3 files changed, 129 insertions, 8 deletions
diff --git a/pkg/stack/min.go b/pkg/stack/min.go
new file mode 100644
index 0000000..e97aaed
--- /dev/null
+++ b/pkg/stack/min.go
@@ -0,0 +1,8 @@
+package stack
+
+func min(a, b int) int {
+	if a < b {
+		return a
+	}
+	return b
+}
diff --git a/pkg/stack/stack.go b/pkg/stack/stack.go
new file mode 100644
index 0000000..c307133
--- /dev/null
+++ b/pkg/stack/stack.go
@@ -0,0 +1,105 @@
+package stack
+
+type Stack struct {
+	size   int
+	height int
+	data   []int
+	next   *Stack // Pointer to the next element in the stack stack
+}
+
+func NewStack(size int, next *Stack) *Stack {
+	return &Stack{
+		size:   size,
+		height: 0,
+		data:   make([]int, size),
+		next:   next,
+	}
+}
+
+func (s *Stack) Clear() {
+	s.height = 0
+}
+
+func (s *Stack) Duplicate() {
+	if s.height > 0 {
+		s.Push(s.data[s.height-1])
+	} else {
+		s.Push(0)
+		s.Push(0)
+	}
+}
+
+func (s *Stack) Pop() int {
+	if s.height > 0 {
+		s.height--
+		return s.data[s.height]
+	}
+	return 0
+}
+
+func (s *Stack) Push(value int) {
+	if s.height >= s.size {
+		s.size += 32
+		s.data = append(s.data, make([]int, 32)...)
+	}
+	s.data[s.height] = value
+	s.height++
+}
+
+func (s *Stack) Swap() {
+	a := s.Pop()
+	b := s.Pop()
+	s.Push(a)
+	s.Push(b)
+}
+
+func (s Stack) GetHeights() []int {
+	if s.next != nil {
+		return append(s.next.GetHeights(), s.height)
+	} else {
+		return []int{s.height}
+	}
+}
+
+func (toss *Stack) Transfert(soss *Stack, n int) {
+	// Implements a value transfert between two stacks, intended for use with the '{'
+	// (aka begin) and '}' (aka end) stackstack commands
+	toss.height += n
+	if toss.height > toss.size {
+		toss.data = append(toss.data, make([]int, toss.height-toss.size)...)
+		toss.size = toss.height
+	}
+	for i := 1; i <= min(soss.height, n); i++ {
+		toss.data[toss.height-i] = soss.data[soss.height-i]
+		for i := min(soss.height, n) + 1; i <= n; i++ {
+			toss.data[toss.height-i] = 0
+		}
+	}
+	soss.height -= n
+	if soss.height < 0 {
+		soss.height = 0
+	}
+}
+
+func (s Stack) Next() *Stack {
+	return s.next
+}
+
+func (s *Stack) Discard(n int) {
+	// Implements a discard mechanism intended for use with the '}'(aka end) stackstack command
+	s.height -= n
+	if s.height < 0 {
+		s.height = 0
+	}
+}
+
+func (s *Stack) YCommandPick(n int, h int) {
+	if n > s.height {
+		s.height = 1
+		s.data[0] = 0
+	} else {
+		v := s.data[s.height-n]
+		s.height = h
+		s.Push(v)
+	}
+}
diff --git a/pkg/pointer/stack_test.go b/pkg/stack/stack_test.go
index 35700fd..2f15d3a 100644
--- a/pkg/pointer/stack_test.go
+++ b/pkg/stack/stack_test.go
@@ -1,4 +1,4 @@
-package pointer
+package stack
 
 import (
 	"testing"
@@ -7,15 +7,15 @@ import (
 )
 
 func TestClear(t *testing.T) {
-	s := NewStack()
+	s := NewStack(32, nil)
 	s.Clear()
 	require.Equal(t, 0, s.height)
 }
 
 func TestDupicate(t *testing.T) {
-	expected := NewStack()
+	expected := NewStack(32, nil)
 	expected.height = 2
-	s := NewStack()
+	s := NewStack(32, nil)
 	s.Duplicate()
 	require.Equal(t, expected.height, s.height)
 	s.Push(12)
@@ -27,7 +27,7 @@ func TestDupicate(t *testing.T) {
 }
 
 func TestPop(t *testing.T) {
-	s := NewStack()
+	s := NewStack(32, nil)
 	v := s.Pop()
 	require.Equal(t, 0, v)
 	s.Push(12)
@@ -41,7 +41,7 @@ func TestPop(t *testing.T) {
 }
 
 func TestPush(t *testing.T) {
-	s := NewStack()
+	s := NewStack(32, nil)
 	for i := 0; i < 32; i++ {
 		s.Push(i)
 	}
@@ -51,8 +51,8 @@ func TestPush(t *testing.T) {
 }
 
 func TestSwap(t *testing.T) {
-	s := NewStack()
-	s2 := NewStack()
+	s := NewStack(32, nil)
+	s2 := NewStack(32, nil)
 	s.Swap()
 	s2.Push(0)
 	s2.Push(0)
@@ -73,3 +73,11 @@ func TestSwap(t *testing.T) {
 	s.Swap()
 	require.Equal(t, s2, s)
 }
+
+func TestHeights(t *testing.T) {
+	// TODO
+}
+
+func TestTransfert(t *testing.T) {
+	// TODO
+}