Permutation.hs

{-
wish list:
 - custom Permutation type with Arbitrary instance
-}
{-# LANGUAGE NoImplicitPrelude #-}
module Test.Sound.Synthesizer.Generic.Permutation (tests) where

import qualified Synthesizer.Generic.Permutation as Permutation

import Test.QuickCheck (quickCheck, )

import NumericPrelude.Numeric
import NumericPrelude.Base
import Prelude ()


tests :: [(String, IO ())]
tests =
   ("inverse transposition",
      quickCheck $ \n0 m0 ->
         let n = mod n0 100
             m = mod m0 100
         in  Permutation.inverse (Permutation.transposition n m)
             ==
             Permutation.transposition m n) :
   ("inverse skewGrid",
      quickCheck $ \n0 m0 ->
         let g = gcd n0 m0
             (n,m) = if g==0 then (0,0) else (abs (div n0 g), abs (div m0 g))
         in  Permutation.inverse (Permutation.skewGrid n m)
             ==
             Permutation.skewGridInv n m) :
   ("inverse skewGridCRT",
      quickCheck $ \n0 m0 ->
         let g = gcd n0 m0
             (n,m) = if g==0 then (0,0) else (abs (div n0 g), abs (div m0 g))
         in  Permutation.inverse (Permutation.skewGridCRT n m)
             ==
             Permutation.skewGridCRTInv n m) :
   {-
   reverse (multiplicative (generator n) n)
   ==
   multiplicative (recip $ generator n) n
   -}
   []