{-# LANGUAGE NoMonomorphismRestriction #-}
{-# LANGUAGE Rank2Types #-}
{-# LANGUAGE TemplateHaskell #-}
{-# LANGUAGE UnboxedTuples #-}
module Parsers.Tiny where

import Control.Monad (Monad(..))
import Data.Char (Char)
import Data.Either (Either(..))
import Data.Function (($))
import Data.Semigroup (Semigroup(..))
import Data.String (String, IsString(..))
import Data.Text (Text)
import Data.Text.IO (readFile)
import System.IO (IO, FilePath)
import Test.Tasty
import Test.Tasty.Golden
import Text.Show (Show(..))
import qualified Data.ByteString.Lazy as BSL
import qualified Data.IORef as IORef
import qualified Data.Text.Lazy as TL
import qualified Data.Text.Lazy.Encoding as TL
import qualified Language.Haskell.TH.Syntax as TH

import qualified Symantic.Parser as P
import qualified Symantic.Parser.Haskell as H
--import Golden.Utils


p_Tiny       = p_CmdSeq P.<* P.eof -- (!. / %{eof})
p_CmdSeq     = P.some (p_Cmd p_SEMICOLON{-^cmdSeq-})
p_Cmd        = p_IfCmd <|> p_RepeatCmd / p_ReadCmd / p_WriteCmd  / p_AssignCmd

-- conditional :: Eq a => [H.Haskell (a -> Bool)] -> [repr b] -> repr a -> repr b -> repr b
p_Cmd = P.conditional
  []
  [p_IfCmd, p_RepeatCmd, p_ReadCmd, p_WriteCmd, p_AssignCmd]

  empty
  
  ((\c -> haskell c [||c||]) Prelude.<$> ["", ])
  (look anyChar) op empty


p_IfCmd      = p_IF  p_Exp^ifExp  p_THEN^ifThen  p_CmdSeq^ifThenCmdSeq  (p_ELSE p_CmdSeq^ifElseCmdSeq / '')  p_END^ifEnd
p_RepeatCmd  = p_REPEAT  p_CmdSeq^repeatCmdSeq  p_UNTIL^repeatUntil  p_Exp^repeatExp
p_AssignCmd  = p_NAME  p_ASSIGNMENT^assignOp  p_Exp^assignExp
p_ReadCmd    = p_READ  p_NAME^readName
p_WriteCmd   = p_WRITE  p_Exp^writeExp
p_Exp        = p_SimpleExp  ((p_LESS / p_EQUAL)  p_SimpleExp^simpleExp / '')
p_SimpleExp  = p_Term  ((p_ADD / p_SUB)  p_Term^term)*
p_Term       = p_Factor ((p_MUL / p_DIV)  p_Factor^factor)*
p_Factor     = p_OPENPAR  p_Exp^openParExp  p_CLOSEPAR^closePar  / p_NUMBER  / p_NAME
p_ADD        = lex "+"
p_ASSIGNMENT = lex ":="
p_CLOSEPAR   = lex ")"
p_DIV        = lex "/"
p_IF         = lex "if"
p_ELSE       = lex "else"
p_END        = lex "end"
p_EQUAL      = lex "="
p_LESS       = lex "<"
p_MUL        = lex "*"
p_NAME       = !p_RESERVED lex (some (oneOf ['a' .. 'z']))
p_NUMBER     = lex (some (oneOf ['0' .. '9']))
p_OPENPAR    = lex "("
p_READ       = lex "read"
p_REPEAT     = lex "repeat"
p_SEMICOLON  = lex ";"
p_SUB        = lex "-"
p_THEN       = lex "then"
p_UNTIL      = lex "until"
p_WRITE      = lex "write"
p_RESERVED   = (p_IF / p_ELSE / p_END / p_READ / p_REPEAT / p_THEN / p_UNTIL / p_WRITE) ![a-z]+
p_Sp         = (" " P.<|> "\n")*
lex = (p_Sp *>)