Added ~. and ~.. for composing functions that take implicit parameter…

…s with functions that take implicit parameters.

implicit-params.cabal

@@ -1,5 +1,5 @@
 name:           implicit-params
-version:        0.2.0.1
+version:        0.2.1
 synopsis:       Named and unnamed implicit parameters with defaults.
 license:        BSD3
 license-file:   LICENSE
@@ -28,7 +28,7 @@ library
     Data.Implicit
 
   build-depends:
-    base >= 4.2 && < 5,
+    base >= 4 && < 5,
     data-default-class > 0 && < 0.1
 
   ghc-options: -Wall

src/Data/Implicit.hs

@@ -110,12 +110,14 @@ module Data.Implicit
     , param
     , setParam
     , (~$)
+    , (~..)
     , ($$)
 
     , Implicit_
     , param_
     , setParam_
     , ($~)
+    , (~.)
     )
 where
 
@@ -160,6 +162,14 @@ infixl 1 ~$
 {-# INLINE (~$) #-}
 
 
+------------------------------------------------------------------------------
+-- | Modify a named implicit parameter.
+(~..) :: Implicit s a => (Implicit s b => c) -> proxy s -> (a -> b) -> c
+(~..) f proxy g = f ~$ proxy $$ g (param proxy)
+infixl 8 ~..
+{-# INLINE ~.. #-}
+
+
 ------------------------------------------------------------------------------
 -- | A left-associated version of '$'.
 ($$) :: (a -> b) -> a -> b
@@ -200,3 +210,11 @@ setParam_ a f = unsafeCoerce (Param_ f :: Param_ a b) a
 infixl 1 $~
 f $~ a = unsafeCoerce (Param_ f :: Param_ a b) a
 {-# INLINE ($~) #-}
+
+
+------------------------------------------------------------------------------
+-- | Modify an unnamed implicit parameter.
+(~.) :: Implicit_ a => (Implicit_ b => c) -> (a -> b) -> c
+f ~. g = f $~ g param_
+infixl 8 ~.
+{-# INLINE ~. #-}