Merge pull request #58 from LuxLang/hierarchy_normalization

Hierarchy normalization

1 files changed, 28 insertions, 0 deletions

diff --git a/stdlib/source/library/lux/abstract/comonad/cofree.lux b/stdlib/source/library/lux/abstract/comonad/cofree.lux
new file mode 100644
index 000000000..c0236f079
--- /dev/null
+++ b/stdlib/source/library/lux/abstract/comonad/cofree.lux
@@ -0,0 +1,28 @@
+(.module:
+  [library
+   [lux #*]]
+  [// (#+ CoMonad)
+   [//
+    [functor (#+ Functor)]]])
+
+(type: #export (CoFree F a)
+  {#.doc "The CoFree CoMonad."}
+  [a (F (CoFree F a))])
+
+(implementation: #export (functor dsl)
+  (All [F] (-> (Functor F) (Functor (CoFree F))))
+  
+  (def: (map f [head tail])
+    [(f head) (\ dsl map (map f) tail)]))
+
+(implementation: #export (comonad dsl)
+  (All [F] (-> (Functor F) (CoMonad (CoFree F))))
+
+  (def: &functor (..functor dsl))
+
+  (def: (unwrap [head tail])
+    head)
+
+  (def: (split [head tail])
+    [[head tail]
+     (\ dsl map split tail)]))