diff --git a/internal/builtins/abs.go b/internal/builtins/abs.go
index 586155c..fc0ab7f 100644
--- a/internal/builtins/abs.go
+++ b/internal/builtins/abs.go
@@ -15,10 +15,10 @@ func Abs(args ...object.Object) object.Object {
 		return newError(err.Error())
 	}
 
-	i := args[0].(*object.Integer)
+	i := args[0].(object.Integer)
 	value := i.Value
 	if value < 0 {
 		value = value * -1
 	}
-	return &object.Integer{Value: value}
+	return object.Integer{Value: value}
 }
diff --git a/internal/builtins/accept.go b/internal/builtins/accept.go
index 9ee1c43..ea9f906 100644
--- a/internal/builtins/accept.go
+++ b/internal/builtins/accept.go
@@ -21,12 +21,12 @@ func Accept(args ...object.Object) object.Object {
 		err error
 	)
 
-	fd := int(args[0].(*object.Integer).Value)
+	fd := int(args[0].(object.Integer).Value)
 
 	nfd, _, err = syscall.Accept(fd)
 	if err != nil {
 		return newError("SocketError: %s", err)
 	}
 
-	return &object.Integer{Value: int64(nfd)}
+	return object.Integer{Value: int64(nfd)}
 }
diff --git a/internal/builtins/args.go b/internal/builtins/args.go
index c91b28e..65d6c4a 100644
--- a/internal/builtins/args.go
+++ b/internal/builtins/args.go
@@ -16,7 +16,7 @@ func args(args ...object.Object) object.Object {
 
 	elements := make([]object.Object, len(object.Args))
 	for i, arg := range object.Args {
-		elements[i] = &object.String{Value: arg}
+		elements[i] = object.String{Value: arg}
 	}
 	return &object.Array{Elements: elements}
 }
diff --git a/internal/builtins/assert.go b/internal/builtins/assert.go
index 6d69d9a..b11b7fa 100644
--- a/internal/builtins/assert.go
+++ b/internal/builtins/assert.go
@@ -17,8 +17,8 @@ func Assert(args ...object.Object) object.Object {
 		return newError(err.Error())
 	}
 
-	if !args[0].(*object.Boolean).Value {
-		fmt.Printf("Assertion Error: %s", args[1].(*object.String).Value)
+	if !args[0].(object.Boolean).Value {
+		fmt.Printf("Assertion Error: %s", args[1].(object.String).Value)
 		os.Exit(1)
 	}
 
diff --git a/internal/builtins/bin.go b/internal/builtins/bin.go
index 1b6795e..1357773 100644
--- a/internal/builtins/bin.go
+++ b/internal/builtins/bin.go
@@ -17,6 +17,6 @@ func Bin(args ...object.Object) object.Object {
 		return newError(err.Error())
 	}
 
-	i := args[0].(*object.Integer)
-	return &object.String{Value: fmt.Sprintf("0b%s", strconv.FormatInt(i.Value, 2))}
+	i := args[0].(object.Integer)
+	return object.String{Value: fmt.Sprintf("0b%s", strconv.FormatInt(i.Value, 2))}
 }
diff --git a/internal/builtins/bind.go b/internal/builtins/bind.go
index 4365ad4..90483c5 100644
--- a/internal/builtins/bind.go
+++ b/internal/builtins/bind.go
@@ -21,8 +21,8 @@ func Bind(args ...object.Object) object.Object {
 		sockaddr syscall.Sockaddr
 	)
 
-	fd := int(args[0].(*object.Integer).Value)
-	address := args[1].(*object.String).Value
+	fd := int(args[0].(object.Integer).Value)
+	address := args[1].(object.String).Value
 
 	sockaddr, err = syscall.Getsockname(fd)
 	if err != nil {
@@ -50,5 +50,5 @@ func Bind(args ...object.Object) object.Object {
 		return newError("SocketError: %s", err)
 	}
 
-	return &object.Null{}
+	return object.Null{}
 }
diff --git a/internal/builtins/bool.go b/internal/builtins/bool.go
index 0c361d9..13f8136 100644
--- a/internal/builtins/bool.go
+++ b/internal/builtins/bool.go
@@ -14,5 +14,5 @@ func Bool(args ...object.Object) object.Object {
 		return newError(err.Error())
 	}
 
-	return &object.Boolean{Value: args[0].Bool()}
+	return object.Boolean{Value: args[0].Bool()}
 }
diff --git a/internal/builtins/builtins.go b/internal/builtins/builtins.go
index b46a891..26e5d27 100644
--- a/internal/builtins/builtins.go
+++ b/internal/builtins/builtins.go
@@ -72,6 +72,6 @@ func init() {
 	}
 }
 
-func newError(format string, a ...interface{}) *object.Error {
-	return &object.Error{Message: fmt.Sprintf(format, a...)}
+func newError(format string, a ...interface{}) object.Error {
+	return object.Error{Message: fmt.Sprintf(format, a...)}
 }
diff --git a/internal/builtins/chr.go b/internal/builtins/chr.go
index 9df165c..f8cbb69 100644
--- a/internal/builtins/chr.go
+++ b/internal/builtins/chr.go
@@ -16,6 +16,6 @@ func Chr(args ...object.Object) object.Object {
 		return newError(err.Error())
 	}
 
-	i := args[0].(*object.Integer)
-	return &object.String{Value: fmt.Sprintf("%c", rune(i.Value))}
+	i := args[0].(object.Integer)
+	return object.String{Value: fmt.Sprintf("%c", rune(i.Value))}
 }
diff --git a/internal/builtins/close.go b/internal/builtins/close.go
index 1cc63bb..6f72b44 100644
--- a/internal/builtins/close.go
+++ b/internal/builtins/close.go
@@ -16,12 +16,12 @@ func Close(args ...object.Object) object.Object {
 		return newError(err.Error())
 	}
 
-	fd := int(args[0].(*object.Integer).Value)
+	fd := int(args[0].(object.Integer).Value)
 
 	err := syscall.Close(fd)
 	if err != nil {
 		return newError("IOError: %s", err)
 	}
 
-	return &object.Null{}
+	return object.Null{}
 }
diff --git a/internal/builtins/connect.go b/internal/builtins/connect.go
index 38161b1..c5e2eee 100644
--- a/internal/builtins/connect.go
+++ b/internal/builtins/connect.go
@@ -18,8 +18,8 @@ func Connect(args ...object.Object) object.Object {
 
 	var sa syscall.Sockaddr
 
-	fd := int(args[0].(*object.Integer).Value)
-	address := args[1].(*object.String).Value
+	fd := int(args[0].(object.Integer).Value)
+	address := args[1].(object.String).Value
 
 	sockaddr, err := syscall.Getsockname(fd)
 	if err != nil {
@@ -46,5 +46,5 @@ func Connect(args ...object.Object) object.Object {
 		return newError("SocketError: %s", err)
 	}
 
-	return &object.Null{}
+	return object.Null{}
 }
diff --git a/internal/builtins/divmod.go b/internal/builtins/divmod.go
index a23ecbf..cd21a24 100644
--- a/internal/builtins/divmod.go
+++ b/internal/builtins/divmod.go
@@ -15,10 +15,10 @@ func Divmod(args ...object.Object) object.Object {
 		return newError(err.Error())
 	}
 
-	a := args[0].(*object.Integer)
-	b := args[1].(*object.Integer)
+	a := args[0].(object.Integer)
+	b := args[1].(object.Integer)
 	elements := make([]object.Object, 2)
-	elements[0] = &object.Integer{Value: a.Value / b.Value}
-	elements[1] = &object.Integer{Value: a.Value % b.Value}
+	elements[0] = object.Integer{Value: a.Value / b.Value}
+	elements[1] = object.Integer{Value: a.Value % b.Value}
 	return &object.Array{Elements: elements}
 }
diff --git a/internal/builtins/exit.go b/internal/builtins/exit.go
index 3f7b9d1..f440507 100644
--- a/internal/builtins/exit.go
+++ b/internal/builtins/exit.go
@@ -17,7 +17,7 @@ func Exit(args ...object.Object) object.Object {
 
 	var status int
 	if len(args) == 1 {
-		status = int(args[0].(*object.Integer).Value)
+		status = int(args[0].(object.Integer).Value)
 	}
 
 	object.ExitFunction(status)
diff --git a/internal/builtins/ffi.go b/internal/builtins/ffi.go
index a43c8bc..d18a552 100644
--- a/internal/builtins/ffi.go
+++ b/internal/builtins/ffi.go
@@ -20,8 +20,8 @@ func FFI(args ...object.Object) object.Object {
 		return newError(err.Error())
 	}
 
-	name := args[0].(*object.String).Value
-	symbol := args[1].(*object.String).Value
+	name := args[0].(object.String).Value
+	symbol := args[1].(object.String).Value
 
 	p, err := plugin.Open(fmt.Sprintf("%s.so", name))
 	if err != nil {
diff --git a/internal/builtins/find.go b/internal/builtins/find.go
index 99a3a1b..49057b7 100644
--- a/internal/builtins/find.go
+++ b/internal/builtins/find.go
@@ -20,7 +20,7 @@ func Find(args ...object.Object) object.Object {
 	}
 
 	// find substring in string
-	if haystack, ok := args[0].(*object.String); ok {
+	if haystack, ok := args[0].(object.String); ok {
 		if err := typing.Check(
 			"find", args,
 			typing.WithTypes(object.StringType, object.StringType),
@@ -28,9 +28,9 @@ func Find(args ...object.Object) object.Object {
 			return newError(err.Error())
 		}
 
-		needle := args[1].(*object.String)
+		needle := args[1].(object.String)
 		index := strings.Index(haystack.Value, needle.Value)
-		return &object.Integer{Value: int64(index)}
+		return object.Integer{Value: int64(index)}
 	}
 
 	// find in array
@@ -40,9 +40,9 @@ func Find(args ...object.Object) object.Object {
 			return needle.Compare(haystack.Elements[i]) == 0
 		})
 		if i < len(haystack.Elements) && needle.Compare(haystack.Elements[i]) == 0 {
-			return &object.Integer{Value: int64(i)}
+			return object.Integer{Value: int64(i)}
 		}
-		return &object.Integer{Value: -1}
+		return object.Integer{Value: -1}
 	}
 
 	return newError(
diff --git a/internal/builtins/hash.go b/internal/builtins/hash.go
index 85cf451..072be42 100644
--- a/internal/builtins/hash.go
+++ b/internal/builtins/hash.go
@@ -15,7 +15,7 @@ func HashOf(args ...object.Object) object.Object {
 	}
 
 	if hash, ok := args[0].(object.Hashable); ok {
-		return &object.Integer{Value: int64(hash.HashKey().Value)}
+		return object.Integer{Value: int64(hash.HashKey().Value)}
 	}
 
 	return newError("TypeError: hash() expected argument #1 to be hashable")
diff --git a/internal/builtins/hex.go b/internal/builtins/hex.go
index a2d48a2..7c1c3e6 100644
--- a/internal/builtins/hex.go
+++ b/internal/builtins/hex.go
@@ -17,6 +17,6 @@ func Hex(args ...object.Object) object.Object {
 		return newError(err.Error())
 	}
 
