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Use fmapDefault and foldMapDefault

This commit is contained in:
Joe Hermaszewski 2016-09-21 10:33:18 +01:00
parent e2b80391bb
commit f8fa161f5b
1 changed files with 9 additions and 10 deletions
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19
Nix/Expr/Types.hs
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@ -169,20 +169,19 @@ instance IsString (NKeyName r) where
-- | Deriving this instance automatically is not possible because @r@
-- occurs not only as last argument in @Antiquoted (NString r) r@
instance Functor NKeyName where
fmap f (DynamicKey (Plain str)) = DynamicKey . Plain $ fmap f str
fmap f (DynamicKey (Antiquoted e)) = DynamicKey . Antiquoted $ f e
fmap _ (StaticKey key) = StaticKey key
fmap = fmapDefault
-- Deriving this instance automatically is not possible because @r@
-- occurs not only as last argument in @Antiquoted (NString r) r@
instance Foldable NKeyName where
foldMap f = \case
DynamicKey (Plain str) -> foldMap f str
DynamicKey (Antiquoted e) -> f e
StaticKey _ -> mempty
foldMap = foldMapDefault
-- Deriving this instance automatically is not possible because @r@
-- occurs not only as last argument in @Antiquoted (NString r) r@
instance Traversable NKeyName where
sequenceA = \case
DynamicKey (Plain str) -> DynamicKey . Plain <$> sequenceA str
DynamicKey (Antiquoted e) -> DynamicKey . Antiquoted <$> e
traverse f = \case
DynamicKey (Plain str) -> DynamicKey . Plain <$> traverse f str
DynamicKey (Antiquoted e) -> DynamicKey . Antiquoted <$> f e
StaticKey key -> pure (StaticKey key)
-- | A selector (for example in a @let@ or an attribute set) is made up