- Just container
- = Error ("Cannot lock new container, craner contains " + container)
-eval (Unlock b1 b2) s =case s.locked of
- Just container | s.craneOnQuay
- = Result {s & onQuay = [container:s.onQuay], locked = Nothing}
- = Result {s & onShip = [container:s.onShip], locked = Nothing}
- Nothing = Error "Cannot unlock container, craner contains nothing"
- Wait bm = Result s
- a :. b = eval b (eval a r)
- WhileContainerBelow bm action
- | s.craneOnQuay && not (isEmpty s.onQuay) ||
- not s.craneOnQuay && not (isEmpty s.onShip)
- = eval (action :. WhileContainerBelow bm action) r
- = r
-*/
+eval (Lock _ _) s=:{locked=(Just c)}
+ = Error ("Cannot lock new container, craner contains " +++ c)
+eval (Unlock _ _) s=:{locked=(Just c)}
+ | s.craneOnQuay = pure {s & onQuay = [c:s.onQuay], locked = Nothing}
+ = pure {s & onShip = [c:s.onShip], locked = Nothing}
+eval (Unlock b1 b2) s=:{locked=Nothing}
+ = Error "Cannot unlock container, crane contains nothing"
+eval (Wait _) s = Ok s
+eval (a :. b) s = eval a s >>= eval b
+eval (WhileContainerBelow _ action) s
+ | s.craneOnQuay && not (isEmpty s.onQuay) || not s.craneOnQuay && not (isEmpty s.onShip)
+ = eval (action :. whileContainerBelow action) s
+ = pure s