-	i := args[0].(*object.Integer)
-	return &object.String{Value: fmt.Sprintf("0x%s", strconv.FormatInt(i.Value, 16))}
+	i := args[0].(object.Integer)
+	return object.String{Value: fmt.Sprintf("0x%s", strconv.FormatInt(i.Value, 16))}
 }
diff --git a/internal/builtins/id.go b/internal/builtins/id.go
index ab41d0b..5df86e8 100644
--- a/internal/builtins/id.go
+++ b/internal/builtins/id.go
@@ -17,25 +17,24 @@ func IdOf(args ...object.Object) object.Object {
 
 	arg := args[0]
 
-	if n, ok := arg.(*object.Null); ok {
-		return &object.String{Value: fmt.Sprintf("%p", n)}
-	} else if b, ok := arg.(*object.Boolean); ok {
-		return &object.String{Value: fmt.Sprintf("%p", b)}
-	} else if i, ok := arg.(*object.Integer); ok {
-		return &object.String{Value: fmt.Sprintf("%p", i)}
-	} else if s, ok := arg.(*object.String); ok {
-		return &object.String{Value: fmt.Sprintf("%p", s)}
+	if n, ok := arg.(object.Null); ok {
+		return object.String{Value: fmt.Sprintf("%p", &n)}
+	} else if b, ok := arg.(object.Boolean); ok {
+		return object.String{Value: fmt.Sprintf("%p", &b)}
+	} else if i, ok := arg.(object.Integer); ok {
+		return object.String{Value: fmt.Sprintf("%p", &i)}
+	} else if s, ok := arg.(object.String); ok {
+		return object.String{Value: fmt.Sprintf("%p", &s)}
 	} else if a, ok := arg.(*object.Array); ok {
-		return &object.String{Value: fmt.Sprintf("%p", a)}
+		return object.String{Value: fmt.Sprintf("%p", a)}
 	} else if h, ok := arg.(*object.Hash); ok {
-		return &object.String{Value: fmt.Sprintf("%p", h)}
+		return object.String{Value: fmt.Sprintf("%p", h)}
 	} else if f, ok := arg.(*object.Function); ok {
-		return &object.String{Value: fmt.Sprintf("%p", f)}
+		return object.String{Value: fmt.Sprintf("%p", f)}
 	} else if c, ok := arg.(*object.Closure); ok {
-		return &object.String{Value: fmt.Sprintf("%p", c)}
+		return object.String{Value: fmt.Sprintf("%p", c)}
 	} else if b, ok := arg.(*object.Builtin); ok {
-		return &object.String{Value: fmt.Sprintf("%p", b)}
+		return object.String{Value: fmt.Sprintf("%p", b)}
 	}
-
 	return nil
 }
diff --git a/internal/builtins/input.go b/internal/builtins/input.go
index b8b8c58..82ff13b 100644
--- a/internal/builtins/input.go
+++ b/internal/builtins/input.go
@@ -20,7 +20,7 @@ func Input(args ...object.Object) object.Object {
 	}
 
 	if len(args) == 1 {
-		prompt := args[0].(*object.String).Value
+		prompt := args[0].(object.String).Value
 		fmt.Fprintf(os.Stdout, prompt)
 	}
 
@@ -30,5 +30,5 @@ func Input(args ...object.Object) object.Object {
 	if err != nil && err != io.EOF {
 		return newError(fmt.Sprintf("error reading input from stdin: %s", err))
 	}
-	return &object.String{Value: string(line)}
+	return object.String{Value: string(line)}
 }
diff --git a/internal/builtins/int.go b/internal/builtins/int.go
index b77be9a..a9179cc 100644
--- a/internal/builtins/int.go
+++ b/internal/builtins/int.go
@@ -16,20 +16,20 @@ func Int(args ...object.Object) object.Object {
 	}
 
 	switch arg := args[0].(type) {
-	case *object.Boolean:
+	case object.Boolean:
 		if arg.Value {
-			return &object.Integer{Value: 1}
+			return object.Integer{Value: 1}
 		}
-		return &object.Integer{Value: 0}
-	case *object.Integer:
+		return object.Integer{Value: 0}
+	case object.Integer:
 		return arg
-	case *object.String:
+	case object.String:
 		n, err := strconv.ParseInt(arg.Value, 10, 64)
 		if err != nil {
 			return newError("could not parse string to int: %s", err)
 		}
-		return &object.Integer{Value: n}
+		return object.Integer{Value: n}
 	default:
-		return &object.Integer{}
+		return object.Integer{}
 	}
 }
diff --git a/internal/builtins/join.go b/internal/builtins/join.go
index d7f698b..eabf90d 100644
--- a/internal/builtins/join.go
+++ b/internal/builtins/join.go
@@ -17,10 +17,10 @@ func Join(args ...object.Object) object.Object {
 	}
 
 	arr := args[0].(*object.Array)
-	sep := args[1].(*object.String)
+	sep := args[1].(object.String)
 	a := make([]string, len(arr.Elements))
 	for i, el := range arr.Elements {
 		a[i] = el.String()
 	}
-	return &object.String{Value: strings.Join(a, sep.Value)}
+	return object.String{Value: strings.Join(a, sep.Value)}
 }
diff --git a/internal/builtins/len.go b/internal/builtins/len.go
index a73fd15..65fd41a 100644
--- a/internal/builtins/len.go
+++ b/internal/builtins/len.go
@@ -15,7 +15,7 @@ func Len(args ...object.Object) object.Object {
 	}
 
 	if size, ok := args[0].(object.Sizeable); ok {
-		return &object.Integer{Value: int64(size.Len())}
+		return object.Integer{Value: int64(size.Len())}
 	}
 	return newError("TypeError: object of type '%s' has no len()", args[0].Type())
 }
diff --git a/internal/builtins/listen.go b/internal/builtins/listen.go
index 6430380..a322dad 100644
--- a/internal/builtins/listen.go
+++ b/internal/builtins/listen.go
@@ -16,12 +16,12 @@ func Listen(args ...object.Object) object.Object {
 		return newError(err.Error())
 	}
 
-	fd := int(args[0].(*object.Integer).Value)
-	backlog := int(args[1].(*object.Integer).Value)
+	fd := int(args[0].(object.Integer).Value)
+	backlog := int(args[1].(object.Integer).Value)
 
 	if err := syscall.Listen(fd, backlog); err != nil {
 		return newError("SocketError: %s", err)
 	}
 
-	return &object.Null{}
+	return object.Null{}
 }
diff --git a/internal/builtins/lower.go b/internal/builtins/lower.go
index 808910c..9362b8a 100644
--- a/internal/builtins/lower.go
+++ b/internal/builtins/lower.go
@@ -16,6 +16,6 @@ func Lower(args ...object.Object) object.Object {
 		return newError(err.Error())
 	}
 
-	str := args[0].(*object.String)
-	return &object.String{Value: strings.ToLower(str.Value)}
+	str := args[0].(object.String)
+	return object.String{Value: strings.ToLower(str.Value)}
 }
diff --git a/internal/builtins/max.go b/internal/builtins/max.go
index 6c3f3e3..0dac2f0 100644
--- a/internal/builtins/max.go
+++ b/internal/builtins/max.go
@@ -20,12 +20,12 @@ func Max(args ...object.Object) object.Object {
 	// TODO: Make this more generic
 	xs := []int{} //make([]int, len(a.Elements))
 	for n, e := range a.Elements {
-		if i, ok := e.(*object.Integer); ok {
+		if i, ok := e.(object.Integer); ok {
 			xs = append(xs, int(i.Value))
 		} else {
 			return newError("item #%d  not an `int` got=%d", n, e.Type())
 		}
 	}
 	sort.Ints(xs)
-	return &object.Integer{Value: int64(xs[len(xs)-1])}
+	return object.Integer{Value: int64(xs[len(xs)-1])}
 }
diff --git a/internal/builtins/min.go b/internal/builtins/min.go
index ceeb999..4f4a279 100644
--- a/internal/builtins/min.go
+++ b/internal/builtins/min.go
@@ -20,12 +20,12 @@ func Min(args ...object.Object) object.Object {
 	// TODO: Make this more generic
 	xs := []int{} //make([]int, len(a.Elements))
 	for n, e := range a.Elements {
-		if i, ok := e.(*object.Integer); ok {
+		if i, ok := e.(object.Integer); ok {
 			xs = append(xs, int(i.Value))
 		} else {
 			return newError("item #%d  not an `int` got=%d", n, e.Type())
 		}
 	}
 	sort.Ints(xs)
-	return &object.Integer{Value: int64(xs[0])}
+	return object.Integer{Value: int64(xs[0])}
 }
diff --git a/internal/builtins/oct.go b/internal/builtins/oct.go
index 4cd5151..2e82f74 100644
--- a/internal/builtins/oct.go
+++ b/internal/builtins/oct.go
@@ -17,6 +17,6 @@ func Oct(args ...object.Object) object.Object {
 		return newError(err.Error())
 	}
 
-	i := args[0].(*object.Integer)
-	return &object.String{Value: fmt.Sprintf("0%s", strconv.FormatInt(i.Value, 8))}
+	i := args[0].(object.Integer)
+	return object.String{Value: fmt.Sprintf("0%s", strconv.FormatInt(i.Value, 8))}
 }
diff --git a/internal/builtins/open.go b/internal/builtins/open.go
index c240b5e..933bd3b 100644
--- a/internal/builtins/open.go
+++ b/internal/builtins/open.go
@@ -66,10 +66,10 @@ func Open(args ...object.Object) object.Object {
 		perm     uint32 = 0640
 	)
 
-	filename = args[0].(*object.String).Value
+	filename = args[0].(object.String).Value
 
 	if len(args) == 2 {
-		mode = args[1].(*object.String).Value
+		mode = args[1].(object.String).Value
 	}
 
 	flag, err := parseMode(mode)
@@ -82,5 +82,5 @@ func Open(args ...object.Object) object.Object {
 		return newError("IOError: %s", err)
 	}
 
-	return &object.Integer{Value: int64(fd)}
+	return object.Integer{Value: int64(fd)}
 }
diff --git a/internal/builtins/ord.go b/internal/builtins/ord.go
index 151e22d..1497523 100644
--- a/internal/builtins/ord.go
+++ b/internal/builtins/ord.go
@@ -15,9 +15,9 @@ func Ord(args ...object.Object) object.Object {
 		return newError(err.Error())
 	}
 
-	s := args[0].(*object.String)
+	s := args[0].(object.String)
 	if len(s.Value) == 1 {
-		return &object.Integer{Value: int64(s.Value[0])}
+		return object.Integer{Value: int64(s.Value[0])}
 	}
 	return newError(
 		"TypeError: ord() expected a single character `str` got=%s",
diff --git a/internal/builtins/pow.go b/internal/builtins/pow.go
index a6d8a85..cf7d859 100644
--- a/internal/builtins/pow.go
+++ b/internal/builtins/pow.go
@@ -27,8 +27,8 @@ func Pow(args ...object.Object) object.Object {
 		return newError(err.Error())
 	}
 
