multiwayif.hs

newtype Branch (o :: OS) e m a = Branch (ExceptT e m a)                                                                                        
  deriving                                                                                                                                     
    ( Applicative, Eq, Foldable, Functor, Monad, Traversable                                                                                   
    )                                                                                                                                          
                                                                                                                                               
branchToExceptT :: Branch o e m a -> ExceptT e m a                                                                                             
branchToExceptT = coerce                                                                                                                       
                                                                                                                                               
data Branches e m a = Branches                                                                                                                 
  { _branchPulseSecure  :: Branch 'PulseSecure  e m a                                                                                          
  , _branchJUNOS        :: Branch 'JUNOS        e m a                                                                                          
  , _branchPaloAlto     :: Branch 'PaloAlto     e m a                                                                                          
  , _branchArubaOS      :: Branch 'ArubaOS      e m a                                                                                          
  , _branchAvayaNortel  :: Branch 'AvayaNortel  e m a                                                                                          
  , _branchAvayaERS     :: Branch 'AvayaERS     e m a                                                                                          
  , _branchAvayaVSP9000 :: Branch 'AvayaVSP9000 e m a                                                                                          
  , _branchBrocadeVDX   :: Branch 'BrocadeVDX   e m a                                                                                          
  , _branchBrocadeMLX   :: Branch 'BrocadeMLX   e m a                                                                                          
  , _branchBrocadeICX   :: Branch 'BrocadeICX   e m a                                                                                          
  , _branchBrocadeCER   :: Branch 'BrocadeCER   e m a                                                                                          
  , _branchCisco        :: Branch 'Cisco        e m a                                                                                          
  , _branchF5           :: Branch 'F5           e m a                                                                                          
  , _branchUnrecognised :: Branch 'Unrecognised e m a                                                                                          
  }                                                                                                                                            
                                                                                                                                               
branch :: (Monad m)                                                                                                                            
  => ([a] -> b)                                                                                                                                
  -> Branches e m a                                                                                                                            
  -> ExceptT e m b                                                                                                                             
branch fun br = do                                                                                                                             
  let a = branchToExceptT (_branchPulseSecure  br)                                                                                             
  let b = branchToExceptT (_branchJUNOS        br)                                                                                             
  let c = branchToExceptT (_branchPaloAlto     br)                                                                                             
  let d = branchToExceptT (_branchArubaOS      br)                                                                                             
  let e = branchToExceptT (_branchAvayaNortel  br)
  let f = branchToExceptT (_branchAvayaERS     br)                                                                                             
  let g = branchToExceptT (_branchAvayaVSP9000 br)                                                                                             
  let h = branchToExceptT (_branchBrocadeVDX   br)                                                                                             
  let i = branchToExceptT (_branchBrocadeMLX   br)                                                                                             
  let j = branchToExceptT (_branchBrocadeICX   br)                                                                                             
  let k = branchToExceptT (_branchBrocadeCER   br)                                                                                             
  let l = branchToExceptT (_branchCisco        br)                                                                                             
  let m = branchToExceptT (_branchF5           br)                                                                                             
  let n = branchToExceptT (_branchUnrecognised br)                                                                                             
                                                                                                                                               
  a' <- a; b' <- b; c' <- c; d' <- d; e' <- e;                                                                                                 
  f' <- f; g' <- g; h' <- h; i' <- i; j' <- j;                                                                                                 
  k' <- k; l' <- l; m' <- m; n' <- n;                                                                                                          
                                                                                                                                               
  let res = fun [a', b', c', d', e', f', g', h', i', j', k', l', m', n']                                                                       
  pure res