never executed always true always false

    1 module HelVM.HelIO.Containers.LLInsertDef where
    2 
    3 import           Data.Default
    4 import           Data.Sequence ((|>))
    5 
    6 import qualified Data.IntMap   as IntMap
    7 import qualified Data.Sequence as Seq
    8 
    9 -- | Insert a new element
   10 naturalInsertDef :: InsertDef full item => Natural -> item -> full -> full
   11 naturalInsertDef = insertDef <$> fromIntegral
   12 
   13 -- | Type Class
   14 class InsertDef full item | full -> item where
   15   insertDef :: Int -> item -> full -> full
   16 
   17 instance Default a => InsertDef [a] a where
   18   insertDef 0 e []     = [e]
   19   insertDef 0 e (_:xs) = e   : xs
   20   insertDef i e []     = def : insertDef (i-1) e []
   21   insertDef i e (x:xs) = x   : insertDef (i-1) e xs
   22 
   23 instance Default a => InsertDef (Seq a) a where
   24   insertDef i e c = (check <$> Seq.length) c where
   25     check l
   26       | i < l       = Seq.update i e c
   27       | otherwise   = c <> Seq.replicate (i - l) def |> e
   28 
   29 instance InsertDef (IntMap a) a where
   30   insertDef = IntMap.insert