Several combinators (#97)

* Added `both`

* Added `sans`

* Update changelog

* Update src/Data/Lens/Traversal.purs

Co-authored-by: Thomas Honeyman <[email protected]>

* Use `set` rather than `.~`

Co-authored-by: JordanMartinez <[email protected]>
Co-authored-by: Thomas Honeyman <[email protected]>

Author: 3 people

CHANGELOG.md

@@ -7,6 +7,7 @@ Notable changes to this project are documented in this file. The format is based
 Breaking changes:
 
 New features:
+- Add `sans` and `both` (#97 by @xgrommx)
 
 Bugfixes:
 

src/Data/Lens/At.purs

@@ -1,13 +1,14 @@
 module Data.Lens.At
   ( class At
   , at
+  , sans
   ) where
 
 
 import Prelude
 
 import Data.Identity (Identity(..))
-import Data.Lens (Lens', lens)
+import Data.Lens (Lens', lens, set)
 import Data.Lens.Index (class Index)
 import Data.Map as M
 import Data.Maybe (Maybe(..), maybe, maybe')
@@ -60,3 +61,6 @@ instance atForeignObject :: At (FO.Object v) String v where
   at k =
     lens (FO.lookup k) \m ->
       maybe' (\_ -> FO.delete k m) \v -> FO.insert k v m
+
+sans :: forall m a b. At m a b => a -> m -> m
+sans k = at k `set` Nothing

src/Data/Lens/Traversal.purs

@@ -27,13 +27,15 @@ module Data.Lens.Traversal
   , itraverseOf
   , iforOf
   , cloneTraversal
+  , both
   , module ExportTypes
   ) where
 
 import Prelude
 
 import Control.Alternative (class Alternative)
 import Control.Plus (empty)
+import Data.Bitraversable (class Bitraversable, bitraverse)
 import Data.Lens.Indexed (iwander, positions, unIndex)
 import Data.Lens.Internal.Bazaar (Bazaar(..), runBazaar)
 import Data.Lens.Types (ATraversal, IndexedTraversal, IndexedOptic, Indexed(..), Traversal, Optic, class Wander, wander)
@@ -147,3 +149,6 @@ iforOf = flip <<< itraverseOf
 
 cloneTraversal :: forall s t a b. ATraversal s t a b -> Traversal s t a b
 cloneTraversal l = wander (runBazaar (l (Bazaar identity)))
+
+both :: forall r a b. Bitraversable r => Traversal (r a a) (r b b) a b
+both = wander (join bitraverse)