Simplify (data-ify) command arguments

src/Dodge/Event.hs

@@ -38,7 +38,8 @@ import Data.Maybe
 --import Data.Char
 --import Data.List
 --import Data.Function (on)
-import qualified Data.Set             as S
+import qualified Data.Map.Strict as M
+import qualified Data.Set as S
 import qualified Data.Text as T
 import SDL
 
@@ -157,14 +158,14 @@ wheelEvent y w = case _hudElement $ _hud w of
                 & tmInput . tiText %~ replacewith tm newi
     updatetermsubsel tm = case tm ^? tmInput . tiSel of
         Nothing -> tm
-        Just (i,j) -> let newj = (j - yi) `mod` (1 + length (_tcArguments (scrollCommands tm !! i) tm w))
+        Just (i,j) -> let newj = (j - yi) `mod` (1 + length (getArguments (scrollCommands tm !! i) tm w))
             in tm & tmInput . tiSel .~ (i,newj)
                 & tmInput . tiText %~ replacewith' tm i newj w
     replacewith tp newi _ = T.pack (_tcString (scrollCommands tp !! newi))
     replacewith' tp i j w' _ = T.pack $ _tcString tc ++ " " ++ arg-- ++ ((_tcArguments tp) w !! j)
       where
         arg :: String
-        arg = ("": _tcArguments tc tp w' )!! j
+        arg = ("": getArguments tc tp w' )!! j
         tc = scrollCommands tp !! i
     numcombs = length $ combineItemListYou w
     yi = round $ signum y
@@ -173,6 +174,11 @@ wheelEvent y w = case _hudElement $ _hud w of
     lbDown = ButtonLeft `S.member` _mouseButtons w
     invKeyDown = ScancodeCapsLock `S.member` _keys w
 
+getArguments :: TerminalCommand -> Terminal -> World -> [String]
+getArguments tc tm w = case _tcEffect tc tm w of
+    NoArguments {} -> []
+    OneArgument _ m -> M.keys m
+
 scrollCommands :: Terminal -> [TerminalCommand]
 scrollCommands = (nullCommand :) . _tmScrollCommands
 nullCommand :: TerminalCommand
@@ -180,9 +186,7 @@ nullCommand = TerminalCommand
     { _tcString = ""
     , _tcAlias  = []
     , _tcHelp   = ""
-    , _tcArgumentType = Nothing
-    , _tcArguments  = const (const [])
-    , _tcEffect = \_ _ _ -> Right []
+    , _tcEffect = \_ _ -> NoArguments []
     }
 
 scrollRBOption :: Float -> World -> World