{-# LANGUAGE DeriveLift #-} -- For TH.Lift (ErrorItem tok)
{-# LANGUAGE StandaloneDeriving #-} -- For Show (ErrorItem (InputToken inp))
{-# LANGUAGE TemplateHaskell #-}
+-- | Semantic of the grammar combinators used to express parsers,
+-- in the convenient tagless-final encoding.
module Symantic.Parser.Grammar.Combinators where
import Data.Bool (Bool(..), not, (||))
import Data.Maybe (Maybe(..))
import Data.Ord (Ord)
import Data.String (String)
-import Language.Haskell.TH (CodeQ)
import Text.Show (Show(..))
import qualified Data.Functor as Functor
import qualified Data.List as List
+import qualified Language.Haskell.TH as TH
import qualified Language.Haskell.TH.Syntax as TH
import qualified Symantic.Univariant.Trans as Sym
-import qualified Symantic.Parser.Staging as H
+import qualified Symantic.Parser.Haskell as H
+
+-- * Type 'TermGrammar'
+type TermGrammar = H.Term H.ValueCode
-- * Class 'Applicable'
-- | This is like the usual 'Functor' and 'Applicative' type classes
--- from the @base@ package, but using @('H.Haskell' a)@ instead of just @(a)@
--- to be able to use and pattern match on some usual terms of type @(a)@ (like
--- 'H.id') and thus apply some optimizations.
--- @(repr)@ , for "representation", is the usual tagless-final abstraction
+-- from the @base@ package, but using @('TermGrammar' a)@ instead of just @(a)@
+-- to be able to use and pattern match on some usual terms of type @(a)@ (like 'H.id')
+-- and thus apply some optimizations.
+-- @(repr)@, for "representation", is the usual tagless-final abstraction
-- over the many semantics that this syntax (formed by the methods
-- of type class like this one) will be interpreted.
class Applicable repr where
-- | @(a2b '<$>' ra)@ parses like @(ra)@ but maps its returned value with @(a2b)@.
- (<$>) :: H.Haskell (a -> b) -> repr a -> repr b
+ (<$>) :: TermGrammar (a -> b) -> repr a -> repr b
(<$>) f = (pure f <*>)
-- | Like '<$>' but with its arguments 'flip'-ped.
- (<&>) :: repr a -> H.Haskell (a -> b) -> repr b
+ (<&>) :: repr a -> TermGrammar (a -> b) -> repr b
(<&>) = flip (<$>)
-- | @(a '<$' rb)@ parses like @(rb)@ but discards its returned value by replacing it with @(a)@.
- (<$) :: H.Haskell a -> repr b -> repr a
+ (<$) :: TermGrammar a -> repr b -> repr a
(<$) x = (pure x <*)
-- | @(ra '$>' b)@ parses like @(ra)@ but discards its returned value by replacing it with @(b)@.
- ($>) :: repr a -> H.Haskell b -> repr b
+ ($>) :: repr a -> TermGrammar b -> repr b
($>) = flip (<$)
-- | @('pure' a)@ parses the empty string, always succeeding in returning @(a)@.
- pure :: H.Haskell a -> repr a
+ pure :: TermGrammar a -> repr a
default pure ::
Sym.Liftable repr => Applicable (Sym.Output repr) =>
- H.Haskell a -> repr a
+ TermGrammar a -> repr a
pure = Sym.lift . pure
-- | @(ra2b '<*>' ra)@ parses sequentially @(ra2b)@ and then @(ra)@,
-- | @('liftA2' a2b2c ra rb)@ parses sequentially @(ra)@ and then @(rb)@,
-- and returns the application of @(a2b2c)@ to the values returned by those parsers.
