-- Hoogle documentation, generated by Haddock
-- See Hoogle, http://www.haskell.org/hoogle/


-- | Polyvariadic functions mapping to a given monoid
--   
--   A polyvariadic function takes an indefinite number of possibly
--   differently typed parameters. polyToMonoid provides two polyvariadic
--   functions that map their parameters into a given monoid.
@package polyToMonoid
@version 0.1


-- | Creates polyvariadic functions that map their parameters into a given
--   monoid.
module Data.PolyToMonoid

-- | Define instances of Monoidable to tell Haskell how to convert your
--   parameters into values in the underlying monoid
class Monoid m => Monoidable a m
toMonoid :: Monoidable a m => a -> m

-- | Conceptually, ptm is defined as:
--   
--   <pre>
--   ptm (mempty :: MyMonoid) p1 p2 ... pN =
--       (toMonoid p1) `mappend` (toMonoid p2) `mappend` ... `mappend` (toMonoid pN)
--   </pre>
class Monoid m => PolyVariadic m r
ptm :: PolyVariadic m r => m -> r

-- | ctm is a composable variant of ptm.
--   
--   To actually get its value, use the terminator function trm.
class Monoid m => CPolyVariadic m r
ctm :: CPolyVariadic m r => m -> r
data Terminate m
Terminate :: m -> Terminate m

-- | Use the terminator function trm to get the value of a ctm calculation.
trm :: Terminate m -> m
instance [incoherent] (Monoidable a m, PolyVariadic m r) => PolyVariadic m (a -> r)
instance [incoherent] (m' ~ m, Monoid m') => PolyVariadic m m'
instance [incoherent] (Monoidable a m, CPolyVariadic m r) => CPolyVariadic m (a -> r)
instance [incoherent] (m' ~ m, Monoid m') => CPolyVariadic m (Terminate m')