-	x := args[0].(*object.Integer)
-	y := args[1].(*object.Integer)
+	x := args[0].(object.Integer)
+	y := args[1].(object.Integer)
 	value := pow(x.Value, y.Value)
-	return &object.Integer{Value: value}
+	return object.Integer{Value: value}
 }
diff --git a/internal/builtins/read.go b/internal/builtins/read.go
index c119379..d11ec16 100644
--- a/internal/builtins/read.go
+++ b/internal/builtins/read.go
@@ -24,10 +24,10 @@ func Read(args ...object.Object) object.Object {
 		n  = DefaultBufferSize
 	)
 
-	fd = int(args[0].(*object.Integer).Value)
+	fd = int(args[0].(object.Integer).Value)
 
 	if len(args) == 2 {
-		n = int(args[1].(*object.Integer).Value)
+		n = int(args[1].(object.Integer).Value)
 	}
 
 	buf := make([]byte, n)
@@ -36,5 +36,5 @@ func Read(args ...object.Object) object.Object {
 		return newError("IOError: %s", err)
 	}
 
-	return &object.String{Value: string(buf[:n])}
+	return object.String{Value: string(buf[:n])}
 }
diff --git a/internal/builtins/readfile.go b/internal/builtins/readfile.go
index 988a106..c127de1 100644
--- a/internal/builtins/readfile.go
+++ b/internal/builtins/readfile.go
@@ -16,11 +16,11 @@ func ReadFile(args ...object.Object) object.Object {
 		return newError(err.Error())
 	}
 
-	filename := args[0].(*object.String).Value
+	filename := args[0].(object.String).Value
 	data, err := os.ReadFile(filename)
 	if err != nil {
 		return newError("IOError: error reading from file %s: %s", filename, err)
 	}
 
-	return &object.String{Value: string(data)}
+	return object.String{Value: string(data)}
 }
diff --git a/internal/builtins/seek.go b/internal/builtins/seek.go
index 761a7e9..8fd27a3 100644
--- a/internal/builtins/seek.go
+++ b/internal/builtins/seek.go
@@ -21,11 +21,11 @@ func Seek(args ...object.Object) object.Object {
 		whence = 0
 	)
 
-	fd = int(args[0].(*object.Integer).Value)
-	offset := args[1].(*object.Integer).Value
+	fd = int(args[0].(object.Integer).Value)
+	offset := args[1].(object.Integer).Value
 
 	if len(args) == 3 {
-		whence = int(args[2].(*object.Integer).Value)
+		whence = int(args[2].(object.Integer).Value)
 	}
 
 	offset, err := syscall.Seek(fd, offset, whence)
@@ -33,5 +33,5 @@ func Seek(args ...object.Object) object.Object {
 		return newError("IOError: %s", err)
 	}
 
-	return &object.Integer{Value: offset}
+	return object.Integer{Value: offset}
 }
diff --git a/internal/builtins/socket.go b/internal/builtins/socket.go
index 85f9242..fb21399 100644
--- a/internal/builtins/socket.go
+++ b/internal/builtins/socket.go
@@ -23,7 +23,7 @@ func Socket(args ...object.Object) object.Object {
 		proto  int
 	)
 
-	arg := args[0].(*object.String).Value
+	arg := args[0].(object.String).Value
 
 	switch strings.ToLower(arg) {
 	case "unix":
@@ -61,5 +61,5 @@ func Socket(args ...object.Object) object.Object {
 		}
 	}
 
-	return &object.Integer{Value: int64(fd)}
+	return object.Integer{Value: int64(fd)}
 }
diff --git a/internal/builtins/split.go b/internal/builtins/split.go
index f98973f..989fab7 100644
--- a/internal/builtins/split.go
+++ b/internal/builtins/split.go
@@ -17,16 +17,16 @@ func Split(args ...object.Object) object.Object {
 	}
 
 	var sep string
-	s := args[0].(*object.String).Value
+	s := args[0].(object.String).Value
 
 	if len(args) == 2 {
-		sep = args[1].(*object.String).Value
+		sep = args[1].(object.String).Value
 	}
 
 	tokens := strings.Split(s, sep)
 	elements := make([]object.Object, len(tokens))
 	for i, token := range tokens {
-		elements[i] = &object.String{Value: token}
+		elements[i] = object.String{Value: token}
 	}
 	return &object.Array{Elements: elements}
 }
diff --git a/internal/builtins/str.go b/internal/builtins/str.go
index 01e74dd..b45447c 100644
--- a/internal/builtins/str.go
+++ b/internal/builtins/str.go
@@ -14,5 +14,5 @@ func Str(args ...object.Object) object.Object {
 		return newError(err.Error())
 	}
 
-	return &object.String{Value: args[0].String()}
+	return object.String{Value: args[0].String()}
 }
diff --git a/internal/builtins/typeof.go b/internal/builtins/typeof.go
index be7c7c6..95b5ef1 100644
--- a/internal/builtins/typeof.go
+++ b/internal/builtins/typeof.go
@@ -14,5 +14,5 @@ func TypeOf(args ...object.Object) object.Object {
 		return newError(err.Error())
 	}
 
-	return &object.String{Value: args[0].Type().String()}
+	return object.String{Value: args[0].Type().String()}
 }
diff --git a/internal/builtins/upper.go b/internal/builtins/upper.go
index 5e82a54..c8702ea 100644
--- a/internal/builtins/upper.go
+++ b/internal/builtins/upper.go
@@ -16,5 +16,5 @@ func Upper(args ...object.Object) object.Object {
 		return newError(err.Error())
 	}
 
-	return &object.String{Value: strings.ToUpper(args[0].(*object.String).Value)}
+	return object.String{Value: strings.ToUpper(args[0].(object.String).Value)}
 }
diff --git a/internal/builtins/write.go b/internal/builtins/write.go
index c5bbe50..6b801f4 100644
--- a/internal/builtins/write.go
+++ b/internal/builtins/write.go
@@ -16,13 +16,13 @@ func Write(args ...object.Object) object.Object {
 		return newError(err.Error())
 	}
 
-	fd := int(args[0].(*object.Integer).Value)
-	data := []byte(args[1].(*object.String).Value)
+	fd := int(args[0].(object.Integer).Value)
+	data := []byte(args[1].(object.String).Value)
 
 	n, err := syscall.Write(fd, data)
 	if err != nil {
 		return newError("IOError: %s", err)
 	}
 
-	return &object.Integer{Value: int64(n)}
+	return object.Integer{Value: int64(n)}
 }
diff --git a/internal/builtins/writefile.go b/internal/builtins/writefile.go
index a185687..8fd385b 100644
--- a/internal/builtins/writefile.go
+++ b/internal/builtins/writefile.go
@@ -16,13 +16,13 @@ func WriteFile(args ...object.Object) object.Object {
 		return newError(err.Error())
 	}
 
-	filename := args[0].(*object.String).Value
-	data := []byte(args[1].(*object.String).Value)
+	filename := args[0].(object.String).Value
+	data := []byte(args[1].(object.String).Value)
 
 	err := os.WriteFile(filename, data, 0755)
 	if err != nil {
 		return newError("IOError: error writing file %s: %s", filename, err)
 	}
 
-	return &object.Null{}
+	return object.Null{}
 }
diff --git a/internal/compiler/bytecode.go b/internal/compiler/bytecode.go
index 19c336a..1123dbb 100644
--- a/internal/compiler/bytecode.go
+++ b/internal/compiler/bytecode.go
@@ -70,13 +70,13 @@ func (e *encoder) WriteObjects(objs ...object.Object) (err error) {
 		err = errors.Join(err, e.WriteValue(obj.Type()))
 
 		switch o := obj.(type) {
-		case *object.Null:
+		case object.Null:
 			break
-		case *object.Boolean:
+		case object.Boolean:
 			err = errors.Join(err, e.WriteValue(o.Value))
-		case *object.Integer:
+		case object.Integer:
 			err = errors.Join(err, e.WriteValue(o.Value))
-		case *object.String:
+		case object.String:
 			err = errors.Join(err, e.WriteValue(len(o.Value)))
 			err = errors.Join(err, e.WriteValue(o.Value))
 		case *object.CompiledFunction:
@@ -146,13 +146,13 @@ func (d *decoder) Objects(len int) (o []object.Object) {
 	for i := 0; i < len; i++ {
 		switch t := object.Type(d.Int()); t {
 		case object.NullType:
-			o = append(o, &object.Null{})
+			o = append(o, object.Null{})
 		case object.BooleanType:
-			o = append(o, &object.Boolean{Value: d.Byte() == 1})
+			o = append(o, object.Boolean{Value: d.Byte() == 1})
 		case object.IntegerType:
-			o = append(o, &object.Integer{Value: d.Int64()})
+			o = append(o, object.Integer{Value: d.Int64()})
 		case object.StringType:
-			o = append(o, &object.String{Value: d.String(d.Int())})
+			o = append(o, object.String{Value: d.String(d.Int())})
 		case object.CFunctionType:
 			// The order of the fields has to reflect the data layout in the encoded bytecode.
 			o = append(o, &object.CompiledFunction{
diff --git a/internal/compiler/compiler.go b/internal/compiler/compiler.go
index 17a2cdb..776641c 100644
--- a/internal/compiler/compiler.go
+++ b/internal/compiler/compiler.go
@@ -173,7 +173,7 @@ func (c *Compiler) Compile(node ast.Node) error {
 		}
 
 	case *ast.IntegerLiteral:
-		integer := &object.Integer{Value: node.Value}
+		integer := object.Integer{Value: node.Value}
 		c.emit(code.OpConstant, c.addConstant(integer))
 
 	case *ast.Null:
@@ -356,7 +356,7 @@ func (c *Compiler) Compile(node ast.Node) error {
 		c.loadSymbol(symbol)
 
 	case *ast.StringLiteral:
-		str := &object.String{Value: node.Value}
+		str := object.String{Value: node.Value}
 		c.emit(code.OpConstant, c.addConstant(str))
 
 	case *ast.ArrayLiteral:
diff --git a/internal/compiler/compiler_test.go b/internal/compiler/compiler_test.go
index 9dc4356..c4a48a3 100644
--- a/internal/compiler/compiler_test.go
+++ b/internal/compiler/compiler_test.go
@@ -1220,16 +1220,16 @@ func testConstants2(t *testing.T, expected []interface{}, actual []object.Object
 			)
 
 		case string:
-			assert.Equal(constant, actual[i].(*object.String).Value)
+			assert.Equal(constant, actual[i].(object.String).Value)
 
 		case int:
-			assert.Equal(int64(constant), actual[i].(*object.Integer).Value)
+			assert.Equal(int64(constant), actual[i].(object.Integer).Value)
 		}
 	}
 }
 
 func testIntegerObject(expected int64, actual object.Object) interface{} {
-	result, ok := actual.(*object.Integer)
+	result, ok := actual.(object.Integer)
 	if !ok {
 		return fmt.Errorf("object is not Integer. got=%T (%+v", actual, actual)
 	}
@@ -1242,7 +1242,7 @@ func testIntegerObject(expected int64, actual object.Object) interface{} {
 }
 
 func testStringObject(expected string, actual object.Object) error {
-	result, ok := actual.(*object.String)
+	result, ok := actual.(object.String)
 	if !ok {
 		return fmt.Errorf("object is not String. got %T (%+v", actual, actual)
 	}
diff --git a/internal/evaluator/evaluator.go b/internal/evaluator/evaluator.go
index 54fbc4a..ba4937e 100644
--- a/internal/evaluator/evaluator.go
+++ b/internal/evaluator/evaluator.go
@@ -13,9 +13,9 @@ import (
 )
 
 var (
-	NULL  = &object.Null{}
-	TRUE  = &object.Boolean{Value: true}
-	FALSE = &object.Boolean{Value: false}
+	NULL  = object.Null{}
+	TRUE  = object.Boolean{Value: true}
+	FALSE = object.Boolean{Value: false}
 )
 
 func isError(obj object.Object) bool {
@@ -52,7 +52,7 @@ func Eval(node ast.Node, env *object.Environment) object.Object {
 		if isError(val) {
 			return val
 		}
-		return &object.ReturnValue{Value: val}
+		return object.ReturnValue{Value: val}
 
 	case *ast.BindExpression:
 		value := Eval(node.Value, env)
@@ -95,7 +95,7 @@ func Eval(node ast.Node, env *object.Environment) object.Object {
 				if isError(index) {
 					return index
 				}
-				if idx, ok := index.(*object.Integer); ok {
+				if idx, ok := index.(object.Integer); ok {
 					array.Elements[idx.Value] = value
 				} else {
 					return newError("cannot index array with %#v", index)
@@ -130,7 +130,7 @@ func Eval(node ast.Node, env *object.Environment) object.Object {
 
