module Text.Quote (
Quote (SingleQuote, DoubleQuote)
, AsQuote (_Quote, _SingleQuote, _DoubleQuote)
, quoteChar
, quoteToString
) where
import Control.DeepSeq (NFData (rnf))
import Control.Lens (Prism', prism, prism', review)
import Data.String (IsString (fromString))
data Quote =
SingleQuote
| DoubleQuote
deriving (Eq, Ord, Show)
instance NFData Quote where
rnf x = seq x ()
class AsQuote r where
_Quote :: Prism' r Quote
_SingleQuote :: Prism' r ()
_DoubleQuote :: Prism' r ()
_SingleQuote = _Quote . _SingleQuote
_DoubleQuote = _Quote . _DoubleQuote
instance AsQuote Quote where
_Quote = id
_SingleQuote = prism (const SingleQuote) $ \x -> case x of
SingleQuote -> Right ()
DoubleQuote -> Left x
_DoubleQuote = prism (const DoubleQuote) $ \x -> case x of
SingleQuote -> Left x
DoubleQuote -> Right ()
instance AsQuote Char where
_Quote = quoteChar
quoteChar :: Prism' Char Quote
quoteChar =
prism'
(\q -> case q of
SingleQuote -> '\''
DoubleQuote -> '"')
(\c -> case c of
'\'' -> Just SingleQuote
'"' -> Just DoubleQuote
_ -> Nothing)
quoteToString :: IsString a => Quote -> a
quoteToString = fromString . pure . review quoteChar