reflect: Value.Seq iteration value types should match

Implementation of golang/go#71905

194696f1d1f6e5609f96d0fb0192595e7e0f5b90

Author: ydnar

src/reflect/iter.go

@@ -6,15 +6,24 @@
 
 package reflect
 
-import "iter"
+import (
+	"iter"
+)
 
 func rangeNum[T int8 | int16 | int32 | int64 | int |
 	uint8 | uint16 | uint32 | uint64 | uint |
-	uintptr, N int64 | uint64](v N) iter.Seq[Value] {
+	uintptr, N int64 | uint64](num N, t Type) iter.Seq[Value] {
 	return func(yield func(v Value) bool) {
+		convert := t.PkgPath() != ""
 		// cannot use range T(v) because no core type.
-		for i := T(0); i < T(v); i++ {
-			if !yield(ValueOf(i)) {
+		for i := T(0); i < T(num); i++ {
+			tmp := ValueOf(i)
+			// if the iteration value type is define by
+			// type T built-in type.
+			if convert {
+				tmp = tmp.Convert(t)
+			}
+			if !yield(tmp) {
 				return
 			}
 		}
@@ -40,27 +49,27 @@ func (v Value) Seq() iter.Seq[Value] {
 	// }
 	switch v.Kind() {
 	case Int:
-		return rangeNum[int](v.Int())
+		return rangeNum[int](v.Int(), v.Type())
 	case Int8:
-		return rangeNum[int8](v.Int())
+		return rangeNum[int8](v.Int(), v.Type())
 	case Int16:
-		return rangeNum[int16](v.Int())
+		return rangeNum[int16](v.Int(), v.Type())
 	case Int32:
-		return rangeNum[int32](v.Int())
+		return rangeNum[int32](v.Int(), v.Type())
 	case Int64:
-		return rangeNum[int64](v.Int())
+		return rangeNum[int64](v.Int(), v.Type())
 	case Uint:
-		return rangeNum[uint](v.Uint())
+		return rangeNum[uint](v.Uint(), v.Type())
 	case Uint8:
-		return rangeNum[uint8](v.Uint())
+		return rangeNum[uint8](v.Uint(), v.Type())
 	case Uint16:
-		return rangeNum[uint16](v.Uint())
+		return rangeNum[uint16](v.Uint(), v.Type())
 	case Uint32:
-		return rangeNum[uint32](v.Uint())
+		return rangeNum[uint32](v.Uint(), v.Type())
 	case Uint64:
-		return rangeNum[uint64](v.Uint())
+		return rangeNum[uint64](v.Uint(), v.Type())
 	case Uintptr:
-		return rangeNum[uintptr](v.Uint())
+		return rangeNum[uintptr](v.Uint(), v.Type())
 	case Pointer:
 		if v.Elem().Kind() != Array {
 			break

src/reflect/iter_test.go

@@ -197,10 +197,11 @@ func TestValueSeq(t *testing.T) {
 					t.Fatalf("got %d, want %d", v.Int(), i)
 				}
 				i++
-				// TODO: iteration should produce the same type
-				// if v.Type() != reflect.TypeOf(i) {
-				// 	t.Fatalf("got %s, want %s", v.Type(), reflect.TypeOf(i))
-				// }
+				if v.Type() != reflect.TypeOf(i) {
+					j := ValueOf(i)
+					t.Logf("ValueOf(j): %s", j.Type())
+					t.Fatalf("got %s, want %s", v.Type(), reflect.TypeOf(i))
+				}
 			}
 			if i != 4 {
 				t.Fatalf("should loop four times")