 	// Expressions
 	case *ast.IntegerLiteral:
-		return &object.Integer{Value: node.Value}
+		return object.Integer{Value: node.Value}
 
 	case *ast.Boolean:
 		return nativeBoolToBooleanObject(node.Value)
@@ -169,7 +169,7 @@ func Eval(node ast.Node, env *object.Environment) object.Object {
 		return applyFunction(function, args)
 
 	case *ast.StringLiteral:
-		return &object.String{Value: node.Value}
+		return object.String{Value: node.Value}
 
 	case *ast.ArrayLiteral:
 		elements := evalExpressions(node.Elements, env)
@@ -203,12 +203,12 @@ func evalImportExpression(ie *ast.ImportExpression, env *object.Environment) obj
 		return name
 	}
 
-	if s, ok := name.(*object.String); ok {
+	if s, ok := name.(object.String); ok {
 		attrs := EvalModule(s.Value)
 		if isError(attrs) {
 			return attrs
 		}
-		return &object.Module{Name: s.Value, Attrs: attrs}
+		return object.Module{Name: s.Value, Attrs: attrs}
 	}
 	return newError("ImportError: invalid import path '%s'", name)
 }
@@ -243,9 +243,9 @@ func evalProgram(program *ast.Program, env *object.Environment) object.Object {
 		result = Eval(statement, env)
 
 		switch result := result.(type) {
-		case *object.ReturnValue:
+		case object.ReturnValue:
 			return result.Value
-		case *object.Error:
+		case object.Error:
 			return result
 		}
 
@@ -271,7 +271,7 @@ func evalBlockStatements(block *ast.BlockStatement, env *object.Environment) obj
 	return result
 }
 
-func nativeBoolToBooleanObject(input bool) object.Object {
+func nativeBoolToBooleanObject(input bool) object.Boolean {
 	if input {
 		return TRUE
 	}
@@ -314,14 +314,14 @@ func evalIntegerPrefixOperatorExpression(operator string, right object.Object) o
 		return newError("unknown operator: -%s", right.Type())
 	}
 
-	value := right.(*object.Integer).Value
+	value := right.(object.Integer).Value
 	switch operator {
 	case "!":
 		return FALSE
 	case "~":
-		return &object.Integer{Value: ^value}
+		return object.Integer{Value: ^value}
 	case "-":
-		return &object.Integer{Value: -value}
+		return object.Integer{Value: -value}
 	default:
 		return newError("unknown operator: %s", operator)
 	}
@@ -354,7 +354,7 @@ func evalInfixExpression(operator string, left, right object.Object) object.Obje
 	// [1] * 3
 	case operator == "*" && left.Type() == object.ArrayType && right.Type() == object.IntegerType:
 		leftVal := left.(*object.Array).Elements
-		rightVal := int(right.(*object.Integer).Value)
+		rightVal := int(right.(object.Integer).Value)
 		elements := leftVal
 		for i := rightVal; i > 1; i-- {
 			elements = append(elements, leftVal...)
@@ -363,7 +363,7 @@ func evalInfixExpression(operator string, left, right object.Object) object.Obje
 
 	// 3 * [1]
 	case operator == "*" && left.Type() == object.IntegerType && right.Type() == object.ArrayType:
-		leftVal := int(left.(*object.Integer).Value)
+		leftVal := int(left.(object.Integer).Value)
 		rightVal := right.(*object.Array).Elements
 		elements := rightVal
 		for i := leftVal; i > 1; i-- {
@@ -373,15 +373,15 @@ func evalInfixExpression(operator string, left, right object.Object) object.Obje
 
 	// " " * 4
 	case operator == "*" && left.Type() == object.StringType && right.Type() == object.IntegerType:
-		leftVal := left.(*object.String).Value
-		rightVal := right.(*object.Integer).Value
-		return &object.String{Value: strings.Repeat(leftVal, int(rightVal))}
+		leftVal := left.(object.String).Value
+		rightVal := right.(object.Integer).Value
+		return object.String{Value: strings.Repeat(leftVal, int(rightVal))}
 
 	// 4 * " "
 	case operator == "*" && left.Type() == object.IntegerType && right.Type() == object.StringType:
-		leftVal := left.(*object.Integer).Value
-		rightVal := right.(*object.String).Value
-		return &object.String{Value: strings.Repeat(rightVal, int(leftVal))}
+		leftVal := left.(object.Integer).Value
+		rightVal := right.(object.String).Value
+		return object.String{Value: strings.Repeat(rightVal, int(leftVal))}
 
 	case operator == "==":
 		return nativeBoolToBooleanObject(left.(object.Comparable).Compare(right) == 0)
@@ -409,8 +409,8 @@ func evalInfixExpression(operator string, left, right object.Object) object.Obje
 }
 
 func evalBooleanInfixExpression(operator string, left, right object.Object) object.Object {
-	leftVal := left.(*object.Boolean).Value
-	rightVal := right.(*object.Boolean).Value
+	leftVal := left.(object.Boolean).Value
+	rightVal := right.(object.Boolean).Value
 
 	switch operator {
 	case "&&":
@@ -423,42 +423,42 @@ func evalBooleanInfixExpression(operator string, left, right object.Object) obje
 }
 
 func evalStringInfixExpression(operator string, left object.Object, right object.Object) object.Object {
-	leftVal := left.(*object.String).Value
-	rightVal := right.(*object.String).Value
+	leftVal := left.(object.String).Value
+	rightVal := right.(object.String).Value
 
 	switch operator {
 	case "+":
-		return &object.String{Value: leftVal + rightVal}
+		return object.String{Value: leftVal + rightVal}
 	default:
 		return newError("unknown operator: %s %s %s", left.Type(), operator, right.Type())
 	}
 }
 
 func evalIntegerInfixExpression(operator string, left, right object.Object) object.Object {
-	leftVal := left.(*object.Integer).Value
-	rightVal := right.(*object.Integer).Value
+	leftVal := left.(object.Integer).Value
+	rightVal := right.(object.Integer).Value
 
 	switch operator {
 	case "+":
-		return &object.Integer{Value: leftVal + rightVal}
+		return object.Integer{Value: leftVal + rightVal}
 	case "-":
-		return &object.Integer{Value: leftVal - rightVal}
+		return object.Integer{Value: leftVal - rightVal}
 	case "*":
-		return &object.Integer{Value: leftVal * rightVal}
+		return object.Integer{Value: leftVal * rightVal}
 	case "/":
-		return &object.Integer{Value: leftVal / rightVal}
+		return object.Integer{Value: leftVal / rightVal}
 	case "%":
-		return &object.Integer{Value: leftVal % rightVal}
+		return object.Integer{Value: leftVal % rightVal}
 	case "|":
-		return &object.Integer{Value: leftVal | rightVal}
+		return object.Integer{Value: leftVal | rightVal}
 	case "^":
-		return &object.Integer{Value: leftVal ^ rightVal}
+		return object.Integer{Value: leftVal ^ rightVal}
 	case "&":
-		return &object.Integer{Value: leftVal & rightVal}
+		return object.Integer{Value: leftVal & rightVal}
 	case "<<":
-		return &object.Integer{Value: leftVal << uint64(rightVal)}
+		return object.Integer{Value: leftVal << uint64(rightVal)}
 	case ">>":
-		return &object.Integer{Value: leftVal >> uint64(rightVal)}
+		return object.Integer{Value: leftVal >> uint64(rightVal)}
 	case "<":
 		return nativeBoolToBooleanObject(leftVal < rightVal)
 	case "<=":
@@ -504,11 +504,11 @@ func isTruthy(obj object.Object) bool {
 	}
 }
 
-func newError(format string, a ...interface{}) *object.Error {
-	return &object.Error{Message: fmt.Sprintf(format, a...)}
+func newError(format string, a ...interface{}) object.Error {
+	return object.Error{Message: fmt.Sprintf(format, a...)}
 }
 
-// EvalModule evaluates the named module and returns a *object.Module objec
+// EvalModule evaluates the named module and returns a object.Module objec
 func EvalModule(name string) object.Object {
 	filename := utils.FindModule(name)
 
@@ -588,7 +588,7 @@ func extendFunctionEnv(fn *object.Function, args []object.Object) *object.Enviro
 }
 
 func unwrapReturnValue(obj object.Object) object.Object {
-	if returnValue, ok := obj.(*object.ReturnValue); ok {
+	if returnValue, ok := obj.(object.ReturnValue); ok {
 		return returnValue.Value
 	}
 
@@ -611,20 +611,20 @@ func evalIndexExpression(left, index object.Object) object.Object {
 }
 
 func EvalModuleIndexExpression(module, index object.Object) object.Object {
-	moduleObject := module.(*object.Module)
+	moduleObject := module.(object.Module)
 	return evalHashIndexExpression(moduleObject.Attrs, index)
 }
 
 func evalStringIndexExpression(str, index object.Object) object.Object {
-	stringObject := str.(*object.String)
-	idx := index.(*object.Integer).Value
+	stringObject := str.(object.String)
+	idx := index.(object.Integer).Value
 	max := int64((len(stringObject.Value)) - 1)
 
 	if idx < 0 || idx > max {
-		return &object.String{Value: ""}
+		return object.String{Value: ""}
 	}
 
