import action for out of scope names, start introducing error types

src/Lib/Elab.newt

@@ -1535,9 +1535,6 @@ infer ctx tm@(RUpdateRec fc _ _) = error fc "I can't infer record updates"
 
 infer ctx (RVar fc nm) = go 0 ctx.types
   where
-    entryNS : TopEntry → String
-    entryNS (MkEntry fc (QN ns _) _ _ _) = ns
-
     go : Int -> List (String × Val)  -> M (Tm × Val)
     go i Nil = do
       top <- getTop
@@ -1546,13 +1543,8 @@ infer ctx (RVar fc nm) = go 0 ctx.types
           debug $ \ _ => "lookup \{show name} as \{show def}"
           vty <- eval Nil ty
           pure (Ref fc name, vty)
-        Nothing => do
-          let mods = map entryNS $ lookupAll nm top
-          let extra = case mods of
-            Nil => ""
-            -- For the benefit of the editor, but only sees transitive modules
-            _ => ", try importing: \{joinBy ", " mods}"
-          error fc "\{show nm} not in scope\{extra}"
+        -- Can we soften this without introducing a meta?
+        Nothing => throwError $ ENotFound fc nm
     go i ((x, ty) :: xs) = if x == nm then pure (Bnd fc i, ty)
       else go (i + 1) xs