poly-arity 0.0.4.1 → 0.0.5

raw patch · 3 files changed

+21/−4 lines, 3 filessetup-changedPVP: major bump suggested

API removals or changes: PVP suggests a major version bump

API changes (from Hackage documentation)

Files

• Setup.hs +0/−2
• poly-arity.cabal +2/−1
• src/Data/Function/Poly.hs +19/−1

@@ -1,2 +0,0 @@-import Distribution.Simple-main = defaultMain

@@ -1,5 +1,5 @@ Name:                   poly-arity-Version:                0.0.4.1+Version:                0.0.5 Author:                 Athan Clark <athan.clark@gmail.com> Maintainer:             Athan Clark <athan.clark@gmail.com> License:                BSD3@@ -8,6 +8,7 @@ -- Description: Cabal-Version:          >= 1.10 Build-Type:             Simple+Category:               Data, Functions  Library   Default-Language:     Haskell2010

@@ -17,19 +17,33 @@ import Data.Constraint import Data.HList +-- | Provide a type-level list of /types/ @xs@, and a final result type @r@,+-- construct a chain of arrows @->@ / n-ary function (which is right-associative)+-- of each type in @xs@, ending in @r@. type family TypeListToArity (xs :: [*]) (r :: *) :: * where   TypeListToArity '[] r = r -- basis   TypeListToArity (x ': xs) r = x -> TypeListToArity xs r +-- | The inverse of @TypeListToArity@.+type family ArityToTypeList (r :: *) :: [*] where+  ArityToTypeList (x -> r) = x ': ArityToTypeList r+  ArityToTypeList r = '[]++-- | Trim an n-ary function / chain of arrows @->@ with a type-level list of+-- types @xs@, where each element of @xs@ __must__ unify with each element of+-- the cons-list made with @->@. type family ArityMinusTypeList (r :: *) (xs :: [*]) :: * where   ArityMinusTypeList r '[] = r -- basis   ArityMinusTypeList (x -> r) (x ': xs) = ArityMinusTypeList r xs -+-- | Inductively constrain a function's initial arity to match a type list;+-- as a read-only style of static arity assurance. type family ExpectArity (xs :: [*]) (f :: *) :: Constraint where   ExpectArity '[] f = () -- basis   ExpectArity (x ': xs) (x -> remainder) = ExpectArity xs remainder +-- | Duplicate of <http://hackage.haskell.org/package/singletons-1.1.2.1/docs/Data-Promotion-Prelude-List.html#g:1 singletons>+-- @Head@ function for kind-polymorphic type-level lists. type family Head (xs :: [k]) :: k where   Head (x ': xs) = x @@ -37,7 +51,10 @@   Tail (x ': xs) = xs  +-- | Lift the @HList@'s internal type-level list of types to a constraint context. class ExpectArity xs f => ConsumeArity (xs :: [*]) (f :: *) result | xs f -> result where+  -- | Use a /heterogeneously-typed/ list of values as input to an n-ary function,+  -- where types must unify statically.   appN :: f -> HList xs -> result  instance ConsumeArity '[] r r where@@ -48,6 +65,7 @@   appN f (HCons x xs) = appN (f x) xs  +-- | Shows that an n-ary function @f@ /precisely/ ends with @r@. type family HasResult (f :: *) (r :: *) :: Constraint where   HasResult r r = ()   HasResult (x -> r') r = HasResult r' r