-	return &object.String{Value: string(stringObject.Value[idx])}
+	return object.String{Value: string(stringObject.Value[idx])}
 }
 
 func evalHashIndexExpression(hash, index object.Object) object.Object {
@@ -645,7 +645,7 @@ func evalHashIndexExpression(hash, index object.Object) object.Object {
 
 func evalArrayIndexExpression(array, index object.Object) object.Object {
 	arrayObject := array.(*object.Array)
-	idx := index.(*object.Integer).Value
+	idx := index.(object.Integer).Value
 	maxInx := int64(len(arrayObject.Elements) - 1)
 
 	if idx < 0 || idx > maxInx {
diff --git a/internal/evaluator/evaluator_test.go b/internal/evaluator/evaluator_test.go
index 49f6e3a..3e10172 100644
--- a/internal/evaluator/evaluator_test.go
+++ b/internal/evaluator/evaluator_test.go
@@ -25,25 +25,25 @@ func assertEvaluated(t *testing.T, expected interface{}, actual object.Object) {
 
 	switch expected.(type) {
 	case nil:
-		if _, ok := actual.(*object.Null); ok {
+		if _, ok := actual.(object.Null); ok {
 			assert.True(ok)
 		} else {
 			assert.Equal(expected, actual)
 		}
 	case int:
-		if i, ok := actual.(*object.Integer); ok {
+		if i, ok := actual.(object.Integer); ok {
 			assert.Equal(int64(expected.(int)), i.Value)
 		} else {
 			assert.Equal(expected, actual)
 		}
 	case error:
-		if e, ok := actual.(*object.Integer); ok {
+		if e, ok := actual.(object.Integer); ok {
 			assert.Equal(expected.(error).Error(), e.Value)
 		} else {
 			assert.Equal(expected, actual)
 		}
 	case string:
-		if s, ok := actual.(*object.String); ok {
+		if s, ok := actual.(object.String); ok {
 			assert.Equal(expected.(string), s.Value)
 		} else {
 			assert.Equal(expected, actual)
@@ -161,7 +161,6 @@ func TestIfElseExpression(t *testing.T) {
 	}
 
 	for _, tt := range tests {
-		t.Log(tt.input)
 		evaluated := testEval(tt.input)
 		integer, ok := tt.expected.(int)
 		if ok {
@@ -279,7 +278,7 @@ func TestErrorHandling(t *testing.T) {
 	for _, tt := range tests {
 		evaluated := testEval(tt.input)
 
-		errObj, ok := evaluated.(*object.Error)
+		errObj, ok := evaluated.(object.Error)
 		if !ok {
 			t.Errorf("no error object returned. got=%T(%+v)",
 				evaluated, evaluated)
@@ -409,7 +408,7 @@ func TestStringLiteral(t *testing.T) {
 	input := `"Hello World!"`
 
 	evaluated := testEval(input)
-	str, ok := evaluated.(*object.String)
+	str, ok := evaluated.(object.String)
 	if !ok {
 		t.Fatalf("object is not String. got=%T (+%v)", evaluated, evaluated)
 	}
@@ -423,7 +422,7 @@ func TestStringConcatenation(t *testing.T) {
 	input := `"Hello" + " " + "World!"`
 
 	evaluated := testEval(input)
-	str, ok := evaluated.(*object.String)
+	str, ok := evaluated.(object.String)
 	if !ok {
 		t.Fatalf("object is not String. got=%T (+%v)", evaluated, evaluated)
 	}
@@ -495,7 +494,7 @@ func TestBuiltinFunctions(t *testing.T) {
 		case string:
 			testStringObject(t, evaluated, expected)
 		case error:
-			errObj, ok := evaluated.(*object.Error)
+			errObj, ok := evaluated.(object.Error)
 			if !ok {
 				t.Errorf("object is not Error. got=%T (%+v)",
 					evaluated, evaluated)
@@ -641,12 +640,12 @@ func TestHashLiterals(t *testing.T) {
 	}
 
 	expected := map[object.HashKey]int64{
-		(&object.String{Value: "one"}).HashKey():   1,
-		(&object.String{Value: "two"}).HashKey():   2,
-		(&object.String{Value: "three"}).HashKey(): 3,
-		(&object.Integer{Value: 4}).HashKey():      4,
-		TRUE.HashKey():                             5,
-		FALSE.HashKey():                            6,
+		(object.String{Value: "one"}).HashKey():   1,
+		(object.String{Value: "two"}).HashKey():   2,
+		(object.String{Value: "three"}).HashKey(): 3,
+		(object.Integer{Value: 4}).HashKey():      4,
+		TRUE.HashKey():                            5,
+		FALSE.HashKey():                           6,
 	}
 
 	if len(result.Pairs) != len(expected) {
@@ -672,8 +671,8 @@ func TestHashMerging(t *testing.T) {
 	}
 
 	expected := map[object.HashKey]int64{
-		(&object.String{Value: "a"}).HashKey(): 1,
-		(&object.String{Value: "b"}).HashKey(): 2,
+		(object.String{Value: "a"}).HashKey(): 1,
+		(object.String{Value: "b"}).HashKey(): 2,
 	}
 
 	if len(result.Pairs) != len(expected) {
@@ -804,7 +803,7 @@ func testEval(input string) object.Object {
 }
 
 func testIntegerObject(t *testing.T, obj object.Object, expected int64) bool {
-	result, ok := obj.(*object.Integer)
+	result, ok := obj.(object.Integer)
 	if !ok {
 		t.Errorf("object is not Integer. got=%T (%+v)", obj, obj)
 		return false
@@ -823,7 +822,7 @@ func TestNullExpression(t *testing.T) {
 }
 
 func testBooleanObject(t *testing.T, obj object.Object, expected bool) bool {
-	result, ok := obj.(*object.Boolean)
+	result, ok := obj.(object.Boolean)
 	if !ok {
 		t.Errorf("object is not Boolean. got=%T (%+v)", obj, obj)
 		return false
@@ -845,7 +844,7 @@ func testNullObject(t *testing.T, obj object.Object) bool {
 }
 
 func testStringObject(t *testing.T, obj object.Object, expected string) bool {
-	result, ok := obj.(*object.String)
+	result, ok := obj.(object.String)
 	if !ok {
 		t.Errorf("object is not String. got=%T (%+v)", obj, obj)
 		return false
diff --git a/internal/lexer/lexer.go b/internal/lexer/lexer.go
index e5d5092..7fb3f5e 100644
--- a/internal/lexer/lexer.go
+++ b/internal/lexer/lexer.go
@@ -232,7 +232,7 @@ func (l *Lexer) skipWhitespace() {
 }
 
 func (l *Lexer) readString() (string, error) {
-	b := &strings.Builder{}
+	b := strings.Builder{}
 	for {
 		l.readChar()
 		if l.ch == '\\' {
diff --git a/internal/object/array.go b/internal/object/array.go
index aced0e5..e8c24e1 100644
--- a/internal/object/array.go
+++ b/internal/object/array.go
@@ -25,7 +25,7 @@ func (ao *Array) PopLeft() Object {
 		ao.Elements = ao.Elements[1:]
 		return e
 	}
-	return &Null{}
+	return Null{}
 }
 
 func (ao *Array) PopRight() Object {
@@ -34,7 +34,7 @@ func (ao *Array) PopRight() Object {
 		ao.Elements = ao.Elements[:(len(ao.Elements) - 1)]
 		return e
 	}
-	return &Null{}
+	return Null{}
 }
 
 func (ao *Array) Prepend(obj Object) {
@@ -89,7 +89,7 @@ func (ao *Array) Mul(other Object) (Object, error) {
 	}
 
 	var elements []Object
-	N := int(other.(*Integer).Value)
+	N := int(other.(Integer).Value)
 	for i := 0; i < N; i++ {
 		elements = append(elements, ao.Elements...)
 	}
@@ -102,10 +102,10 @@ func (ao *Array) Get(index Object) (Object, error) {
 		return nil, fmt.Errorf("invalid type for array index, expected Integer got %s", index.Type())
 	}
 
-	i := index.(*Integer).Value
+	i := index.(Integer).Value
 	N := int64(len(ao.Elements))
 	if i < 0 || i >= N {
-		return &Null{}, nil
+		return Null{}, nil
 	}
 
 	return ao.Elements[i], nil
@@ -116,7 +116,7 @@ func (ao *Array) Set(index, other Object) error {
 		return fmt.Errorf("invalid type for array index, expected Integer got %s", index.Type())
 	}
 
-	i := index.(*Integer).Value
+	i := index.(Integer).Value
 	N := int64(len(ao.Elements))
 	if i < 0 || i >= N {
 		return fmt.Errorf("index out of bounds %d with array length %d", i, N)
diff --git a/internal/object/bool.go b/internal/object/bool.go
index dac75a9..0948706 100644
--- a/internal/object/bool.go
+++ b/internal/object/bool.go
@@ -8,53 +8,53 @@ type Boolean struct {
 	Value bool
 }
 
-func (b *Boolean) Bool() bool {
+func (b Boolean) Bool() bool {
 	return b.Value
 }
 
-func (b *Boolean) Type() Type {
+func (b Boolean) Type() Type {
 	return BooleanType
 }
 
-func (b *Boolean) Inspect() string {
+func (b Boolean) Inspect() string {
 	return fmt.Sprintf("%t", b.Value)
 }
 
-func (b *Boolean) Clone() Object {
-	return &Boolean{Value: b.Value}
+func (b Boolean) Clone() Object {
+	return Boolean{Value: b.Value}
 }
 
-func (b *Boolean) String() string {
+func (b Boolean) String() string {
 	return b.Inspect()
 }
 
-func (b *Boolean) Int() int {
+func (b Boolean) Int() int {
 	if b.Value {
 		return 1
 	}
 	return 0
 }
 
-func (b *Boolean) LogicalAnd(other Object) (Object, error) {
+func (b Boolean) LogicalAnd(other Object) (Object, error) {
 	if !AssertTypes(other, BooleanType, IntegerType) {
 		return nil, NewBinaryOpError(b, other, "&&")
 	}
-	return &Boolean{b.Value && other.Bool()}, nil
+	return Boolean{b.Value && other.Bool()}, nil
 }
 
-func (b *Boolean) LogicalOr(other Object) (Object, error) {
+func (b Boolean) LogicalOr(other Object) (Object, error) {
 	if !AssertTypes(other, BooleanType, IntegerType) {
 		return nil, NewBinaryOpError(b, other, "||")
 	}
-	return &Boolean{b.Value || other.Bool()}, nil
+	return Boolean{b.Value || other.Bool()}, nil
 }
 
-func (b *Boolean) LogicalNot() Object {
-	return &Boolean{!b.Value}
+func (b Boolean) LogicalNot() Object {
+	return Boolean{!b.Value}
 }
 
-func (b *Boolean) Compare(other Object) int {
-	if obj, ok := other.(*Boolean); ok {
+func (b Boolean) Compare(other Object) int {
+	if obj, ok := other.(Boolean); ok {
 		return b.Int() - obj.Int()
 	}
 	return 1
diff --git a/internal/object/environment.go b/internal/object/environment.go
index 83fcc1d..7d98b4c 100644
--- a/internal/object/environment.go
+++ b/internal/object/environment.go
@@ -39,7 +39,7 @@ func (e *Environment) ExportedHash() *Hash {
 	pairs := make(map[HashKey]HashPair)
 	for k, v := range e.store {
 		if unicode.IsUpper(rune(k[0])) {
-			s := &String{Value: k}
+			s := String{Value: k}
 			pairs[s.HashKey()] = HashPair{Key: s, Value: v}
 		}
 	}
diff --git a/internal/object/error.go b/internal/object/error.go
index 1764530..c06d632 100644
--- a/internal/object/error.go
+++ b/internal/object/error.go
@@ -6,22 +6,22 @@ type Error struct {
 	Message string
 }
 
