Add a Vector class and make TwoTuple (and several base types) instances of it.

[numerical-analysis.git] / src / Vector.hs

diff --git a/src/Vector.hs b/src/Vector.hs
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+++ b/src/Vector.hs
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+{-# LANGUAGE FlexibleInstances #-}
+
+-- | The 'Vector' class represents elements of a normed vector
+--   space. We define instances for all common numeric types.
+module Vector
+where
+
+import Data.Number.BigFloat
+
+class Vector a where
+  norm :: RealFrac b => a -> b
+
+-- Define instances for common numeric types.
+instance Vector Integer where
+  norm = fromInteger
+
+instance Vector Rational where
+  norm = fromRational
+
+instance Epsilon e => Vector (BigFloat e) where
+  norm = fromRational . toRational
+
+instance Vector Double where
+  norm = fromRational . toRational