groups 0.5.1 → 0.5.2

raw patch · 2 files changed

+31/−1 lines, 2 filesPVP ok

version bump matches the API change (PVP)

API changes (from Hackage documentation)

Files

• groups.cabal +1/−1
• src/Data/Group.hs +30/−0

@@ -1,6 +1,6 @@ cabal-version:       2.4 name:                groups-version:             0.5.1+version:             0.5.2 synopsis:            Groups description:   A group is a monoid with invertibility.

@@ -6,6 +6,8 @@ module Data.Group where  import Data.Monoid+import Data.Ord+import Data.List (unfoldr) #if MIN_VERSION_base(4,7,0) import Data.Proxy #endif@@ -91,6 +93,10 @@   invert (a, b, c, d, e) = (invert a, invert b, invert c, invert d, invert e)   pow (a, b, c, d, e) n = (pow a n, pow b n, pow c n, pow d n, pow e n) +#if MIN_VERSION_base(4,11,0)+instance Group a => Group (Down a) where+  invert (Down a) = Down (invert a)+#endif  -- |An 'Abelian' group is a 'Group' that follows the rule: --@@ -115,17 +121,36 @@  instance (Abelian a, Abelian b, Abelian c, Abelian d, Abelian e) => Abelian (a, b, c, d, e) +#if MIN_VERSION_base(4,11,0)+instance Abelian a => Abelian (Down a)+#endif  -- | A 'Group' G is 'Cyclic' if there exists an element x of G such that for all y in G, there exists an n, such that -- -- @y = pow x n@ class Group a => Cyclic a where+  -- | The generator of the 'Cyclic' group.   generator :: a +-- | Generate all elements of a 'Cyclic' group using its 'generator'.+--+-- /Note:/ Fuses, does not terminate even for finite groups.+-- generated :: Cyclic a => [a] generated =   iterate (mappend generator) mempty +-- | Lazily generate all elements of a 'Cyclic' group using its 'generator'.+--+-- /Note:/ Fuses, terminates if the underlying group is finite.+--+generated' :: (Eq a, Cyclic a) => [a]+generated' = unfoldr go (generator, 0 :: Integer)+  where+    go (a, n)+      | a == mempty, n > 0 = Nothing+      | otherwise = Just (a, (a <> generator, succ n))+ instance Cyclic () where   generator = () @@ -194,4 +219,9 @@   pow (Op f) n = Op (\e -> pow (f e) n)  instance Abelian a => Abelian (Op a b)+#endif++#if MIN_VERSION_base(4,11,0)+instance Cyclic a => Cyclic (Down a) where+  generator = Down generator #endif