-func (e *Error) Bool() bool {
+func (e Error) Bool() bool {
 	return false
 }
 
-func (e *Error) Type() Type {
+func (e Error) Type() Type {
 	return ErrorType
 }
 
-func (e *Error) Inspect() string {
+func (e Error) Inspect() string {
 	return "Error: " + e.Message
 }
 
-func (e *Error) Clone() Object {
-	return &Error{Message: e.Message}
+func (e Error) Clone() Object {
+	return Error{Message: e.Message}
 }
 
-func (e *Error) String() string {
+func (e Error) String() string {
 	return e.Message
 }
diff --git a/internal/object/function.go b/internal/object/function.go
index c6e7406..b56c07f 100644
--- a/internal/object/function.go
+++ b/internal/object/function.go
@@ -12,15 +12,15 @@ type Function struct {
 	Env        *Environment
 }
 
-func (f *Function) Bool() bool {
+func (f Function) Bool() bool {
 	return false
 }
 
-func (f *Function) Type() Type {
+func (f Function) Type() Type {
 	return FunctionType
 }
 
-func (f *Function) Inspect() string {
+func (f Function) Inspect() string {
 	var out bytes.Buffer
 
 	params := []string{}
@@ -38,7 +38,7 @@ func (f *Function) Inspect() string {
 	return out.String()
 }
 
-func (f *Function) String() string {
+func (f Function) String() string {
 	return f.Inspect()
 }
 
@@ -46,18 +46,18 @@ type ReturnValue struct {
 	Value Object
 }
 
-func (rv *ReturnValue) Bool() bool {
+func (rv ReturnValue) Bool() bool {
 	return true
 }
 
-func (rv *ReturnValue) Type() Type {
+func (rv ReturnValue) Type() Type {
 	return ReturnType
 }
 
-func (rv *ReturnValue) Inspect() string {
+func (rv ReturnValue) Inspect() string {
 	return rv.Value.Inspect()
 }
 
-func (rv *ReturnValue) String() string {
+func (rv ReturnValue) String() string {
 	return rv.Inspect()
 }
diff --git a/internal/object/hash.go b/internal/object/hash.go
index 8966587..6ef3a39 100644
--- a/internal/object/hash.go
+++ b/internal/object/hash.go
@@ -12,7 +12,7 @@ type HashKey struct {
 	Value uint64
 }
 
-func (b *Boolean) HashKey() HashKey {
+func (b Boolean) HashKey() HashKey {
 	var value uint64
 
 	if b.Value {
@@ -24,11 +24,11 @@ func (b *Boolean) HashKey() HashKey {
 	return HashKey{Type: b.Type(), Value: value}
 }
 
-func (i *Integer) HashKey() HashKey {
+func (i Integer) HashKey() HashKey {
 	return HashKey{Type: i.Type(), Value: uint64(i.Value)}
 }
 
-func (s *String) HashKey() HashKey {
+func (s String) HashKey() HashKey {
 	h := fnv.New64a()
 	h.Write([]byte(s.Value))
 
@@ -98,7 +98,7 @@ func (h *Hash) Get(index Object) (Object, error) {
 
 	pair, found := h.Pairs[key.HashKey()]
 	if !found {
-		return &Null{}, nil
+		return Null{}, nil
 	}
 
 	return pair.Value, nil
diff --git a/internal/object/int.go b/internal/object/int.go
index 34e9df5..5a7c06e 100644
--- a/internal/object/int.go
+++ b/internal/object/int.go
@@ -6,44 +6,44 @@ type Integer struct {
 	Value int64
 }
 
-func (i *Integer) Bool() bool {
+func (i Integer) Bool() bool {
 	return i.Value != 0
 }
 
-func (i *Integer) Type() Type {
+func (i Integer) Type() Type {
 	return IntegerType
 }
 
-func (i *Integer) Inspect() string {
+func (i Integer) Inspect() string {
 	return fmt.Sprintf("%d", i.Value)
 }
 
-func (i *Integer) Clone() Object {
-	return &Integer{Value: i.Value}
+func (i Integer) Clone() Object {
+	return Integer{Value: i.Value}
 }
 
-func (i *Integer) String() string {
+func (i Integer) String() string {
 	return i.Inspect()
 }
 
-func (i *Integer) Add(other Object) (Object, error) {
+func (i Integer) Add(other Object) (Object, error) {
 	if !AssertTypes(other, IntegerType) {
 		return nil, NewBinaryOpError(i, other, "+")
 	}
-	return &Integer{i.Value + other.(*Integer).Value}, nil
+	return Integer{i.Value + other.(Integer).Value}, nil
 }
 
-func (i *Integer) Sub(other Object) (Object, error) {
+func (i Integer) Sub(other Object) (Object, error) {
 	if !AssertTypes(other, IntegerType) {
 		return nil, NewBinaryOpError(i, other, "-")
 	}
-	return &Integer{i.Value - other.(*Integer).Value}, nil
+	return Integer{i.Value - other.(Integer).Value}, nil
 }
 
-func (i *Integer) Mul(other Object) (Object, error) {
+func (i Integer) Mul(other Object) (Object, error) {
 	switch other.Type() {
 	case IntegerType:
-		return &Integer{i.Value * other.(*Integer).Value}, nil
+		return Integer{i.Value * other.(Integer).Value}, nil
 	case StringType:
 		return other.(Mul).Mul(i)
 	case ArrayType:
@@ -53,69 +53,69 @@ func (i *Integer) Mul(other Object) (Object, error) {
 	}
 }
 
-func (i *Integer) Div(other Object) (Object, error) {
+func (i Integer) Div(other Object) (Object, error) {
 	if !AssertTypes(other, IntegerType) {
 		return nil, NewBinaryOpError(i, other, "/")
 	}
-	return &Integer{i.Value / other.(*Integer).Value}, nil
+	return Integer{i.Value / other.(Integer).Value}, nil
 }
 
-func (i *Integer) Mod(other Object) (Object, error) {
+func (i Integer) Mod(other Object) (Object, error) {
 	if !AssertTypes(other, IntegerType) {
 		return nil, NewBinaryOpError(i, other, "%")
 	}
-	return &Integer{i.Value % other.(*Integer).Value}, nil
+	return Integer{i.Value % other.(Integer).Value}, nil
 }
 
-func (i *Integer) BitwiseOr(other Object) (Object, error) {
+func (i Integer) BitwiseOr(other Object) (Object, error) {
 	if !AssertTypes(other, IntegerType) {
 		return nil, NewBinaryOpError(i, other, "|")
 	}
-	return &Integer{i.Value | other.(*Integer).Value}, nil
+	return Integer{i.Value | other.(Integer).Value}, nil
 }
 
-func (i *Integer) BitwiseXor(other Object) (Object, error) {
+func (i Integer) BitwiseXor(other Object) (Object, error) {
 	if !AssertTypes(other, IntegerType) {
 		return nil, NewBinaryOpError(i, other, "^")
 	}
-	return &Integer{i.Value ^ other.(*Integer).Value}, nil
+	return Integer{i.Value ^ other.(Integer).Value}, nil
 }
 
-func (i *Integer) BitwiseAnd(other Object) (Object, error) {
+func (i Integer) BitwiseAnd(other Object) (Object, error) {
 	if !AssertTypes(other, IntegerType) {
-		return nil, NewBinaryOpError(i, other, "&")
+		return nil, NewBinaryOpError(i, other, "")
 	}
-	return &Integer{i.Value & other.(*Integer).Value}, nil
+	return Integer{i.Value & other.(Integer).Value}, nil
 }
 
-func (i *Integer) BitwiseNot() Object {
-	return &Integer{^i.Value}
+func (i Integer) BitwiseNot() Object {
+	return Integer{^i.Value}
 }
 
-func (i *Integer) LeftShift(other Object) (Object, error) {
+func (i Integer) LeftShift(other Object) (Object, error) {
 	if !AssertTypes(other, IntegerType) {
 		return nil, NewBinaryOpError(i, other, "<<")
 	}
-	return &Integer{i.Value << other.(*Integer).Value}, nil
+	return Integer{i.Value << other.(Integer).Value}, nil
 }
 
-func (i *Integer) RightShift(other Object) (Object, error) {
+func (i Integer) RightShift(other Object) (Object, error) {
 	if !AssertTypes(other, IntegerType) {
 		return nil, NewBinaryOpError(i, other, ">>")
 	}
-	return &Integer{i.Value >> other.(*Integer).Value}, nil
+	return Integer{i.Value >> other.(Integer).Value}, nil
 }
 
-func (i *Integer) LogicalNot() Object {
-	return &Boolean{!i.Bool()}
+func (i Integer) LogicalNot() Object {
+	return Boolean{!i.Bool()}
 }
 
-func (i *Integer) Negate() Object {
-	return &Integer{-i.Value}
+func (i Integer) Negate() Object {
+	return Integer{-i.Value}
 }
 
-func (i *Integer) Compare(other Object) int {
-	if obj, ok := other.(*Integer); ok {
+func (i Integer) Compare(other Object) int {
+	if obj, ok := other.(Integer); ok {
 		switch {
 		case i.Value < obj.Value:
 			return -1
diff --git a/internal/object/module.go b/internal/object/module.go
index 595f87d..67a068b 100644
--- a/internal/object/module.go
+++ b/internal/object/module.go
@@ -24,7 +24,7 @@ func (m Module) Inspect() string {
 	return fmt.Sprintf("<module '%s'>", m.Name)
 }
 
-func (m *Module) Get(index Object) (Object, error) {
+func (m Module) Get(index Object) (Object, error) {
 	key, ok := index.(Hashable)
 	if !ok {
 		return nil, fmt.Errorf("invalid module attribute %s", index.Type())
@@ -32,7 +32,7 @@ func (m *Module) Get(index Object) (Object, error) {
 
 	attr, found := m.Attrs.(*Hash).Pairs[key.HashKey()]
 	if !found {
-		return &Null{}, nil
+		return Null{}, nil
 	}
 
 	return attr.Value, nil
diff --git a/internal/object/null.go b/internal/object/null.go
index f0b59cd..50a6a92 100644
--- a/internal/object/null.go
+++ b/internal/object/null.go
@@ -2,28 +2,28 @@ package object
 
 type Null struct{}
 
-func (n *Null) Bool() bool {
+func (n Null) Bool() bool {
 	return false
 }
 
-func (n *Null) Type() Type {
+func (n Null) Type() Type {
 	return NullType
 }
 
-func (n *Null) Inspect() string {
+func (n Null) Inspect() string {
 	return "null"
 }
 
-func (n *Null) String() string {
+func (n Null) String() string {
 	return n.Inspect()
 }
 
-func (n *Null) LogicalNot() Object {
-	return &Boolean{!n.Bool()}
+func (n Null) LogicalNot() Object {
+	return Boolean{!n.Bool()}
 }
 
