= case reads str of
((x,_):_) -> x -- Be forgiving: ignore trailing goop, and alternative parses
[] -> ghcError (UsageError ("Malformed argument " ++ str ++ " for flag " ++ sw))
= case reads str of
((x,_):_) -> x -- Be forgiving: ignore trailing goop, and alternative parses
[] -> ghcError (UsageError ("Malformed argument " ++ str ++ " for flag " ++ sw))