document the main haskell module

1 files changed, 14 insertions, 0 deletions

diff --git a/haskell/Data/VCDIFF.hs b/haskell/Data/VCDIFF.hs
index a776052..ae8a6af 100644
--- a/haskell/Data/VCDIFF.hs
+++ b/haskell/Data/VCDIFF.hs
@@ -11,6 +11,20 @@
 {-# LANGUAGE RankNTypes                 #-}
 {-# LANGUAGE TypeFamilies               #-}
 {-# LANGUAGE TypeOperators              #-}
+-- |
+--
+-- Create and apply binary diffs in the VCDIFF format.
+--
+-- To create a diff:
+-- > diff = computeDiff defaultConfig source target
+--
+-- To apply a change to produce an updated version:
+-- > target = applyPatch defaultConfig source diff
+--
+-- Unlike typical text patches, context is ignored and
+-- there is no fuzz. This means the file you apply
+-- the patch to must have identical contents to the source
+-- used to create it.
 module Data.VCDIFF where
 
 import Control.Monad