i

diff --git a/implementations/Elm/src/Joy.elm b/implementations/Elm/src/Joy.elm
index 41982f0..e355054 100644 (file)
--- a/implementations/Elm/src/Joy.elm
+++ b/implementations/Elm/src/Joy.elm
@@ -34,6 +34,7 @@ joy stack expression =
 joy_eval : String -> JList -> JList -> Result String (JList, JList)
 joy_eval symbol stack expression =
     case symbol of
+        "i" -> joy_i stack expression
         "+" -> joy_binary_math_op (+) stack expression
         "-" -> joy_binary_math_op (-) stack expression
         "*" -> joy_binary_math_op (*) stack expression
@@ -56,6 +57,13 @@ joy_eval symbol stack expression =
         _ -> Err ("Unknown word: " ++ symbol)
 
 
+joy_i : JList -> JList -> Result String (JList, JList)
+joy_i stack expression =
+    case pop_list(stack) of
+        Ok (a, s0) -> Ok (s0, a ++ expression)
+        Err msg -> Err msg
+
+
 joy_binary_math_op : (Int -> Int -> Int) -> JList -> JList -> Result String (JList, JList)
 joy_binary_math_op op stack expression =
     case pop_int(stack) of