6 files changed, 90 insertions, 2 deletions
diff --git a/src/field.nim b/src/field.nim
index a9d706e..0a741c9 100644
--- a/src/field.nim
+++ b/src/field.nim
@@ -213,3 +213,6 @@ func Step*(f: Field, v: tuple[x, y: int], d: tuple[x, y: int]): (int, int) =
     if not f.IsIn(x2, y2):
       return (x, y)
     x = x2; y = y2
+
+func GetSize*(f: Field): (int, int, int, int) =
+  return (f.x, f.y, f.lx, f.ly)
diff --git a/src/stack.nim b/src/stack.nim
index f08baf0..4565b5c 100644
--- a/src/stack.nim
+++ b/src/stack.nim
@@ -80,3 +80,19 @@ func Discard*(s: var Stack, n: int) =
 
 func Next*(s: Stack): ref Stack =
   return s.next
+
+func GetHeights*(s: Stack): seq[int] =
+  if s.next != nil:
+    result = s.next[].GetHeights()
+    result.add(s.height)
+  else:
+    return @[s.height]
+
+func YCommandPick*(s: var Stack, n, h: int) =
+  if n > s.height:
+    s.height = 1
+    s.data[0] = 0
+  else:
+    let v = s.data[s.height-n]
+    s.height = h
+    s.Push(v)
diff --git a/src/stackStack.nim b/src/stackStack.nim
index d55d5d9..b2bf29f 100644
--- a/src/stackStack.nim
+++ b/src/stackStack.nim
@@ -52,8 +52,7 @@ func End*(ss: var StackStack, v: var tuple[x, y: int]): bool =
   let toss = ss.head
   let soss = toss[].Next()
   let n = toss[].Pop()
-  v.y = soss[].Pop()
-  v.x = soss[].Pop()
+  (v.x, v.y) = soss[].PopVector()
   if n > 0:
     soss[].Transfert(toss[], n)
   else:
@@ -61,3 +60,22 @@ func End*(ss: var StackStack, v: var tuple[x, y: int]): bool =
   dec ss.height
   ss.head = soss
   return false
+
+func Under*(ss: var StackStack): bool =
+  if ss.height == 1:
+    return true
+  let soss = ss.head[].Next()
+  let n = ss.Pop()
+  if n > 0:
+    for i in 0..<n:
+      ss.Push(soss[].Pop())
+  else:
+    for i in 0 ..< -n:
+      soss[].Push(ss.Pop())
+  return false
+
+func GetHeights*(ss: StackStack): (int, seq[int]) =
+  return (ss.height, ss.head[].GetHeights)
+
+func YCommandPick*(ss: var StackStack, n, h: int) =
+  ss.head[].YCommandPick(n, h)
diff --git a/tests/field.nim b/tests/field.nim
index e60887a..455d81f 100644
--- a/tests/field.nim
+++ b/tests/field.nim
@@ -216,3 +216,12 @@ suite "Field":
     check dna[].Step((1, 2), (3, 5)) == (4, 7)
     check dna[].Step((6, 1), (1, 1)) == (5, 0)
     check dna[].Step((1, 4), (-2, 2)) == (5, 0)
+  test "GetSize":
+    var minimal = Load("examples/minimal.b98")
+    var hello = Load("examples/hello.b98")
+    var hello2 = Load("examples/hello2.b98")
+    var dna = Load("examples/dna.b98")
+    check minimal[].GetSize() == (0, 0, 1, 1)
+    check hello[].GetSize() == (0, 0, 24, 1)
+    check hello2[].GetSize() == (1, 0, 33, 2)
+    check dna[].GetSize() == (0, 0, 7, 8)
diff --git a/tests/stack.nim b/tests/stack.nim
index cecdef9..ebbbe5d 100644
--- a/tests/stack.nim
+++ b/tests/stack.nim
@@ -144,3 +144,6 @@ suite "Stack":
     check empty[].Next() == nil
     var some = NewStack(next = empty)
     check some[].Next() == empty
+  test "GetHeights":
+    var empty = NewStack()
+    check empty[].GetHeights == @[0]
diff --git a/tests/stackStack.nim b/tests/stackStack.nim
index 5451d79..8ff3e62 100644
--- a/tests/stackStack.nim
+++ b/tests/stackStack.nim
@@ -110,3 +110,42 @@ suite "StackStack":
     check empty.height == 1
     check empty[].Pop() == 1
     check empty[].Pop() == 0
+  test "Under":
+    var empty = NewStackStack()
+    empty[].Push(18)
+    check empty[].Under() == true
+    check empty[].Pop() == 18
+    empty[].Push(1)
+    empty[].Push(2)
+    empty[].Push(3)
+    empty[].Push(4)
+    empty[].Push(5)
+    empty[].Push(6)
+    empty[].Push(0)
+    empty[].Begin((7, 8))
+    empty[].Push(9)
+    empty[].Push(0)
+    check empty[].Under() == false
+    check empty[].Pop() == 9
+    empty[].Push(9)
+    empty[].Push(2)
+    check empty[].Under() == false
+    check empty[].Pop() == 7
+    check empty[].Pop() == 8
+    check empty[].Pop() == 9
+    empty[].Push(9)
+    empty[].Push(10)
+    empty[].Push(-3)
+    check empty[].Under() == false
+    check empty[].Pop() == 0
+    check empty[].Pop() == 0
+    check empty[].Pop() == 0
+    var v: tuple[x, y: int]
+    check empty[].End(v) == false
+    check v.x == 9
+    check v.y == 0
+    check empty[].Pop() == 10
+    check empty[].Pop() == 6
+  test "GetHeights":
+    var empty = NewStackStack()
+    check empty[].GetHeights == (1, @[0])