1 files changed, 74 insertions, 0 deletions
diff --git a/vm/type.go b/vm/type.go
new file mode 100644
index 0000000..d29de48
--- /dev/null
+++ b/vm/type.go
@@ -0,0 +1,74 @@
+package vm
+
+import "reflect"
+
+// Runtime type and value representations (based on reflect).
+
+// Type is the representation of a runtime type.
+type Type struct {
+	Name  string
+	Rtype reflect.Type
+}
+
+func (t *Type) Elem() *Type {
+	return &Type{Rtype: t.Rtype.Elem()}
+}
+
+func (t *Type) Out(i int) *Type {
+	return &Type{Rtype: t.Rtype.Out(i)}
+}
+
+// Value is the representation of a runtime value.
+type Value struct {
+	Type *Type
+	Data reflect.Value
+}
+
+// NewValue returns an addressable zero value for the specified type.
+func NewValue(typ *Type) Value {
+	return Value{Type: typ, Data: reflect.New(typ.Rtype).Elem()}
+}
+
+// TypeOf returns the runtime type of v.
+func TypeOf(v any) *Type {
+	t := reflect.TypeOf(v)
+	return &Type{Name: t.Name(), Rtype: t}
+}
+
+// ValueOf returns the runtime value of v.
+func ValueOf(v any) Value {
+	return Value{Data: reflect.ValueOf(v)}
+}
+
+func PointerTo(t *Type) *Type {
+	return &Type{Rtype: reflect.PointerTo(t.Rtype)}
+}
+
+func ArrayOf(size int, t *Type) *Type {
+	return &Type{Rtype: reflect.ArrayOf(size, t.Rtype)}
+}
+
+func SliceOf(t *Type) *Type {
+	return &Type{Rtype: reflect.SliceOf(t.Rtype)}
+}
+
+func FuncOf(arg, ret []*Type, variadic bool) *Type {
+	a := make([]reflect.Type, len(arg))
+	for i, e := range arg {
+		a[i] = e.Rtype
+	}
+	r := make([]reflect.Type, len(ret))
+	for i, e := range ret {
+		r[i] = e.Rtype
+	}
+	return &Type{Rtype: reflect.FuncOf(a, r, variadic)}
+}
+
+func StructOf(fields []*Type) *Type {
+	rf := make([]reflect.StructField, len(fields))
+	for i, f := range fields {
+		rf[i].Name = "X" + f.Name
+		rf[i].Type = f.Rtype
+	}
+	return &Type{Rtype: reflect.StructOf(rf)}
+}