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bundled/Math/NumberTheory/Powers/Integer.hs

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+-- |
+-- Module:      Math.NumberTheory.Powers.Integer
+-- Copyright:   (c) 2011-2014 Daniel Fischer
+-- Licence:     MIT
+-- Maintainer:  Daniel Fischer <daniel.is.fischer@googlemail.com>
+-- Stability:   Provisional
+-- Portability: Non-portable (GHC extensions)
+--
+-- Potentially faster power function for 'Integer' base and 'Int'
+-- or 'Word' exponent.
+--
+{-# LANGUAGE Safe #-}
+module Math.NumberTheory.Powers.Integer
+    {-# DEPRECATED "It is no faster than (^)" #-}
+    ( integerPower
+    , integerWordPower
+    ) where
+
+-- | Power of an 'Integer' by the left-to-right repeated squaring algorithm.
+--   This needs two multiplications in each step while the right-to-left
+--   algorithm needs only one multiplication for 0-bits, but here the
+--   two factors always have approximately the same size, which on average
+--   gains a bit when the result is large.
+--
+--   For small results, it is unlikely to be any faster than '(^)', quite
+--   possibly slower (though the difference shouldn't be large), and for
+--   exponents with few bits set, the same holds. But for exponents with
+--   many bits set, the speedup can be significant.
+--
+--   /Warning:/ No check for the negativity of the exponent is performed,
+--   a negative exponent is interpreted as a large positive exponent.
+integerPower :: Integer -> Int -> Integer
+integerPower = (^)
+{-# DEPRECATED integerPower "Use (^) instead" #-}
+
+-- | Same as 'integerPower', but for exponents of type 'Word'.
+integerWordPower :: Integer -> Word -> Integer
+integerWordPower = (^)
+{-# DEPRECATED integerWordPower "Use (^) instead" #-}