Add Category instance for Flip (#33)

* Add Category instance for Flip * Update CHANGELOG.md * Fix formatting
purescript · Mar 14, 2021 · e59244d · e59244d
1 parent 81ac75e
commit e59244d
Show file tree

Hide file tree

Showing 2 changed files with 8 additions and 0 deletions.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -8,6 +8,8 @@ Breaking changes:
 
 New features:
 
+- `Semigroupoid` and `Category` instances for `Flip` (#33)
+
 Bugfixes:
 
 Other improvements:

diff --git a/src/Data/Functor/Flip.purs b/src/Data/Functor/Flip.purs
@@ -36,3 +36,9 @@ instance biapplicativeFlip :: Biapplicative p => Biapplicative (Flip p) where
 
 instance contravariantFlip :: Profunctor p => Contravariant (Flip p b) where
   cmap f (Flip a) = Flip (lcmap f a)
+
+instance semigroupoidFlip :: Semigroupoid p => Semigroupoid (Flip p) where
+  compose (Flip a) (Flip b) = Flip $ compose b a
+
+instance categoryFlip :: Category p => Category (Flip p) where
+  identity = Flip identity