Continued implementing the Instruction Pointer

4 files changed, 54 insertions, 3 deletions

diff --git a/pkg/pointer/pointer.go b/pkg/pointer/pointer.go
index 5b4b860..8f2a299 100644
--- a/pkg/pointer/pointer.go
+++ b/pkg/pointer/pointer.go
@@ -6,13 +6,16 @@ type Pointer struct {
 	x     int
 	y     int
 	delta *Delta
+	// The Storage offset
+	sox int
+	soy int
 }
 
 func NewPointer() *Pointer {
 	return &Pointer{delta: NewDelta(1, 0)}
 }
 
-func (p Pointer) ForkPointer() *Pointer {
+func (p Pointer) Split() *Pointer {
 	return &p // p is already a copy
 }
 
diff --git a/pkg/pointer/pointer_test.go b/pkg/pointer/pointer_test.go
index 3a77507..b6a3898 100644
--- a/pkg/pointer/pointer_test.go
+++ b/pkg/pointer/pointer_test.go
@@ -12,14 +12,14 @@ func TestNewPointer(t *testing.T) {
 	require.Equal(t, NewPointer(), &Pointer{delta: &Delta{1, 0}})
 }
 
-func TestForkPointer(t *testing.T) {
+func TestSplit(t *testing.T) {
 	file, err := os.Open("../field/test_data/hello.b98")
 	require.NoError(t, err, "Failed to open file")
 	defer file.Close()
 	f, err := field.Load(file)
 	require.NoError(t, err)
 	p := NewPointer()
-	p2 := p.ForkPointer()
+	p2 := p.Split()
 	// We check that p2 is a real copy
 	p.Step(*f)
 	p2.Step(*f)
diff --git a/pkg/pointer/storage-offset.go b/pkg/pointer/storage-offset.go
new file mode 100644
index 0000000..0fcd9ed
--- /dev/null
+++ b/pkg/pointer/storage-offset.go
@@ -0,0 +1,13 @@
+package pointer
+
+func (p Pointer) GetStorageOffset() (x, y int) {
+	return p.sox, p.soy
+}
+
+func (p *Pointer) CalculateNewStorageOffset() {
+	p.sox, p.soy = p.x+p.delta.x, p.y+p.delta.y
+}
+
+func (p *Pointer) SetStorageOffset(x, y int) {
+	p.sox, p.soy = x, y
+}
diff --git a/pkg/pointer/storage-offset_test.go b/pkg/pointer/storage-offset_test.go
new file mode 100644
index 0000000..26a5f38
--- /dev/null
+++ b/pkg/pointer/storage-offset_test.go
@@ -0,0 +1,35 @@
+package pointer
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestGetStorageOffset(t *testing.T) {
+	p := NewPointer()
+	x, y := p.GetStorageOffset()
+	require.Equal(t, x, 0)
+	require.Equal(t, y, 0)
+	p.SetStorageOffset(3, 8)
+	x, y = p.GetStorageOffset()
+	require.Equal(t, x, 3)
+	require.Equal(t, y, 8)
+}
+
+func TestCalculateNewStorageOffset(t *testing.T) {
+	p := NewPointer()
+	p.CalculateNewStorageOffset()
+	x, y := p.GetStorageOffset()
+	require.Equal(t, x, 1)
+	require.Equal(t, y, 0)
+	p.sox, p.soy = 3, 2
+	x, y = p.GetStorageOffset()
+	require.Equal(t, x, 3)
+	require.Equal(t, y, 2)
+	p.x, p.y = 8, 12
+	p.CalculateNewStorageOffset()
+	x, y = p.GetStorageOffset()
+	require.Equal(t, x, 9)
+	require.Equal(t, y, 12)
+}