Implementations of a function that converts a String to an Action

ConvertStringToAction.hs

convertStringToAction :: String -> Action
convertStringToAction str = case str of
  "Look"    -> Look
  "New"     -> New
  otherwise -> Quit

-- guards (охранные выражения)
convertStringToAction' :: String -> Action
convertStringToAction' str | str == "Look" = Look
                           | str == "New"  = New
                           | otherwise     = Quit
 
-- pattern matching (сопоставление с образцом)
convertStringToAction'' :: String -> Action
convertStringToAction'' "Look" = Look
convertStringToAction'' "New"  = New
convertStringToAction'' _      = Quit