Binary expansion semigroup

1 files changed, 3 insertions, 3 deletions

diff --git a/ecc.hs b/ecc.hs
index 5bc5d8a..42a9220 100644
--- a/ecc.hs
+++ b/ecc.hs
@@ -95,11 +95,11 @@ add p q
     in  ECPoint new_x new_y (a p) (b p)
 
 
-binaryExpansion :: (Eq a, Fractional a) => Integer -> ECPoint a -> ECPoint a -> ECPoint a
+binaryExpansion :: (Semigroup a) => Integer -> a -> a -> a
 binaryExpansion m value result | m == 0    = result
-                               | otherwise = binaryExpansion (m `shiftR` 1) (add value value) accumulator
+                               | otherwise = binaryExpansion (m `shiftR` 1) (value <> value) accumulator
       where
-        accumulator = if m .&. 1 == 1 then add result value else result
+        accumulator = if m .&. 1 == 1 then result <> value else result
 
 scalarProduct :: (Eq a, Fractional a) => Integer -> ECPoint a -> ECPoint a
 scalarProduct m ec = binaryExpansion m ec Infinity