Microdoc

README.md

@@ -1 +1,8 @@
 # First-class type families
+
+See `src/Fcf`.
+
+---
+
+Contributions are welcome. Feel free to open an issue or make a PR on
+[Github](https://github.com/Lysxia/first-class-families)!

first-class-families.cabal

@@ -5,6 +5,8 @@ synopsis:
 description:
   First class type families,
   eval-style defunctionalization
+  .
+  See "Fcf".
 homepage:            https://github.com/Lysxia/first-class-families#readme
 license:             MIT
 license-file:        LICENSE

src/Fcf.hs

@@ -7,6 +7,27 @@
 {-# LANGUAGE TypeOperators #-}
 {-# LANGUAGE UndecidableInstances #-}
 
+-- | First-class type families
+--
+-- For example, here is a regular type family:
+--
+-- @
+-- type family   FromMaybe (a :: k) (m :: Maybe k) :: k
+-- type instance FromMaybe a 'Nothing  = a
+-- type instance FromMaybe a ('Just b) = b
+-- @
+--
+-- With @Fcf@, it translates to a @data@ declaration:
+--
+-- @
+-- data FromMaybe :: k -> Maybe k -> 'Exp' k
+-- type instance 'Eval' (FromMaybe a 'Nothing)  = a
+-- type instance 'Eval' (FromMaybe a ('Just b)) = b
+-- @
+--
+-- - Fcfs can be higher-order.
+-- - The kind constructor 'Exp' is a monad: there's @('=<<')@ and 'Pure'.
+
 module Fcf where
 
 import Data.Kind (Type)