strategy.hs

data Parser = WebParser | DbParser

class ParseStrategy p where
  parse :: p -> String -> String

instance ParseStrategy Parser where
  parse WebParser s = "code for parsing web stuff goes here"
  parse DbParser s = "code for parsing db stuff goes here"

fromDB = parse DbParser
fromWeb = parse WebParser

main :: IO ()
main = do
  -- decide which parser to utilize
  let s = fromDB "asdf"
  putStrLn s