Implement monoid for ECPoint

1 files changed, 7 insertions, 0 deletions

diff --git a/ecc.hs b/ecc.hs
index 0bdbf02..5bc5d8a 100644
--- a/ecc.hs
+++ b/ecc.hs
@@ -104,6 +104,12 @@ binaryExpansion m value result | m == 0    = result
 scalarProduct :: (Eq a, Fractional a) => Integer -> ECPoint a -> ECPoint a
 scalarProduct m ec = binaryExpansion m ec Infinity
 
+instance (Eq a, Fractional a) => Semigroup (ECPoint a) where
+  (<>) = add
+
+instance (Eq a, Fractional a) => Monoid (ECPoint a) where
+  mempty = Infinity
+
 tre = FieldElement 3 :: FieldElement 31
 cc =
   let a = ECPoint tre (-7) 5 7
@@ -133,6 +139,7 @@ aPoint = ECPoint 192 105 0 7 :: ECPoint (FieldElement 223)
 total = add aPoint $ add aPoint $ add aPoint $ add aPoint aPoint
 
 totalfold=foldr add Infinity $ replicate 5 aPoint
+totalmconcat = mconcat  $ replicate 5 aPoint
 
 type S256Field = FieldElement (2 ^ 256- 2^ 32 - 977)
 type S256Point = ECPoint S256Field