- liftA2 :: H.Haskell (a -> b -> c) -> repr a -> repr b -> repr c
+ liftA2 :: TermGrammar (a -> b -> c) -> repr a -> repr b -> repr c
liftA2 f x = (<*>) (f <$> x)
-- | @(ra '<*' rb)@ parses sequentially @(ra)@ and then @(rb)@,
p <+> q = H.left <$> p <|> H.right <$> q
infixl 3 <|>, <+>
-optionally :: Applicable repr => Alternable repr => repr a -> H.Haskell b -> repr b
+optionally :: Applicable repr => Alternable repr => repr a -> TermGrammar b -> repr b
optionally p x = p $> x <|> pure x
optional :: Applicable repr => Alternable repr => repr a -> repr ()
optional = flip optionally H.unit
-option :: Applicable repr => Alternable repr => H.Haskell a -> repr a -> repr a
+option :: Applicable repr => Alternable repr => TermGrammar a -> repr a -> repr a
option x p = p <|> pure x
choice :: Alternable repr => [repr a] -> repr a
-- * Class 'Matchable'
class Matchable repr where
conditional ::
- Eq a => [H.Haskell (a -> Bool)] -> [repr b] -> repr a -> repr b -> repr b
+ Eq a => repr a -> [TermGrammar (a -> Bool)] -> [repr b] -> repr b -> repr b
default conditional ::
- Sym.Unliftable repr => Sym.Liftable2 repr => Matchable (Sym.Output repr) =>
- Eq a => [H.Haskell (a -> Bool)] -> [repr b] -> repr a -> repr b -> repr b
- conditional cs bs = Sym.lift2 (conditional cs (Sym.trans Functor.<$> bs))
+ Sym.Unliftable repr => Sym.Liftable1 repr => Matchable (Sym.Output repr) =>
+ Eq a => repr a -> [TermGrammar (a -> Bool)] -> [repr b] -> repr b -> repr b
+ conditional a ps bs = Sym.lift1 (conditional (Sym.trans a) ps (Sym.trans Functor.<$> bs))
- match :: Eq a => [H.Haskell a] -> repr a -> (H.Haskell a -> repr b) -> repr b -> repr b
- match as a a2b = conditional (H.eq Functor.<$> as) (a2b Functor.<$> as) a
+ match :: Eq a => repr a -> [TermGrammar a] -> (TermGrammar a -> repr b) -> repr b -> repr b
+ match a as a2b = conditional a ((H.eq H..@) Functor.<$> as) (a2b Functor.<$> as)
+ -- match a as a2b = conditional a (((H.eq H..@ H.qual) H..@) Functor.<$> as) (a2b Functor.<$> as)
-- * Class 'Foldable'
class Foldable repr where
where go = (H..) <$> op <*> go <|> pure H.id
{-
-conditional :: Selectable repr => [(H.Haskell (a -> Bool), repr b)] -> repr a -> repr b -> repr b
+conditional :: Selectable repr => [(TermGrammar (a -> Bool), repr b)] -> repr a -> repr b -> repr b
conditional cs p def = match p fs qs def
where (fs, qs) = List.unzip cs
-}
-- * Class 'Satisfiable'
-class Satisfiable repr tok where
- satisfy :: [ErrorItem tok] -> H.Haskell (tok -> Bool) -> repr tok
+class Satisfiable tok repr where
+ satisfy :: [ErrorItem tok] -> TermGrammar (tok -> Bool) -> repr tok
default satisfy ::
- Sym.Liftable repr => Satisfiable (Sym.Output repr) tok =>
+ Sym.Liftable repr => Satisfiable tok (Sym.Output repr) =>
[ErrorItem tok] ->
- H.Haskell (tok -> Bool) -> repr tok
+ TermGrammar (tok -> Bool) -> repr tok
satisfy es = Sym.lift . satisfy es
+ item :: repr tok
+ item = satisfy [] (H.const H..@ H.bool True)
+
-- ** Type 'ErrorItem'
data ErrorItem tok
