see previous commit and scale back the part where i'm joking
This commit is contained in:
crumbtoo
@@ -1,381 +0,0 @@
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{-# LANGUAGE RecursiveDo #-}
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{-# LANGUAGE ViewPatterns #-}
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{-# LANGUAGE ImplicitParams #-}
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{-# LANGUAGE LambdaCase, BlockArguments #-}
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{-# LANGUAGE OverloadedStrings #-}
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{-# LANGUAGE ScopedTypeVariables #-}
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module Rlp.Parse.Decls
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(
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)
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where
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----------------------------------------------------------------------------------
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import Control.Monad
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import Control.Monad.State
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import Text.Megaparsec hiding (State)
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import Text.Megaparsec.Char
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import Text.Megaparsec.Char.Lexer qualified as L
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import Data.Functor.Classes
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import Data.Functor.Foldable
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import Data.Text (Text)
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import Data.Text qualified as T
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import Data.HashMap.Strict qualified as H
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import Data.Maybe (maybeToList)
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import Data.List (foldl1')
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import Data.Char
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import Data.Function (fix)
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import Data.Functor
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import Data.Functor.Const
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import Data.Fix hiding (cata)
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import GHC.Exts (IsString)
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import Lens.Micro
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import Lens.Micro.Platform
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import Rlp.Parse.Types
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import Rlp.Parse.Utils
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import Rlp.Syntax
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----------------------------------------------------------------------------------
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parseTest' :: (Show a) => Parser a -> Text -> IO ()
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parseTest' p s = case runState (runParserT p "test" s) init of
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(Left e, _) -> putStr (errorBundlePretty e)
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(Right x, st) -> print st *> print x
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where
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init = ParserState mempty
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lexeme :: Parser a -> Parser a
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lexeme = L.lexeme sc
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symbol :: Text -> Parser Text
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symbol = L.symbol sc
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sc :: Parser ()
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sc = L.space hspace1 (void lineComment) (void blockComment)
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scn :: Parser ()
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scn = L.space space1 (void lineComment) (void blockComment)
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type OnFold = (?foldGuard :: Parser ())
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-- TODO: return comment text
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-- TODO: '---' should not start a comment
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lineComment :: Parser Text
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lineComment = L.skipLineComment "--" $> "<unimpl>"
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-- TODO: return comment text
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blockComment :: Parser Text
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blockComment = L.skipBlockCommentNested "{-" "-}" $> "<unimpl>"
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layout :: forall a. ((OnFold) => Parser a) -> Parser [a]
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layout item = scn *> (explicit <|> implicit) where
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explicit :: Parser [a]
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explicit = let ?foldGuard = scn -- line folds just go to the semicolon
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in sym "{" *> fix \items -> choice
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[ sym "}" $> []
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, (:) <$> item
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<*> (sym ";" *> items <|> sym "}" $> [])
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]
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where
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sym = L.symbol scn
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implicit :: Parser [a]
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implicit = do
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i <- L.indentLevel
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-- items must be aligned
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let indentGuard = L.indentGuard scn EQ i
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-- override foldGuard in order with new indentation
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let ?foldGuard = void $ L.indentGuard scn GT i
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fix \ds -> (:) <$> (indentGuard *> item <* scn)
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<*> (ds <|> pure [])
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t :: (?foldGuard :: Parser ()) => Parser [Text]
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t = (:) <$> lexeme "soge" <*> many (flexeme "doge")
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decl :: (OnFold) => Parser PartialDecl'
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decl = choice
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-- declarations that begin with a keyword before those beginning with an
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-- arbitrary name
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[ infixD
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, dataD
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, try funD
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, tySigD
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]
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funD :: (OnFold) => Parser PartialDecl'
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funD = FunD <$> lexeme varid <*> params <*> (fsymbol "=" *> body) <*> whereClause
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where
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params = many pat1
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body = fmap Const partialExpr
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-- we may not need to call scn here
