From 91322dae3a2d13a30d2196ad5c1dd6b055c6aed3 Mon Sep 17 00:00:00 2001
From: Helmut Merz <helmutm@cy55.de>
Date: Fri, 21 Jul 2023 19:47:57 +0200
Subject: [PATCH] forge: Exec() basically working

---
 common/ptr/slice.go        |  9 ++++---
 forge/builtins/builtins.go | 23 ++++++++++++++++
 forge/forge.go             | 55 ++++++++++++++++++++++++++++++++++++--
 tests/forge_test.go        |  7 ++++-
 4 files changed, 87 insertions(+), 7 deletions(-)
 create mode 100644 forge/builtins/builtins.go

diff --git a/common/ptr/slice.go b/common/ptr/slice.go
index 1b2ff25..d8b5577 100644
--- a/common/ptr/slice.go
+++ b/common/ptr/slice.go
@@ -9,13 +9,14 @@ type sptr[V any] struct {
 	offset int
 }
 
-func newSliceSeq[V any]() *sliceseq[V] {
-	return &sliceseq[V]{}
+func newSliceSeq[V any](s ...V) *sliceseq[V] {
+	seq := sliceseq[V](s)
+	return &seq
 }
 
-func NewSlice[V any]() *sptr[V] {
+func NewSlice[V any](s ...V) *sptr[V] {
 	return &sptr[V]{
-		seq:    newSliceSeq[V](),
+		seq:    newSliceSeq[V](s...),
 		offset: -1,
 	}
 }
diff --git a/forge/builtins/builtins.go b/forge/builtins/builtins.go
new file mode 100644
index 0000000..534c48d
--- /dev/null
+++ b/forge/builtins/builtins.go
@@ -0,0 +1,23 @@
+package builtins
+
+import "git.sr.ht/~cco/go-scopes/forge"
+
+type FE = *forge.ForgeEnv
+type XT = *forge.Item
+
+type builtins struct {
+	Add, Lit forge.XT
+}
+
+func Setup(f FE) *builtins {
+	r := func(name string, fct forge.Callable) XT {
+		return forge.Register(f.Voc(), name, fct)
+	}
+	return &builtins{
+		Lit: r("literal", literal),
+	}
+}
+
+func literal(f FE, it XT) {
+	f.Push(f.IP().Next().Value())
+}
diff --git a/forge/forge.go b/forge/forge.go
index 016f4a1..013a96c 100644
--- a/forge/forge.go
+++ b/forge/forge.go
@@ -16,7 +16,7 @@ type Ptr = ptr.Ptr[DataItem]
 type Stack = stack.Stack[DataItem]
 type Voc = voc.Vocabulary[XT]
 
-type Callable func(*ForgeEnv, *Item)
+type Callable func(*ForgeEnv, XT)
 
 type Item struct {
 	name      string
@@ -58,9 +58,60 @@ func newFE(voc *Voc) *ForgeEnv {
 	}
 }
 
+// basic functions and methods
+
+func Register(voc *Voc, name string, fct Callable) *Item {
+	it := Item{
+		name: name,
+		fct:  fct,
+	}
+	voc.Register(name, &it)
+	return &it
+}
+
+func (it *Item) IsImmediate() bool {
+	return it.immediate
+}
+
+func (it *Item) Immediate() {
+	it.immediate = true
+}
+
+func (it *Item) Body() Ptr {
+	if it.body == nil {
+		it.body = ptr.NewSlice[DataItem]()
+	}
+	return it.body
+}
+
+func (it *Item) Name() string {
+	return it.name
+}
+
 // ForgeEnv methods
 
-func (f *ForgeEnv) Exec() {
+func (f *ForgeEnv) Voc() *Voc {
+	return f.voc
+}
+
+func (f *ForgeEnv) IP() Ptr {
+	return f.ip
+}
+
+func (f *ForgeEnv) Exec(items ...DataItem) {
+	f.ip = ptr.NewSlice[DataItem](items...)
+	for f.ip.Next() != nil {
+		it := f.ip.Value().(XT)
+		it.fct(f, it)
+	}
+}
+
+func (f *ForgeEnv) Push(it DataItem) {
+	f.ds.Push(it)
+}
+
+func (f *ForgeEnv) Pop() DataItem {
+	return f.ds.Pop()
 }
 
 // dummy stuff for testing
diff --git a/tests/forge_test.go b/tests/forge_test.go
index 0bf359e..d3996fe 100644
--- a/tests/forge_test.go
+++ b/tests/forge_test.go
@@ -5,6 +5,7 @@ import (
 
 	"git.sr.ht/~cco/go-scopes/common/testing"
 	"git.sr.ht/~cco/go-scopes/forge"
+	"git.sr.ht/~cco/go-scopes/forge/builtins"
 )
 
 func TestForge(tb *tbase.T) {
@@ -14,5 +15,9 @@ func TestForge(tb *tbase.T) {
 
 func ExecTest(t *testing.T) {
 	fe := forge.NewFE()
-	fe.Exec()
+	b := builtins.Setup(fe)
+	fe.Exec(b.Lit, 4)
+	t.AssertEqual(fe.Pop(), 4)
+	// fe.Execute(forge.Code{b.Lit, 3, b.Lit, 2, b.Add})
+	// t.AssertEqual(fe.Pop(), 5)
 }