blob: cdcc37f426fd60a71645c5b773113007756bfefb (
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
|
{-# LANGUAGE GADTs #-}
{-# LANGUAGE TemplateHaskell #-}
{-# LANGUAGE TypeFamilies #-}
{-# LANGUAGE TypeOperators #-}
module Main where
import Data.Function (on)
import Language.Haskell.TH.Syntax
data a :~: b where
Refl :: a ~ b => a :~: b
$(return [])
main :: IO ()
main = print
$(do TyConI (DataD _ _ tycon_tyvars _
[ForallC con_tyvars _ _] _) <- reify ''(:~:)
let tvbName :: TyVarBndr -> Name
tvbName (PlainTV n) = n
tvbName (KindedTV n _) = n
lift $ and $ zipWith ((/=) `on` tvbName) tycon_tyvars con_tyvars)
|
