{-# LANGUAGE GADTs, TemplateHaskell, TypeOperators #-} {-# OPTIONS_GHC -fno-warn-orphans #-} {-| Module: Text.Show.Text.Data.Type.Equality Copyright: (C) 2014-2015 Ryan Scott License: BSD-style (see the file LICENSE) Maintainer: Ryan Scott Stability: Experimental Portability: GHC Monomorphic 'Show' function for propositional equality. This module is only available with @base-4.7.0.0@ or later. /Since: 0.3/ -} module Text.Show.Text.Data.Type.Equality (showbPropEquality) where import Data.Text.Lazy.Builder (Builder) import Data.Type.Equality ((:~:)(..)) import Prelude hiding (Show) import Text.Show.Text.Classes (Show(showb, showbPrec), Show1(showbPrec1)) import Text.Show.Text.TH.Internal (mkShowbPrec) -- | Convert a propositional equality value to a 'Builder'. -- This function is only available with @base-4.7.0.0@ or later. -- -- /Since: 0.3/ showbPropEquality :: (a :~: b) -> Builder showbPropEquality = showb {-# INLINE showbPropEquality #-} -- TODO: Derive with TH once it can detect phantom types properly instance Show (a :~: b) where showbPrec = $(mkShowbPrec ''(:~:)) {-# INLINE showb #-} instance Show1 ((:~:) a) where showbPrec1 = showbPrec {-# INLINE showbPrec1 #-}