-func (n *Null) Compare(other Object) int {
-	if _, ok := other.(*Null); ok {
+func (n Null) Compare(other Object) int {
+	if _, ok := other.(Null); ok {
 		return 0
 	}
 	return 1
diff --git a/internal/object/object_test.go b/internal/object/object_test.go
index c52b0a6..b74aa87 100644
--- a/internal/object/object_test.go
+++ b/internal/object/object_test.go
@@ -3,10 +3,10 @@ package object
 import "testing"
 
 func TestStringHashKey(t *testing.T) {
-	hello1 := &String{Value: "Hello World"}
-	hello2 := &String{Value: "Hello World"}
-	diff1 := &String{Value: "My name is johnny"}
-	diff2 := &String{Value: "My name is johnny"}
+	hello1 := String{Value: "Hello World"}
+	hello2 := String{Value: "Hello World"}
+	diff1 := String{Value: "My name is johnny"}
+	diff2 := String{Value: "My name is johnny"}
 
 	if hello1.HashKey() != hello2.HashKey() {
 		t.Errorf("string with same content have different hash keys")
diff --git a/internal/object/str.go b/internal/object/str.go
index fab48e1..6809e82 100644
--- a/internal/object/str.go
+++ b/internal/object/str.go
@@ -10,59 +10,59 @@ type String struct {
 	Value string
 }
 
-func (s *String) Len() int {
+func (s String) Len() int {
 	return utf8.RuneCountInString(s.Value)
 }
 
-func (s *String) Bool() bool {
+func (s String) Bool() bool {
 	return s.Value != ""
 }
 
-func (s *String) Type() Type {
+func (s String) Type() Type {
 	return StringType
 }
 
-func (s *String) Inspect() string {
+func (s String) Inspect() string {
 	return fmt.Sprintf("%#v", s.Value)
 }
 
-func (s *String) Clone() Object {
-	return &String{Value: s.Value}
+func (s String) Clone() Object {
+	return String{Value: s.Value}
 }
 
-func (s *String) String() string {
+func (s String) String() string {
 	return s.Value
 }
 
-func (s *String) Add(other Object) (Object, error) {
+func (s String) Add(other Object) (Object, error) {
 	if !AssertTypes(other, StringType) {
 		return nil, NewBinaryOpError(s, other, "+")
 	}
-	return &String{s.Value + other.(*String).Value}, nil
+	return String{s.Value + other.(String).Value}, nil
 }
 
-func (s *String) Mul(other Object) (Object, error) {
+func (s String) Mul(other Object) (Object, error) {
 	if !AssertTypes(other, IntegerType) {
 		return nil, NewBinaryOpError(s, other, "*")
 	}
-	return &String{strings.Repeat(s.Value, int(other.(*Integer).Value))}, nil
+	return String{strings.Repeat(s.Value, int(other.(Integer).Value))}, nil
 }
 
-func (s *String) Get(index Object) (Object, error) {
+func (s String) Get(index Object) (Object, error) {
 	if !AssertTypes(index, IntegerType) {
 		return nil, fmt.Errorf("invalid type for string index, expected Integer got %s", index.Type())
 	}
 
-	i := int(index.(*Integer).Value)
+	i := int(index.(Integer).Value)
 	if i < 0 || i >= len(s.Value) {
-		return &String{}, nil
+		return String{}, nil
 	}
 
-	return &String{string(s.Value[i])}, nil
+	return String{string(s.Value[i])}, nil
 }
 
-func (s *String) Compare(other Object) int {
-	if obj, ok := other.(*String); ok {
+func (s String) Compare(other Object) int {
+	if obj, ok := other.(String); ok {
 		switch {
 		case s.Value < obj.Value:
 			return -1
diff --git a/internal/plugins/hello.go b/internal/plugins/hello.go
index f91f6c8..ee219af 100644
--- a/internal/plugins/hello.go
+++ b/internal/plugins/hello.go
@@ -4,5 +4,5 @@ import "monkey/internal/object"
 
 // Hello ...
 func Hello(args ...object.Object) object.Object {
-	return &object.String{Value: "Hello World!"}
+	return object.String{Value: "Hello World!"}
 }
diff --git a/internal/vm/frame.go b/internal/vm/frame.go
index 5a564a2..6ffc14d 100644
--- a/internal/vm/frame.go
+++ b/internal/vm/frame.go
@@ -11,23 +11,39 @@ type Frame struct {
 	basePointer int
 }
 
-func NewFrame(cl *object.Closure, basePointer int) *Frame {
-	return &Frame{
+func NewFrame(cl *object.Closure, basePointer int) Frame {
+	return Frame{
 		cl:          cl,
 		basePointer: basePointer,
 	}
 }
 
+func (f *Frame) Closure() *object.Closure {
+	return f.cl
+}
+
+func (f *Frame) GetFree(idx uint8) object.Object {
+	return f.cl.Free[idx]
+}
+
+func (f *Frame) SetFree(idx uint8, obj object.Object) {
+	f.cl.Free[idx] = obj
+}
+
+func (f *Frame) SetIP(ip int) {
+	f.ip = ip
+}
+
+func (f Frame) PeekNextOp() code.Opcode {
+	return code.Opcode(f.cl.Fn.Instructions[f.ip])
+}
+
 func (f *Frame) ReadNextOp() code.Opcode {
 	op := code.Opcode(f.cl.Fn.Instructions[f.ip])
 	f.ip++
 	return op
 }
 
-func (f *Frame) PeekNextOp() code.Opcode {
-	return code.Opcode(f.cl.Fn.Instructions[f.ip])
-}
-
 func (f *Frame) ReadUint8() uint8 {
 	n := code.ReadUint8(f.cl.Fn.Instructions[f.ip:])
 	f.ip++
@@ -40,6 +56,6 @@ func (f *Frame) ReadUint16() uint16 {
 	return n
 }
 
-func (f *Frame) Instructions() code.Instructions {
+func (f Frame) Instructions() code.Instructions {
 	return f.cl.Fn.Instructions
 }
diff --git a/internal/vm/vm.go b/internal/vm/vm.go
index c1b316c..9c0a19d 100644
--- a/internal/vm/vm.go
+++ b/internal/vm/vm.go
@@ -20,17 +20,17 @@ const StackSize = 2048
 const GlobalsSize = 65536
 const MaxFrames = 1024
 
-var Null = &object.Null{}
-var True = &object.Boolean{Value: true}
-var False = &object.Boolean{Value: false}
+var Null = object.Null{}
+var True = object.Boolean{Value: true}
+var False = object.Boolean{Value: false}
 
 func isTruthy(obj object.Object) bool {
 	switch obj := obj.(type) {
 
-	case *object.Boolean:
+	case object.Boolean:
 		return obj.Value
 
-	case *object.Null:
+	case object.Null:
 		return false
 
 	default:
@@ -38,7 +38,7 @@ func isTruthy(obj object.Object) bool {
 	}
 }
 
-// executeModule compiles the named module and returns a *object.Module object
+// executeModule compiles the named module and returns a object.Module object
 func executeModule(name string, state *VMState) (object.Object, error) {
 	filename := utils.FindModule(name)
 	if filename == "" {
@@ -104,7 +104,7 @@ func (s *VMState) ExportedHash() *object.Hash {
 		if unicode.IsUpper(rune(name[0])) {
 			if symbol.Scope == compiler.GlobalScope {
 				obj := s.Globals[symbol.Index]
-				s := &object.String{Value: name}
+				s := object.String{Value: name}
 				pairs[s.HashKey()] = object.HashPair{Key: s, Value: obj}
 			}
 		}
@@ -123,20 +123,21 @@ type VM struct {
 	stack []object.Object
 	sp    int // Always points to the next value. Top of stack is stack[sp-1]
 
-	frames []*Frame
-	frame  *Frame // Current frame or nil
-	fp     int    // Always points to the current frame. Current frame is frames[fp-1]
+	frames []Frame
+	fp     int // Always points to the current frame. Current frame is frames[fp-1]
 }
 
-func (vm *VM) pushFrame(f *Frame) {
-	vm.frame = f
+func (vm *VM) currentFrame() *Frame {
+	return &vm.frames[vm.fp-1]
+}
+
+func (vm *VM) pushFrame(f Frame) {
 	vm.frames[vm.fp] = f
 	vm.fp++
 }
 
-func (vm *VM) popFrame() *Frame {
+func (vm *VM) popFrame() Frame {
 	vm.fp--
-	vm.frame = vm.frames[vm.fp-1]
 	return vm.frames[vm.fp]
 }
 
@@ -146,7 +147,7 @@ func New(fn string, bytecode *compiler.Bytecode) *VM {
 	mainClosure := &object.Closure{Fn: mainFn}
 	mainFrame := NewFrame(mainClosure, 0)
 
-	frames := make([]*Frame, MaxFrames)
+	frames := make([]Frame, MaxFrames)
 	frames[0] = mainFrame
 
 	state := NewVMState()
@@ -159,7 +160,6 @@ func New(fn string, bytecode *compiler.Bytecode) *VM {
 		sp:    0,
 
 		frames: frames,
-		frame:  mainFrame,
 		fp:     1,
 	}
 
@@ -173,14 +173,13 @@ func NewWithState(fn string, bytecode *compiler.Bytecode, state *VMState) *VM {
 	mainClosure := &object.Closure{Fn: mainFn}
 	mainFrame := NewFrame(mainClosure, 0)
 
-	frames := make([]*Frame, MaxFrames)
+	frames := make([]Frame, MaxFrames)
 	frames[0] = mainFrame
 
 	vm := &VM{
 		state: state,
 
 		frames: frames,
-		frame:  mainFrame,
 		fp:     1,
 
 		stack: make([]object.Object, StackSize),
@@ -210,30 +209,30 @@ func (vm *VM) pop() object.Object {
 }
 
 func (vm *VM) executeLoadBuiltin() error {
-	builtinIndex := vm.frame.ReadUint8()
+	builtinIndex := vm.currentFrame().ReadUint8()
 	builtin := builtins.BuiltinsIndex[builtinIndex]
 	return vm.push(builtin)
 }
 
 func (vm *VM) executeConstant() error {
-	constIndex := vm.frame.ReadUint16()
+	constIndex := vm.currentFrame().ReadUint16()
 	return vm.push(vm.state.Constants[constIndex])
 }
 
 func (vm *VM) executeAssignGlobal() error {
-	globalIndex := vm.frame.ReadUint16()
+	globalIndex := vm.currentFrame().ReadUint16()
 	vm.state.Globals[globalIndex] = vm.pop()
 	return vm.push(Null)
 }
 
 func (vm *VM) executeAssignLocal() error {
-	localIndex := vm.frame.ReadUint8()
-	vm.stack[vm.frame.basePointer+int(localIndex)] = vm.pop()
+	localIndex := vm.currentFrame().ReadUint8()
+	vm.stack[vm.currentFrame().basePointer+int(localIndex)] = vm.pop()
 	return vm.push(Null)
 }
 
 func (vm *VM) executeSetGlobal() error {
-	globalIndex := vm.frame.ReadUint16()
+	globalIndex := vm.currentFrame().ReadUint16()
 
