define and call forge code

forge/builtins/builtins.go

@@ -6,7 +6,7 @@ type FE = forge.FE
 type XT = forge.XT
 
 type builtins struct {
-	Add, Lit XT
+	Add, Dup, Lit, Mult XT
 }
 
 func Get(f FE) *builtins {
@@ -25,6 +25,8 @@ func setup(f FE) *builtins {
 	}
 	return &builtins{
 		Add:  r("+", func(f FE, _ XT) { f.Push(f.Pop().(int) + f.Pop().(int)) }),
+		Dup:  r("dup", func(f FE, _ XT) { f.Push(f.Peek(0)) }),
 		Lit:  r("literal", func(f FE, _ XT) { f.Literal() }),
+		Mult: r("*", func(f FE, _ XT) { f.Push(f.Pop().(int) * f.Pop().(int)) }),
 	}
 }

forge/forge.go

@@ -92,10 +92,6 @@ func (it *xitem) Name() string {
 
 // forgeEnv methods
 
-func (f *forgeEnv) Voc() *fvoc {
-	return f.voc
-}
-
 func (f *forgeEnv) Code(items ...fitem) fptr {
 	code := newPtr(items...)
 	// ... pre-process (compile) code ...
@@ -112,6 +108,24 @@ func (f *forgeEnv) Call(code fptr) {
 	f.ip = f.rs.Pop().(fptr)
 }
 
+func (f *forgeEnv) Exec(items ...fitem) {
+	f.Call(f.Code(items...))
+}
+
+func (f *forgeEnv) Def(name string, items ...fitem) XT {
+	xt := Register(f.voc, name, callDef)
+	xt.Body().Append(f.Code(items...))
+	return xt
+}
+
+func (f *forgeEnv) Literal() {
+	f.Push(f.ip.Next().Value())
+}
+
+func (f *forgeEnv) Voc() *fvoc {
+	return f.voc
+}
+
 func (f *forgeEnv) Push(it fitem) {
 	f.ds.Push(it)
 }
@@ -120,6 +134,12 @@ func (f *forgeEnv) Pop() fitem {
 	return f.ds.Pop()
 }
 
-func (f *forgeEnv) Literal() {
+func (f *forgeEnv) Peek(d int) fitem {
-	f.Push(f.ip.Next().Value())
+	return f.ds.Peek(d)
+}
+
+// basic functions for executable items
+
+func callDef(f *forgeEnv, xt XT) {
+	f.Call(xt.Body().Value().(fptr))
 }

tests/forge_test.go

@@ -16,6 +16,10 @@ func TestForge(tb *tbase.T) {
 func ExecTest(t *testing.T) {
 	fe := forge.NewFE()
 	b := builtins.Get(fe)
-	fe.Call(fe.Code(b.Lit, 4, b.Lit, 2, b.Add))
+	c1 := fe.Code(b.Lit, 4, b.Lit, 2, b.Add)
+	fe.Call(c1)
 	t.AssertEqual(fe.Pop(), 6)
+	sq := fe.Def("square", b.Dup, b.Mult)
+	fe.Exec(b.Lit, 3, sq, b.Lit, 2, b.Add)
+	t.AssertEqual(fe.Pop(), 11)
 }