cue: make use of Go 1.20+ APIs

Now that we require Go 1.20 or later, we can use reflect.Value.SetZero
and bytes.Clone, which are clearer and faster.

Signed-off-by: Daniel Martí <[email protected]>
Change-Id: I6bee04ec9e42aaaa4d15e1bc8e1aa90d64b4134b
Reviewed-on: https://review.gerrithub.io/c/cue-lang/cue/+/1167629
TryBot-Result: CUEcueckoo <[email protected]>
Unity-Result: CUE porcuepine <[email protected]>
Reviewed-by: Roger Peppe <[email protected]>

Author: mvdan

cue/decode.go

@@ -70,7 +70,7 @@ func incompleteError(v Value) errors.Error {
 
 func (d *decoder) clear(x reflect.Value) {
 	if x.CanSet() {
-		x.Set(reflect.Zero(x.Type()))
+		x.SetZero()
 	}
 }
 
@@ -373,11 +373,10 @@ func (d *decoder) convertMap(x reflect.Value, v Value) {
 			}
 		}
 
-		elemType := t.Elem()
 		if !mapElem.IsValid() {
-			mapElem = reflect.New(elemType).Elem()
+			mapElem = reflect.New(t.Elem()).Elem()
 		} else {
-			mapElem.Set(reflect.Zero(elemType))
+			mapElem.SetZero()
 		}
 		d.decode(mapElem, iter.Value(), false)
 

cue/types.go

@@ -1332,7 +1332,7 @@ func (v Value) Bytes() ([]byte, error) {
 	ctx := v.ctx()
 	switch x := v.eval(ctx).(type) {
 	case *adt.Bytes:
-		return append([]byte(nil), x.B...), nil
+		return bytes.Clone(x.B), nil
 	case *adt.String:
 		return []byte(x.Str), nil
 	}