generated at
either
LeftとRightの値を処理する関数を渡してEitherを取り除く

hs
either :: (e -> c) -> (a -> c) -> Either e a -> c


例
hs
import Data.Either test = either (+ 1) (* 2) main = do print $ test (Left 4) -- 5 print $ test (Right 4) -- 8