poly-arity 0.0.5 → 0.0.6

raw patch · 2 files changed

+21/−1 lines, 2 filesPVP ok

version bump matches the API change (PVP)

API changes (from Hackage documentation)

Files

• poly-arity.cabal +1/−1
• src/Data/Function/Poly.hs +20/−0

@@ -1,5 +1,5 @@ Name:                   poly-arity-Version:                0.0.5+Version:                0.0.6 Author:                 Athan Clark <athan.clark@gmail.com> Maintainer:             Athan Clark <athan.clark@gmail.com> License:                BSD3

@@ -29,6 +29,10 @@   ArityToTypeList (x -> r) = x ': ArityToTypeList r   ArityToTypeList r = '[] +type family Result (f :: *) :: * where+  Result (x -> r) = Result r+  Result r = 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 @->@.@@ -36,11 +40,27 @@   ArityMinusTypeList r '[] = r -- basis   ArityMinusTypeList (x -> r) (x ': xs) = ArityMinusTypeList r xs +-- | Injects a type to the base of the function arity chain.+type family InjectLast (x :: *) (f :: *) :: * where+  InjectLast x f = TypeListToArity (Append (ArityToTypeList f) x) (Result f)+++type family Append (xs :: [*]) (x :: *) :: [*] where+  Append '[] y = y ': '[]+  Append (x ': xs) y = x ': Append xs y+++ -- | 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++-- | Expect the last parameter in your stack of arity to have a type.+type family ExpectLast (x :: *) (f :: *) :: Constraint where+  ExpectLast x (x -> remainder) = () -- basis+  ExpectLast x (y -> remainder) = ExpectLast x 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.