= ErrorItemToken tok
| ErrorItemLabel String
+ | ErrorItemHorizon Int
| ErrorItemEnd
deriving instance Eq tok => Eq (ErrorItem tok)
deriving instance Ord tok => Ord (ErrorItem tok)
eof :: repr ()
eof = Sym.lift eof
default eof :: Sym.Liftable repr => Lookable (Sym.Output repr) => repr ()
- -- eof = negLook (satisfy @_ @Char [ErrorItemAny] (H.const H..@ H.bool True))
- -- (item @_ @Char)
+ -- eof = negLook (satisfy @Char [ErrorItemAny] (H.const H..@ H.bool True))
+ -- (item @Char)
{-# INLINE (<:>) #-}
infixl 4 <:>
between :: Applicable repr => repr o -> repr c -> repr a -> repr a
between open close p = open *> p <* close
-string :: Applicable repr => Satisfiable repr Char => [Char] -> repr [Char]
-string = traverse char
-
--- oneOf :: [Char] -> repr Char
--- oneOf cs = satisfy [] (makeQ (flip elem cs) [||\c -> $$(ofChars cs [||c||])||])
-
-noneOf :: TH.Lift tok => Eq tok => Satisfiable repr tok => [tok] -> repr tok
-noneOf cs = satisfy (ErrorItemToken Functor.<$> cs) (H.Haskell H.ValueCode{..})
- where
- value = H.Value (not . flip List.elem cs)
- code = [||\c -> not $$(ofChars cs [||c||])||]
-
-ofChars :: TH.Lift tok => Eq tok => [tok] -> CodeQ tok -> CodeQ Bool
-ofChars = List.foldr (\c rest qc -> [|| c == $$qc || $$(rest qc) ||]) (const [||False||])
-
-more :: Applicable repr => Satisfiable repr Char => Lookable repr => repr ()
-more = look (void (item @_ @Char))
-
-char :: Applicable repr => Satisfiable repr Char => Char -> repr Char
-char c = satisfy [ErrorItemToken c] (H.eq (H.char c)) $> H.char c
-
-anyChar :: Satisfiable repr Char => repr Char
+string ::
+ Applicable repr => Alternable repr =>
+ Satisfiable Char repr =>
+ [Char] -> repr [Char]
+string = try . traverse char
+
+oneOf ::
+ TH.Lift tok => Eq tok =>
+ Satisfiable tok repr =>
+ [tok] -> repr tok
+oneOf ts = satisfy [ErrorItemLabel "oneOf"]
+ (Sym.trans H.ValueCode
+ { value = (`List.elem` ts)
+ , code = [||\t -> $$(ofChars ts [||t||])||] })
+
+noneOf ::
+ TH.Lift tok => Eq tok =>
+ Satisfiable tok repr =>
+ [tok] -> repr tok
+noneOf cs = satisfy (ErrorItemToken Functor.<$> cs) (Sym.trans H.ValueCode
+ { value = not . (`List.elem` cs)
+ , code = [||\c -> not $$(ofChars cs [||c||])||]
+ })
+
+ofChars ::
+ TH.Lift tok => Eq tok =>
+ {-alternatives-}[tok] ->
+ {-input-}TH.CodeQ tok ->
+ TH.CodeQ Bool
+ofChars = List.foldr (\alt acc ->
+ \inp -> [|| alt == $$inp || $$(acc inp) ||])
+ (const [||False||])
+
+more :: Applicable repr => Satisfiable Char repr => Lookable repr => repr ()
+more = look (void (item @Char))
+
+char ::
+ Applicable repr => Satisfiable Char repr =>
+ Char -> repr Char
+char c = satisfy [ErrorItemToken c] (H.eq H..@ H.char c) $> H.char c
+-- char c = satisfy [ErrorItemToken c] (H.eq H..@ H.qual H..@ H.char c) $> H.char c
+
+anyChar :: Satisfiable Char repr => repr Char
anyChar = satisfy [] (H.const H..@ H.bool True)
token ::
- TH.Lift tok => Eq tok => Applicable repr =>
- Satisfiable repr tok => tok -> repr tok
