
 	e2 := linq.Where(e1, func(s Student) (bool, error) { return s.Class == "1-B", nil })
 	e3 := linq.OrderByDescending(e2, func(s Student) (int, error) { return s.Score, nil })
 
-	linq.ForEach(e3, func(s Student) error {
+	// go1.23.0 or later
+	for s, err := range e3.All() {
+		if err != nil {
+			panic(err)
+		}
+		fmt.Printf("%d %s\n", s.Score, s.Name)
+	}
+
+	fmt.Println("----")
+
+	// it also works in older go
+	err := linq.ForEach(e3, func(s Student) error {
 		fmt.Printf("%d %s\n", s.Score, s.Name)
 		return nil
 	})
+	if err != nil {
+		panic(err)
+	}
 }
 ```
 
@@ -60,6 +74,11 @@ Output:
 425 山路 信之
 405 緒方 俊
 136 星 雅彦
+----
+594 三宅 直人
+425 山路 信之
+405 緒方 俊
+136 星 雅彦
 ```
 
 ## Functions

iter.go

@@ -0,0 +1,34 @@
+//go:build go1.23
+
+package linq
+
+import "iter"
+
+func (e Enumerable[T]) All() iter.Seq2[T, error] {
+	return iterAll(e())
+}
+
+func (e OrderedEnumerable[T]) All() iter.Seq2[T, error] {
+	return iterAll(e())
+}
+
+func iterAll[T any, E Enumerator[T]](e E) iter.Seq2[T, error] {
+	return func(yield func(T, error) bool) {
+		for {
+			v, err := e.Next()
+			if err != nil {
+				if isEOC(err) {
+					return
+				}
+			}
+
+			if !yield(v, err) {
+				return
+			}
+
+			if err != nil {
+				return
+			}
+		}
+	}
+}

iter_test.go

@@ -0,0 +1,25 @@
+//go:build go1.23
+
+package linq_test
+
+import (
+	"testing"
+
+	"github.com/makiuchi-d/linq/v2"
+)
+
+func TestIterAll(t *testing.T) {
+	src := linq.FromSlice([]int{1, 2, 3, 4, 5})
+	c := 0
+	s := 0
+	for n, err := range src.All() {
+		if err != nil {
+			t.Fatalf("%v", err)
+		}
+		c++
+		s += n
+	}
+	if c != 5 || s != 15 {
+		t.Fatalf("(c, s) = (%v, %v) wants (%v, %v)", c, s, 5, 15)
+	}
+}