reflect.PtrValue.SetSub() to set pointers

R=rsc
OCL=19101
CL=19101

src/lib/reflect/test.go

@@ -91,6 +91,17 @@ func main() {
 	var s string;
 	var t reflect.Type;
 
+{
+	var ip *int32;
+	var i int32 = 1234;
+	vip := reflect.NewValue(&ip);
+	vi := reflect.NewValue(i);
+	vip.(reflect.PtrValue).Sub().(reflect.PtrValue).SetSub(vi);
+	if *ip != 1234 {
+		panicln("SetSub failure", *ip);
+	}
+}
+
 	// Types
 	typedump("missing", "$missing$");
 	typedump("int", "int");

src/lib/reflect/value.go

@@ -39,6 +39,7 @@ export type Empty interface {}	// TODO(r): Delete when no longer needed?
 export type Value interface {
 	Kind()	int;
 	Type()	Type;
+	Addr()	Addr;
 	Interface()	Empty;
 }
 
@@ -58,6 +59,10 @@ func (c *Common) Type() Type {
 	return c.typ
 }
 
+func (c *Common) Addr() Addr {
+	return c.addr
+}
+
 func (c *Common) Interface() Empty {
 	return sys.unreflect(*AddrToPtrAddr(c.addr), c.typ.String());
 }
@@ -493,6 +498,7 @@ export type PtrValue interface {
 	Type()	Type;
 	Sub()	Value;
 	Get()	Addr;
+	SetSub(Value);
 }
 
 type PtrValueStruct struct {
@@ -507,6 +513,10 @@ func (v *PtrValueStruct) Sub() Value {
 	return NewValueAddr(v.typ.(PtrType).Sub(), v.Get());
 }
 
+func (v *PtrValueStruct) SetSub(subv Value)  {
+	*AddrToPtrAddr(v.addr) = subv.Addr();
+}
+
 func PtrCreator(typ Type, addr Addr) Value {
 	return &PtrValueStruct{ Common{PtrKind, typ, addr} };
 }