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fsymbol :: (OnFold) => Text -> Parser Text
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fsymbol p = try ?foldGuard *> symbol p
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-- we may not need to call scn here
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flexeme :: (OnFold) => Parser a -> Parser a
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flexeme p = try ?foldGuard *> lexeme p
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whereClause :: Parser Where'
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whereClause = optionalList $
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lexeme "where" *> pure
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[ FunB "fixme" [] (VarE "fixme")
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]
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standalonePartialExpr :: Parser PartialExpr'
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standalonePartialExpr = standaloneOf partialExpr
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where ?foldGuard = undefined
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standaloneOf :: Parser a -> Parser a
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standaloneOf = (<* eof)
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partialExpr :: (OnFold) => Parser PartialExpr'
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partialExpr = choice
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[ ifExpr
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, try $ infixExpr
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, application
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]
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<?> "expression"
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where
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application = foldl1' mkApp <$> some (flexeme partialExpr1)
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infixExpr = fmap Fix $
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mkB <$> partialExpr1' <*> infixOp' <*> partialExpr'
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ifExpr :: Parser PartialExpr'
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ifExpr = fmap (Fix . E) $
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IfEF <$> (flexeme "if" *> partialExpr)
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<*> (flexeme "then" *> partialExpr)
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<*> (flexeme "else" *> partialExpr)
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mkB a f b = B f a b
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partialExpr1' = unFix <$> partialExpr1
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partialExpr' = unFix <$> partialExpr
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infixOp' = flexeme infixOp
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mkApp :: PartialExpr' -> PartialExpr' -> PartialExpr'
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mkApp f x = Fix . E $ f `AppEF` x
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partialExpr1 :: (OnFold) => Parser PartialExpr'
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partialExpr1 = choice
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[ try $ lexeme "(" *> partialExpr' <* lexeme ")"
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, Fix <$> varid'
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, Fix <$> lit'
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]
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<?> "expression"
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where
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partialExpr' = wrapFix . P . unwrapFix <$> partialExpr
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varid' = E . VarEF <$> varid
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lit' = E . LitEF <$> lit
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infixOp :: Parser Name
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infixOp = symvar <|> symcon <?> "operator"
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symvar :: Parser Name
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symvar = T.cons <$> satisfy isVarSym <*> takeWhileP Nothing isSym
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symcon :: Parser Name
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symcon = T.cons <$> char ':' <*> takeWhileP Nothing isSym
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pat1 :: (OnFold) => Parser Pat'
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pat1 = VarP <$> flexeme varid
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<?> "pattern"
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conid :: Parser ConId
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conid = NameCon <$> lexeme namecon
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<|> SymCon <$> lexeme (char '(' *> symcon <* char ')')
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<?> "constructor identifier"
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namecon :: Parser Name
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namecon = T.cons <$> satisfy isUpper <*> takeWhileP Nothing isNameTail
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varid :: Parser VarId
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varid = NameVar <$> try (lexeme namevar)
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<|> SymVar <$> lexeme (char '(' *> symvar <* char ')')
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<?> "variable identifier"
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program :: Parser [Decl' RlpExpr]
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program = do
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ds <- layout decl <* eof
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pt <- use psOpTable
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pure $ complete pt <$> ds
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namevar :: Parser Name
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namevar = word
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& withPredicate (`notElem` keywords) empty
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where
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word = T.cons <$> satisfy isLower <*> takeWhileP Nothing isNameTail
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keywords :: (IsString a) => [a]
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keywords =
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[ "where"
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, "infix"
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, "infixr"
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, "infixl"
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]
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isNameTail :: Char -> Bool
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isNameTail c = isAlphaNum c
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|| c == '\''
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|| c == '_'
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isVarSym :: Char -> Bool
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isVarSym = (`T.elem` "\\!#$%&*+./<=>?@^|-~")
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isSym :: Char -> Bool
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isSym c = c == ':' || isVarSym c
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infixD :: Parser (Decl' e)
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infixD = do
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o <- getOffset
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a <- infixWord
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p <- prec
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op <- infixOp
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region (setErrorOffset o) $ updateOpTable a p op
