{-# OPTIONS_GHC -fno-warn-orphans #-}
module Data.Validity.Map
( decorateMap
) where
import Data.Map (Map)
import qualified Data.Map as M
import Data.Validity
instance (Show k, Ord k, Validity k, Validity v) => Validity (Map k v) where
validate m =
mconcat
[ declare "The Map structure is valid." $ M.valid m
, decorate "Map elements" $
decorateMap m $ \k v -> mconcat [delve "The key" k, delve "The value" v]
]
decorateMap :: Show k => Map k v -> (k -> v -> Validation) -> Validation
decorateMap m func = M.foldMapWithKey go m
where
go k v = decorate ("The key/value at key " ++ show k) $ func k v