standart IO()
standart IO() in function (do-notation)
function return -> send answer, not stop process
function return - show non stop
throw exeption on top
catch throwing exception
change catch function to handle function
use try function / try :: Exception e => IO a -> IO (Either e a)
use try function when 2 divide 0 (need wrap evaluate because IO-waiting)
throw own exception! ERRORgit add --allgit add --all! page 124 New Branch
Manad - IO - sequentially composition (>>=) :: IO a -> (a -> IO b) -> IO b
Manad - IO - then (>>) :: IO a -> IO b -> IO b
Manad - IO - try IO example without do notation - Result is great