{-# LANGUAGE DefaultSignatures #-}
{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE TypeFamilies #-}
{-# LANGUAGE TypeOperators #-}
-- | Expression for 'Integer'.
module Language.Symantic.Expr.Integer where

import Data.Proxy
import qualified Data.Text as Text

import Language.Symantic.Type
import Language.Symantic.Repr
import Language.Symantic.Expr.Root
import Language.Symantic.Expr.Error
import Language.Symantic.Expr.From
import Language.Symantic.Trans.Common

-- * Class 'Sym_Int'
-- | Symantic.
class Sym_Integer repr where
	integer :: Integer -> repr Integer
	default integer :: Trans t repr => Integer -> t repr Integer
	integer = trans_lift . integer
instance Sym_Integer Repr_Host where
	integer = Repr_Host
instance Sym_Integer Repr_Text where
	integer a = Repr_Text $ \_p _v ->
		Text.pack (show a)
instance (Sym_Integer r1, Sym_Integer r2) => Sym_Integer (Repr_Dup r1 r2) where
	integer x = integer x `Repr_Dup` integer x

sym_Integer :: Proxy Sym_Integer
sym_Integer = Proxy

-- * Type 'Expr_Integer'
-- | Expression.
data Expr_Integer (root:: *)
type instance Root_of_Expr      (Expr_Integer root)      = root
type instance Type_of_Expr      (Expr_Integer root)      = Type_Integer
type instance Sym_of_Expr       (Expr_Integer root) repr = Sym_Integer repr
type instance Error_of_Expr ast (Expr_Integer root)      = No_Error_Expr