make XT an interface, allowing different implementations

forge/forge.go

@@ -45,15 +45,42 @@ var newVoc = voc.NewVoc[fitem]
 var newScalar = ptr.NewScalar[fitem]
 var newPtr = ptr.NewSlice[fitem]
 
+// new XT ...
+
+type XT interface {
+	Name() string
+	Fct() Callable
+	Code() fptr
+	Data() fptr
+}
+
 // xitem (executable item) / XT (execution token)
 
 type xitem struct {
 	name string
 	fct  Callable
 	body fptr
+	code fptr
+	data fptr
 }
 
-type XT = *xitem
+func (it *xitem) Name() string {
+	return it.name
+}
+
+func (it *xitem) Fct() Callable {
+	return it.fct
+}
+
+func (it *xitem) Code() fptr {
+	//return it.code
+	return it.body
+}
+
+func (it *xitem) Data() fptr {
+	//return it.data
+	return it.body
+}
 
 func Register(voc *fvoc, name string, fct Callable) *xitem {
 	it := xitem{
@@ -64,10 +91,6 @@ func Register(voc *fvoc, name string, fct Callable) *xitem {
 	return &it
 }
 
-func (it *xitem) Name() string {
-	return it.name
-}
-
 // forgeEnv methods
 
 func (f *forgeEnv) Code(items ...fitem) fptr {
@@ -81,7 +104,7 @@ func (f *forgeEnv) Call(code fptr) {
 	f.ip = code.Clone()
 	for f.ip.Next() != nil {
 		xt := f.ip.Value().(XT)
-		xt.fct(f, xt)
+		xt.Fct()(f, xt)
 	}
 	f.ip = f.rs.Pop().(fptr)
 }
@@ -126,9 +149,9 @@ func (f *forgeEnv) Peek(d int) fitem {
 // basic functions for executable items
 
 func doDef(f *forgeEnv, xt XT) {
-	f.Call(xt.body.Value().(fptr))
+	f.Call(xt.Code().Value().(fptr))
 }
 
 func doData(f *forgeEnv, xt XT) {
-	f.Push(xt.body.Value())
+	f.Push(xt.Data().Value())
 }