forge: control words: factorial ok, with if, leave, repeat

forge/builtins/builtins.go

@@ -1,6 +1,8 @@
 package builtins
 
 import (
+	"fmt"
+
 	"git.sr.ht/~cco/go-scopes/forge"
 )
 
@@ -9,7 +11,7 @@ type XT = forge.XT
 type FPtr = forge.FPtr
 
 type builtins struct {
-	Add, Body, Code, Comp, Drop, Dup, Get, If, IfElse, Leave, LT, Lit,
+	Add, Body, Code, Comp, Do, Dot, Drop, Dup, Get, If, IfElse, Leave, LT, Lit,
 	Mult, New1, Over, Put, Reg, Repeat, Sub, Swap,
 	Var1 XT
 }
@@ -33,6 +35,8 @@ func setup(f FE) *builtins {
 		Body:   r("body", func(f FE, _ XT) { f.Push(f.Pop().(XT).Code().New().Next()) }),
 		Code:   r("code", func(f FE, _ XT) { f.Push(f.Code()) }),
 		Comp:   r("comp", func(f FE, _ XT) { f.LatestXT().Code().Append(f.Pop()) }),
+		Do:     r("do", func(f FE, _ XT) { f.Call(f.Literal().(FPtr)) }),
+		Dot:    r(".", func(f FE, _ XT) { fmt.Println(f.Peek(0)) }),
 		Drop:   r("drop", func(f FE, _ XT) { f.Pop() }),
 		Dup:    r("dup", func(f FE, _ XT) { f.Push(f.Peek(0)) }),
 		Get:    r("@", func(f FE, _ XT) { f.Push(f.Pop().(FPtr).Value()) }),

forge/forge.go

@@ -105,7 +105,10 @@ func (f *forgeEnv) Peek(d int) fitem {
 }
 
 func (f *forgeEnv) RPop() fptr {
-	return f.rs.Pop().(fptr)
+	if f.rs.Depth() > 0 {
+		return f.rs.Pop().(fptr)
+	}
+	return f.Code()
 }
 
 func (f *forgeEnv) Reset() fptr {

tests/forge_test.go

@@ -47,13 +47,15 @@ func CoreTest(t *testing.T) {
 
 func ControlTest(t *testing.T) {
 	fac := fe.Exec(fe.Code(
-		b.Dup, fe.Code(
+		b.Dup, b.Do, fe.Code(
 			b.Dup, 3, b.LT, b.If, fe.Code(
 				b.Drop, b.Leave),
-			b.Swap, b.Over, b.Mult, b.Swap, 1, b.Sub, b.Repeat)),
+			1, b.Sub, b.Swap, b.Over, b.Mult, b.Swap, b.Repeat)),
 		"fac", b.Reg).LatestXT()
-	fe.Exec(2, fac)
-	//t.AssertEqual(fe.Pop(), 12)
+	t.AssertEqual(fe.Exec(1, fac).Pop(), 1)
+	t.AssertEqual(fe.Exec(2, fac).Pop(), 2)
+	t.AssertEqual(fe.Exec(3, fac).Pop(), 6)
+	t.AssertEqual(fe.Exec(4, fac).Pop(), 24)
 }
 
 func RepTest(t *testing.T) {