applicative - In Haskell, is there an abstraction for the <?>-operator? -

i found myself writing code:

import control.applicative ((<|>))  x = ma <|> mb <?> c  (<?>) :: maybe -> -> x  <?> _ = x nothing <?> y = y 

where ma :: maybe a, mb :: maybe a, c :: a, , x :: a. basically, code says: pick first alternative not empty , default c. can call "reverse maybe monad" analogy <?> pure.

equivalently, have written

just x = ma <|> mb <|> pure c, 

but feel uncomfortable irrefutable pattern. or, of course,

x = frommaybe c (ma <|> mb) 

because frommaybe === flip <?>.

the <?> operator inspired parsec. suspicious when find myself defining utility functions that, couldn't find defaulting behavior anywhere.

apparently alternative , applicative not powerful enough.

did miss type-class?

i think it's idea leave things @ (<?>) = flip frommaybe.

if you'd generalize though, foldable seems simplest class notion of emptiness:

(<?>) :: foldable t => t -> -> ta <?> = foldr const ta  

this returns a if ta empty or else first element of ta. examples:

just 0 <?> 10 == 0 nothing <?> 0 == 0 [] <?> 10 == 10