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{-# LANGUAGE Arrows #-}
{-# LANGUAGE TemplateHaskell #-}
{-# LANGUAGE UnicodeSyntax #-}
-- See Trac #10162 and #11743 for details
module ShouldCompile where
import Control.Arrow
import Language.Haskell.TH
handle :: ArrowPlus a => a (b,s) c -> a (b,(String,s)) c -> a (b,s) c
handle f h = proc (b,s) -> (f -< (b,s)) <+> (h -< (b,("FAIL",s)))
f :: ArrowPlus a => a (Int,Int) String
f = proc (x,y) ->
⦇handle
(returnA -< show y)
(\s -> returnA -< s ++ show x)
⦈
g :: ArrowPlus a => a (Int,Int) String
g = proc (x,y) ->
⦇handle
(\msg -> returnA -< msg ++ show y)
(\s msg -> returnA -< s ++ show x)
⦈ ("hello " ++ show x)
h :: ArrowPlus a => a (Int,Int) Int
h = proc (x,y) ->
(
(\z -> returnA -< x + z)
<+>
(\z -> returnA -< y + z)
) (x*y)
matches :: PatQ -> ExpQ
matches pat = ⟦\x ->
case x of
$pat -> True
_ -> False
⟧
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