-token tok = satisfy [ErrorItemToken tok] (H.eq (H.char tok)) $> H.char tok
+ TH.Lift tok => Show tok => Eq tok =>
+ Applicable repr => Satisfiable tok repr =>
+ tok -> repr tok
+token tok = satisfy [ErrorItemToken tok] (H.eq H..@ H.char tok) $> H.char tok
+-- token tok = satisfy [ErrorItemToken tok] (H.eq H..@ H.qual H..@ H.char tok) $> H.char tok
tokens ::
- TH.Lift tok => Eq tok => Applicable repr => Alternable repr =>
- Satisfiable repr tok => [tok] -> repr [tok]
+ TH.Lift tok => Eq tok => Show tok =>
+ Applicable repr => Alternable repr =>
+ Satisfiable tok repr => [tok] -> repr [tok]
tokens = try . traverse token
-item :: Satisfiable repr tok => repr tok
-item = satisfy [] (H.const H..@ H.bool True)
-
-- Composite Combinators
-- someTill :: repr a -> repr b -> repr [a]
-- someTill p end = negLook end *> (p <:> manyTill p end)
-- Lift Operations
liftA2 ::
Applicable repr =>
- H.Haskell (a -> b -> c) -> repr a -> repr b -> repr c
+ TermGrammar (a -> b -> c) -> repr a -> repr b -> repr c
liftA2 f x = (<*>) (fmap f x)
liftA3 ::
Applicable repr =>
- H.Haskell (a -> b -> c -> d) -> repr a -> repr b -> repr c -> repr d
+ TermGrammar (a -> b -> c -> d) -> repr a -> repr b -> repr c -> repr d
liftA3 f a b c = liftA2 f a b <*> c
-}
-- Parser Folds
pfoldr ::
Applicable repr => Foldable repr =>
- H.Haskell (a -> b -> b) -> H.Haskell b -> repr a -> repr b
+ TermGrammar (a -> b -> b) -> TermGrammar b -> repr a -> repr b
pfoldr f k p = chainPre (f <$> p) (pure k)
pfoldr1 ::
Applicable repr => Foldable repr =>
- H.Haskell (a -> b -> b) -> H.Haskell b -> repr a -> repr b
+ TermGrammar (a -> b -> b) -> TermGrammar b -> repr a -> repr b
pfoldr1 f k p = f <$> p <*> pfoldr f k p
pfoldl ::
Applicable repr => Foldable repr =>
- H.Haskell (b -> a -> b) -> H.Haskell b -> repr a -> repr b
+ TermGrammar (b -> a -> b) -> TermGrammar b -> repr a -> repr b
pfoldl f k p = chainPost (pure k) ((H.flip <$> pure f) <*> p)
pfoldl1 ::
Applicable repr => Foldable repr =>
- H.Haskell (b -> a -> b) -> H.Haskell b -> repr a -> repr b
+ TermGrammar (b -> a -> b) -> TermGrammar b -> repr a -> repr b
pfoldl1 f k p = chainPost (f <$> pure k <*> p) ((H.flip <$> pure f) <*> p)
-- Chain Combinators
chainl1' ::
Applicable repr => Foldable repr =>
- H.Haskell (a -> b) -> repr a -> repr (b -> a -> b) -> repr b
+ TermGrammar (a -> b) -> repr a -> repr (b -> a -> b) -> repr b
chainl1' f p op = chainPost (f <$> p) (H.flip <$> op <*> p)
chainl1 ::
chainr1 :: repr a -> repr (a -> a -> a) -> repr a
chainr1 = chainr1' H.id
-chainr :: repr a -> repr (a -> a -> a) -> H.Haskell a -> repr a
+chainr :: repr a -> repr (a -> a -> a) -> TermGrammar a -> repr a
chainr p op x = option x (chainr1 p op)
-}
chainl ::
Applicable repr => Alternable repr => Foldable repr =>
- repr a -> repr (a -> a -> a) -> H.Haskell a -> repr a
+ repr a -> repr (a -> a -> a) -> TermGrammar a -> repr a
chainl p op x = option x (chainl1 p op)
-- Derived Combinators
sourcephile / git / haskell / symantic-parser.git / blobdiff