blob: bf25c99bb185db6ca52ac3e5161cef65e5414d36 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
|
{-# LANGUAGE Trustworthy #-}
{-# LANGUAGE NoImplicitPrelude
, RankNTypes
, ExistentialQuantification
#-}
{-# OPTIONS_HADDOCK not-home #-}
-----------------------------------------------------------------------------
-- |
-- Module : GHC.Desugar
-- Copyright : (c) The University of Glasgow, 2007
-- License : see libraries/base/LICENSE
--
-- Maintainer : cvs-ghc@haskell.org
-- Stability : internal
-- Portability : non-portable (GHC extensions)
--
-- Support code for desugaring in GHC
--
-----------------------------------------------------------------------------
module GHC.Desugar ((>>>), AnnotationWrapper(..), toAnnotationWrapper) where
import Control.Arrow (Arrow(..))
import Control.Category ((.))
import Data.Data (Data)
-- A version of Control.Category.>>> overloaded on Arrow
(>>>) :: forall arr. Arrow arr => forall a b c. arr a b -> arr b c -> arr a c
-- NB: the type of this function is the "shape" that GHC expects
-- in tcInstClassOp. So don't put all the foralls at the front!
-- Yes, this is a bit grotesque, but heck it works and the whole
-- arrows stuff needs reworking anyway!
f >>> g = g . f
{-# INLINE (>>>) #-} -- see Note [INLINE on >>>] in Control.Category
-- A wrapper data type that lets the typechecker get at the appropriate dictionaries for an annotation
data AnnotationWrapper = forall a. (Data a) => AnnotationWrapper a
toAnnotationWrapper :: (Data a) => a -> AnnotationWrapper
toAnnotationWrapper what = AnnotationWrapper what
|
