symantic/Language/Symantic/Typing/Grammar.hs

   1 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
   2 {-# LANGUAGE UndecidableInstances #-}
   3 {-# OPTIONS_GHC -fno-warn-orphans #-}
   4 module Language.Symantic.Typing.Grammar where
   5
   6 import Control.Applicative (Applicative(..))
   7 import Data.List (foldl1')
   8 import Data.String (IsString(..))
   9 import Data.Text (Text)
  10 import qualified Data.Char as Char
  11
  12 import Language.Symantic.Grammar
  13 import Language.Symantic.Typing.Variable
  14
  15 -- * Type 'NameTy'
  16 newtype NameTy = NameTy Text
  17  deriving (Eq, Ord, Show)
  18 instance IsString NameTy where
  19         fromString = NameTy . fromString
  20
  21 -- ** Type 'NameConst'
  22 type NameConst = NameTy
  23
  24 -- ** Type 'NameFam'
  25 type NameFam = NameTy
  26
  27 -- * Type 'AST_Type'
  28 -- | /Abstract Syntax Tree/ of 'Token_Type'.
  29 type AST_Type src = BinTree (Token_Type src) -- (EToken src '[Proxy K.Type])
  30
  31 -- ** Type 'Token_Type'
  32 data Token_Type src
  33  =   Token_Type_Const (At src NameTy)
  34  |   Token_Type_Var   (At src NameVar)
  35  deriving (Eq, Show)
  36
  37 -- * Class 'Gram_Type'
  38 -- | Read an 'AST_Type' from a textual source.
  39 class
  40  ( Gram_Terminal g
  41  , Gram_Rule g
  42  , Gram_Alt g
  43  , Gram_Try g
  44  , Gram_App g
  45  , Gram_AltApp g
  46  , Gram_CF g
  47  , Gram_Comment g
  48  , Gram_Op g
  49  , Gram_Meta (Text_of_Source src) g
  50  , Inj_Source (Text_of_Source src) src
  51  ) => Gram_Type src g where
  52         g_type :: CF g (AST_Type src)
  53         g_type = rule "type" $ g_type_fun
  54         g_type_fun :: CF g (AST_Type src)
  55         g_type_fun = rule "type_fun" $
  56                 infixrG g_type_list (withSource $ op <$ symbol "->")
  57                 where op src = BinTree2 . BinTree2 (BinTree0 $ Token_Type_Const $ At src "(->)")
  58         -- TODO: maybe not harcoding g_type_list and g_type_tuple2
  59         g_type_list :: CF g (AST_Type src)
  60         g_type_list = rule "type_list" $
  61                 withSource $ inside mk
  62                  (symbol "[") (optional g_type) (symbol "]")
  63                  (const <$> g_type_tuple2)
  64                 where
  65                 mk Nothing  src = tok src
  66                 mk (Just a) src = BinTree2 (tok src) a
  67                 tok src = BinTree0 $ Token_Type_Const $ At src "[]"
  68         g_type_tuple2 :: CF g (AST_Type src)
  69         g_type_tuple2 = rule "type_tuple2" $
  70                 try (parens (infixrG (g_type) (withSource $ op <$ symbol ","))) <+> (g_type_app)
  71                 where op src = BinTree2 . BinTree2 (BinTree0 $ Token_Type_Const $ At src "(,)")
  72         g_type_app :: CF g (AST_Type src)
  73         g_type_app = rule "type_app" $
  74                 foldl1' BinTree2 <$> some (g_type_atom)
  75         g_type_atom :: CF g (AST_Type src)
  76         g_type_atom = rule "type_atom" $
  77                 try (parens g_type) <+>
  78                 g_type_name_const <+>
  79                 g_type_name_var <+>
  80                 g_type_symbol
  81         g_type_name_const :: CF g (AST_Type src)
  82         g_type_name_const = rule "type_name_const" $
  83                 lexeme $ withSource $
  84                 (\n ns src -> BinTree0 $ Token_Type_Const $ At src $ fromString $ n:ns)
  85                  <$> unicat (Unicat Char.UppercaseLetter)
  86                  <*> many (choice $ unicat <$> [Unicat_Letter, Unicat_Number])
  87         g_type_name_var :: CF g (AST_Type src)
  88         g_type_name_var = rule "type_name_var" $
  89                 lexeme $ withSource $
  90                 (\n ns src -> BinTree0 $ Token_Type_Var $ At src $ fromString $ n:ns)
  91                  <$> unicat (Unicat Char.LowercaseLetter)
  92                  <*> many (choice $ unicat <$> [Unicat_Letter, Unicat_Number])
  93         g_type_symbol :: CF g (AST_Type src)
  94         g_type_symbol = rule "type_symbol" $
  95                 withSource $ (mk <$>) $
  96                 parens $ many $ cf_of_Terminal $ choice g_ok `but` choice g_ko
  97                 where
  98                 mk s src = BinTree0 $ Token_Type_Const $ At src (fromString $ "(" ++ s ++ ")")
  99                 g_ok = unicat <$>
 100                  [ Unicat_Symbol
 101                  , Unicat_Punctuation
 102                  , Unicat_Mark
 103                  ]
 104                 g_ko = char <$> ['(', ')', '`']
 105
 106 deriving instance Gram_Type src g => Gram_Type src (CF g)
 107 instance Inj_Source (Text_of_Source src) src => Gram_Type src EBNF
 108 instance Inj_Source (Text_of_Source src) src => Gram_Type src RuleEBNF
 109
 110 -- | List of the rules of 'Gram_Type'.
 111 gram_type :: Gram_Type () g => [CF g (AST_Type ())]
 112 gram_type =
 113  [ g_type
 114  , g_type_fun
 115  , g_type_list
 116  , g_type_tuple2
 117  , g_type_app
 118  , g_type_atom
 119  , g_type_name_const
 120  , g_type_name_var
 121  , g_type_symbol
 122  ]