 	ref := vm.pop()
 	if immutable, ok := ref.(object.Immutable); ok {
@@ -246,31 +245,31 @@ func (vm *VM) executeSetGlobal() error {
 }
 
 func (vm *VM) executeGetGlobal() error {
-	globalIndex := vm.frame.ReadUint16()
+	globalIndex := vm.currentFrame().ReadUint16()
 	return vm.push(vm.state.Globals[globalIndex])
 }
 
 func (vm *VM) executeSetLocal() error {
-	localIndex := vm.frame.ReadUint8()
+	localIndex := vm.currentFrame().ReadUint8()
 
 	ref := vm.pop()
 	if immutable, ok := ref.(object.Immutable); ok {
-		vm.stack[vm.frame.basePointer+int(localIndex)] = immutable.Clone()
+		vm.stack[vm.currentFrame().basePointer+int(localIndex)] = immutable.Clone()
 	} else {
-		vm.stack[vm.frame.basePointer+int(localIndex)] = ref
+		vm.stack[vm.currentFrame().basePointer+int(localIndex)] = ref
 	}
 
 	return vm.push(Null)
 }
 
 func (vm *VM) executeGetLocal() error {
-	localIndex := vm.frame.ReadUint8()
-	return vm.push(vm.stack[vm.frame.basePointer+int(localIndex)])
+	localIndex := vm.currentFrame().ReadUint8()
+	return vm.push(vm.stack[vm.currentFrame().basePointer+int(localIndex)])
 }
 
 func (vm *VM) executeGetFree() error {
-	freeIndex := vm.frame.ReadUint8()
-	return vm.push(vm.frame.cl.Free[freeIndex])
+	freeIndex := vm.currentFrame().ReadUint8()
+	return vm.push(vm.currentFrame().GetFree(freeIndex))
 }
 
 func (vm *VM) executeLoadModule() error {
@@ -279,7 +278,7 @@ func (vm *VM) executeLoadModule() error {
 }
 
 func (vm *VM) executeCurrentClosure() error {
-	currentClosure := vm.frame.cl
+	currentClosure := vm.currentFrame().cl
 	return vm.push(currentClosure)
 }
 
@@ -316,7 +315,7 @@ func (vm *VM) buildHash(startIndex, endIndex int) (object.Object, error) {
 }
 
 func (vm *VM) executeMakeHash() error {
-	startIndex := vm.sp - int(vm.frame.ReadUint16())
+	startIndex := vm.sp - int(vm.currentFrame().ReadUint16())
 	hash, err := vm.buildHash(startIndex, vm.sp)
 	if err != nil {
 		return err
@@ -336,7 +335,7 @@ func (vm *VM) buildArray(startIndex, endIndex int) (object.Object, error) {
 }
 
 func (vm *VM) executeMakeArray() error {
-	startIndex := vm.sp - int(vm.frame.ReadUint16())
+	startIndex := vm.sp - int(vm.currentFrame().ReadUint16())
 	hash, err := vm.buildArray(startIndex, vm.sp)
 	if err != nil {
 		return err
@@ -346,8 +345,8 @@ func (vm *VM) executeMakeArray() error {
 }
 
 func (vm *VM) executeClosure() error {
-	constIndex := vm.frame.ReadUint16()
-	numFree := vm.frame.ReadUint8()
+	constIndex := vm.currentFrame().ReadUint16()
+	numFree := vm.currentFrame().ReadUint8()
 	return vm.pushClosure(int(constIndex), int(numFree))
 }
 
@@ -659,7 +658,7 @@ func (vm *VM) executeGetItem() error {
 }
 
 func (vm *VM) executeCall() error {
-	args := int(vm.frame.ReadUint8())
+	args := int(vm.currentFrame().ReadUint8())
 
 	callee := vm.stack[vm.sp-1-args]
 	switch callee := callee.(type) {
@@ -685,16 +684,16 @@ func (vm *VM) executeReturn() error {
 }
 
 func (vm *VM) executeJumpIfFalse() error {
-	pos := int(vm.frame.ReadUint16())
+	pos := int(vm.currentFrame().ReadUint16())
 	if !isTruthy(vm.pop()) {
-		vm.frame.ip = pos
+		vm.currentFrame().SetIP(pos)
 	}
 	return nil
 }
 
 func (vm *VM) executeJump() error {
-	pos := int(vm.frame.ReadUint16())
-	vm.frame.ip = pos
+	pos := int(vm.currentFrame().ReadUint16())
+	vm.currentFrame().SetIP(pos)
 	return nil
 }
 
@@ -709,14 +708,14 @@ func (vm *VM) callClosure(cl *object.Closure, numArgs int) error {
 	}
 
 	// Optimize tail calls and avoid a new frame
-	if cl.Fn == vm.frame.cl.Fn {
-		nextOP := vm.frame.PeekNextOp()
+	if cl.Fn == vm.currentFrame().cl.Fn {
+		nextOP := vm.currentFrame().PeekNextOp()
 		if nextOP == code.OpReturn {
 			for p := 0; p < numArgs; p++ {
-				vm.stack[vm.frame.basePointer+p] = vm.stack[vm.sp-numArgs+p]
+				vm.stack[vm.currentFrame().basePointer+p] = vm.stack[vm.sp-numArgs+p]
 			}
 			vm.sp -= numArgs + 1
-			vm.frame.ip = 0 // reset IP to the beginning of the frame
+			vm.currentFrame().SetIP(0) // reset IP to the beginning of the frame
 			return nil
 		}
 	}
@@ -767,7 +766,7 @@ func (vm *VM) pushClosure(constIndex, numFree int) error {
 }
 
 func (vm *VM) loadModule(name object.Object) error {
-	s, ok := name.(*object.String)
+	s, ok := name.(object.String)
 	if !ok {
 		return fmt.Errorf(
 			"TypeError: import() expected argument #1 to be `str` got `%s`",
@@ -780,7 +779,7 @@ func (vm *VM) loadModule(name object.Object) error {
 		return err
 	}
 
-	module := &object.Module{Name: s.Value, Attrs: attrs}
+	module := object.Module{Name: s.Value, Attrs: attrs}
 	return vm.push(module)
 }
 
@@ -799,16 +798,16 @@ func (vm *VM) Run() (err error) {
 	}
 
 	for err == nil {
-		op := vm.frame.ReadNextOp()
+		op := vm.currentFrame().ReadNextOp()
 
 		if vm.Debug {
 			n++
 			log.Printf(
 				"%-25s %-20s\n",
-				fmt.Sprintf("%04d %s", vm.frame.ip, op),
+				fmt.Sprintf("%04d %s", vm.currentFrame().ip, op),
 				fmt.Sprintf(
 					"[ip=%02d fp=%02d, sp=%02d]",
-					vm.frame.ip, vm.fp-1, vm.sp,
+					vm.currentFrame().ip, vm.fp-1, vm.sp,
 				),
 			)
 		}
@@ -953,7 +952,7 @@ func (vm *VM) Run() (err error) {
 		if vm.Debug {
 			log.Printf(
 				"%-25s [ip=%02d fp=%02d, sp=%02d]",
-				"", vm.frame.ip, vm.fp-1, vm.sp,
+				"", vm.currentFrame().ip, vm.fp-1, vm.sp,
 			)
 		}
 	}
diff --git a/internal/vm/vm_test.go b/internal/vm/vm_test.go
index 535fde9..a740951 100644
--- a/internal/vm/vm_test.go
+++ b/internal/vm/vm_test.go
@@ -42,7 +42,7 @@ func runVmTests(t *testing.T, tests []vmTestCase) {
 		//	switch constant := constant.(type) {
 		//	case *object.CompiledFunction:
 		//		fmt.Printf(" Instructions:\n%s", constant.Instructions)
-		//	case *object.Integer:
+		//	case object.Integer:
 		//		fmt.Printf(" Value: %d\n", constant.Value)
 		//	}
 		//
@@ -129,13 +129,13 @@ func testExpectedObject(t *testing.T, expected interface{}, actual object.Object
 			}
 		}
 
-	case *object.Null:
+	case object.Null:
 		if actual != Null {
 			t.Errorf("object is not Null: %T (%+v)", actual, actual)
 		}
 
-	case *object.Error:
-		errObj, ok := actual.(*object.Error)
+	case object.Error:
+		errObj, ok := actual.(object.Error)
 		if !ok {
 			t.Errorf("object is not Error: %T (%+v)", actual, actual)
 			return
@@ -153,7 +153,7 @@ func parse(input string) *ast.Program {
 }
 
 func testIntegerObject(expected int64, actual object.Object) error {
-	result, ok := actual.(*object.Integer)
+	result, ok := actual.(object.Integer)
 	if !ok {
 		return fmt.Errorf("object is not Integer. got=%T (%+v", actual, actual)
 	}
@@ -166,7 +166,7 @@ func testIntegerObject(expected int64, actual object.Object) error {
 }
 
 func testBooleanObject(expected bool, actual object.Object) error {
-	result, ok := actual.(*object.Boolean)
+	result, ok := actual.(object.Boolean)
 	if !ok {
 		return fmt.Errorf("object is not Boolean. got=%T (%+v", actual, actual)
 	}
@@ -179,7 +179,7 @@ func testBooleanObject(expected bool, actual object.Object) error {
 }
 
 func testStringObject(expected string, actual object.Object) error {
-	result, ok := actual.(*object.String)
+	result, ok := actual.(object.String)
 	if !ok {
 		return fmt.Errorf("object is not String. got=%T (%+v", actual, actual)
 	}
@@ -379,15 +379,15 @@ func TestHashLiterals(t *testing.T) {
 		{
 			"{1: 2, 2: 3}",
 			map[object.HashKey]int64{
-				(&object.Integer{Value: 1}).HashKey(): 2,
-				(&object.Integer{Value: 2}).HashKey(): 3,
+				(object.Integer{Value: 1}).HashKey(): 2,
+				(object.Integer{Value: 2}).HashKey(): 3,
 			},
 		},
 		{
 			"{1 + 1: 2 * 2, 3 + 3: 4 * 4}",
 			map[object.HashKey]int64{
-				(&object.Integer{Value: 2}).HashKey(): 4,
-				(&object.Integer{Value: 6}).HashKey(): 16,
+				(object.Integer{Value: 2}).HashKey(): 4,
+				(object.Integer{Value: 6}).HashKey(): 16,
 			},
 		},
 	}
@@ -400,14 +400,14 @@ func TestHashMerging(t *testing.T) {
 		{
 			`{} + {"a": 1}`,
 			map[object.HashKey]int64{
-				(&object.String{Value: "a"}).HashKey(): 1,
+				(object.String{Value: "a"}).HashKey(): 1,
 			},
 		},
 		{
 			`{"a": 1} + {"b": 2}`,
 			map[object.HashKey]int64{
-				(&object.String{Value: "a"}).HashKey(): 1,
-				(&object.String{Value: "b"}).HashKey(): 2,
+				(object.String{Value: "a"}).HashKey(): 1,
+				(object.String{Value: "b"}).HashKey(): 2,
 			},
 		},
 	}