validity-containers-0.2.0.0: src/Data/Validity/Set.hs

{-# OPTIONS_GHC -fno-warn-orphans #-}

module Data.Validity.Set where

import Data.Validity

import Data.Set (Set)
import qualified Data.Set as S

-- | A 'Set' of things is valid if all the elements are valid and the 'Set' itself
-- is valid.
instance (Ord v, Validity v) => Validity (Set v) where
    isValid s = S.valid s && all isValid (S.toList s)
    validate s =
        mconcat
            [ S.valid s <?@> "The set structure is valid."
            , all isValid (S.toList s) <?!> "Set elements"
            ]