module ASCII.QuasiQuoters ( char, string ) where

import ASCII.Char (Char)
import ASCII.Superset (toCharListMaybe, toCharMaybe)
import ASCII.TemplateHaskell (isCharExp, isCharPat, isStringExp, isStringPat)
import Control.Monad (return, (>=>))
import Control.Monad.Fail (MonadFail, fail)
import Data.Maybe (Maybe (..))
import Language.Haskell.TH.Quote (QuasiQuoter (..))
import Language.Haskell.TH.Syntax (Exp, Pat, Q)

import qualified Data.Char as Unicode
import qualified Data.String as Unicode

{- | Produces an expression or a pattern corresponding to an ASCII character.

The result will have an 'ASCII.Superset.CharSuperset' constraint; since this is polymorphic, use with a type signature to specify the particular you want is recommended.

The quasi-quoted string must consist of a single character that is within the ASCII character set.

>>> :set -XQuasiQuotes

>>> [char|e|] :: ASCII.Char
SmallLetterE

>>> [char|e|] :: Word8
101

Use in a pattern context requires enabling the @ViewPatterns@ language extension.

>>> :set -XViewPatterns

>>> case Tilde of [char|@|] -> 1; [char|~|] -> 2; _ -> 3
2

-}

char :: QuasiQuoter
char :: QuasiQuoter
char = forall a.
(String -> Q a) -> (a -> Q Exp) -> (a -> Q Pat) -> QuasiQuoter
expPatQQ String -> Q Char
requireOneAscii Char -> Q Exp
isCharExp Char -> Q Pat
isCharPat

{- | Produces an expression or a pattern corresponding to an ASCII string.

The result will have an 'ASCII.Superset.StringSuperset' constraint; since this is polymorphic, use with a type signature to specify the particular you want is recommended.

The quasi-quoted string must consist only of characters are within the ASCII character set.

>>> :set -XQuasiQuotes

>>> [string|Hello!|] :: [ASCII.Char]
[CapitalLetterH,SmallLetterE,SmallLetterL,SmallLetterL,SmallLetterO,ExclamationMark]

>>> [string|Hello!|] :: Data.String.String
"Hello!"

>>> [string|Hello!|] :: Data.Text.Text
"Hello!"

>>> Data.ByteString.Builder.toLazyByteString [string|Hello!|]
"Hello!"


Use in a pattern context requires enabling the @ViewPatterns@ language extension.

>>> :set -XViewPatterns

>>> case [CapitalLetterH, SmallLetterI] of [string|Bye|] -> 1; [string|Hi|] -> 2; _ -> 3
2

-}

string :: QuasiQuoter
string :: QuasiQuoter
string = forall a.
(String -> Q a) -> (a -> Q Exp) -> (a -> Q Pat) -> QuasiQuoter
expPatQQ String -> Q [Char]
requireAsciiList [Char] -> Q Exp
isStringExp [Char] -> Q Pat
isStringPat

requireOneAscii :: Unicode.String -> Q Char
requireOneAscii :: String -> Q Char
requireOneAscii = String -> Q Char
requireOne forall (m :: * -> *) a b c.
Monad m =>
(a -> m b) -> (b -> m c) -> a -> m c
>=> Char -> Q Char
requireAscii

oneMaybe :: [a] -> Maybe a
oneMaybe :: forall a. [a] -> Maybe a
oneMaybe [a]
xs = case [a]
xs of [a
x] -> forall a. a -> Maybe a
Just a
x; [a]
_ -> forall a. Maybe a
Nothing

requireOne :: Unicode.String -> Q Unicode.Char
requireOne :: String -> Q Char
requireOne = forall a. [a] -> Maybe a
oneMaybe forall a b. (a -> Maybe b) -> String -> a -> Q b
|| String
"Must be exactly one character."

requireAscii :: Unicode.Char -> Q Char
requireAscii :: Char -> Q Char
requireAscii = forall char. CharSuperset char => char -> Maybe Char
toCharMaybe forall a b. (a -> Maybe b) -> String -> a -> Q b
|| String
"Must be an ASCII character."

requireAsciiList :: Unicode.String -> Q [Char]
requireAsciiList :: String -> Q [Char]
requireAsciiList = forall string. StringSuperset string => string -> Maybe [Char]
toCharListMaybe forall a b. (a -> Maybe b) -> String -> a -> Q b
|| String
"Must be only ASCII characters."

(||) :: (a -> Maybe b) -> Unicode.String -> a -> Q b
a -> Maybe b
f || :: forall a b. (a -> Maybe b) -> String -> a -> Q b
|| String
msg = \a
a -> case a -> Maybe b
f a
a of Just b
b -> forall (m :: * -> *) a. Monad m => a -> m a
return b
b; Maybe b
Nothing -> forall (m :: * -> *) a. MonadFail m => String -> m a
fail String
msg

expPatQQ :: (Unicode.String -> Q a) -> (a -> Q Exp) -> (a -> Q Pat) -> QuasiQuoter
expPatQQ :: forall a.
(String -> Q a) -> (a -> Q Exp) -> (a -> Q Pat) -> QuasiQuoter
expPatQQ String -> Q a
f a -> Q Exp
a a -> Q Pat
b =
    QuasiQuoter
        { quoteExp :: String -> Q Exp
quoteExp  = String -> Q a
f forall (m :: * -> *) a b c.
Monad m =>
(a -> m b) -> (b -> m c) -> a -> m c
>=> a -> Q Exp
a
        , quotePat :: String -> Q Pat
quotePat  = String -> Q a
f forall (m :: * -> *) a b c.
Monad m =>
(a -> m b) -> (b -> m c) -> a -> m c
>=> a -> Q Pat
b
        , quoteType :: String -> Q Type
quoteType = forall (m :: * -> *) a b. MonadFail m => a -> m b
notType
        , quoteDec :: String -> Q [Dec]
quoteDec  = forall (m :: * -> *) a b. MonadFail m => a -> m b
notDec
        }

notType :: MonadFail m => a -> m b
notType :: forall (m :: * -> *) a b. MonadFail m => a -> m b
notType a
_ = forall (m :: * -> *) a. MonadFail m => String -> m a
fail String
"Cannot be used in a type context."

notDec :: MonadFail m => a -> m b
notDec :: forall (m :: * -> *) a b. MonadFail m => a -> m b
notDec a
_ = forall (m :: * -> *) a. MonadFail m => String -> m a
fail String
"Cannot be used in a declaration context."