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pure $ InfixD a p op
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where
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infixWord :: Parser Assoc
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infixWord = choice $ lexeme <$>
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[ "infixr" $> InfixR
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, "infixl" $> InfixL
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, "infix" $> Infix
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]
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prec :: Parser Int
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prec = do
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o <- getOffset
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n <- lexeme L.decimal <?> "precedence level (an integer)"
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if 0 <= n && n <= 9 then
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pure n
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else
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region (setErrorOffset o) $
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registerCustomFailure (RlpParErrOutOfBoundsPrecedence n)
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$> 9
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updateOpTable :: Assoc -> Int -> Name -> Parser ()
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updateOpTable a p op = do
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t <- use psOpTable
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psOpTable <~ H.alterF f op t
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where
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f Nothing = pure (Just (a,p))
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f (Just x) = registerCustomFailure RlpParErrDuplicateInfixD
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$> Just x
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tySigD :: (OnFold) => Parser (Decl' e)
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tySigD = TySigD <$> (pure <$> varid) <*> (flexeme "::" *> flexeme type_)
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dataD :: (OnFold) => Parser (Decl' e)
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dataD = DataD <$> (lexeme "data" *> conid) <*> many typaram
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<*> optionalList (symbol "=" *> conalts)
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where
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typaram :: Parser Name
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typaram = lexeme namevar
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conalts :: Parser [ConAlt]
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conalts = (:) <$> conalt <*> optionalList (symbol "|" *> conalts)
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conalt :: Parser ConAlt
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conalt = ConAlt <$> conid <*> many type1
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type1 :: (OnFold) => Parser Type
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type1 = choice
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[ lexeme "(" *> type_ <* lexeme ")"
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, TyVar <$> namevar
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, TyCon <$> namecon
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]
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type_ :: (OnFold) => Parser Type
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type_ = choice
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[ try $ (:->) <$> type1 <*> (flexeme "->" *> type_)
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, type1
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]
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lit :: Parser Lit'
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lit = int
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<?> "literal"
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where
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int = IntL <$> L.decimal
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--------------------------------------------------------------------------------
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-- completing partial expressions
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complete :: OpTable -> PartialDecl' -> Decl' RlpExpr
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complete pt (FunD n as b w) = FunD n as b' w
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where b' = let ?pt = pt in completeExpr (getConst b)
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complete pt (TySigD ns t) = TySigD ns t
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complete pt (DataD n as cs) = DataD n as cs
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complete pt (InfixD a p n) = InfixD a p n
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completeExpr :: (?pt :: OpTable) => PartialExpr' -> RlpExpr'
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completeExpr = cata completePartial
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completePartial :: (?pt :: OpTable) => PartialE -> RlpExpr'
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completePartial (E e) = completeRlpExpr e
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completePartial p@(B o l r) = completeB (build p)
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completePartial (P e) = completePartial e
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completeRlpExpr :: (?pt :: OpTable) => RlpExprF' RlpExpr' -> RlpExpr'
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completeRlpExpr = embed
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completeB :: (?pt :: OpTable) => PartialE -> RlpExpr'
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completeB p = case build p of
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B o l r -> (o' `AppE` l') `AppE` r'
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where
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-- TODO: how do we know it's symbolic?
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o' = VarE (SymVar o)
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l' = completeB l
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r' = completeB r
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P e -> completeB e
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E e -> completeRlpExpr e
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build :: (?pt :: OpTable) => PartialE -> PartialE
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build e = go id e (rightmost e) where
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rightmost :: PartialE -> PartialE
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rightmost (B _ _ r) = rightmost r
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rightmost p@(E _) = p
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rightmost p@(P _) = p
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go :: (?pt :: OpTable)
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=> (PartialE -> PartialE)
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-> PartialE -> PartialE -> PartialE
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go f p@(WithInfo o _ r) = case r of
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E _ -> mkHole o (f . f')
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P _ -> mkHole o (f . f')
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B _ _ _ -> go (mkHole o (f . f')) r
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where f' r' = p & pR .~ r'
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go f _ = id
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mkHole :: (?pt :: OpTable)
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=> OpInfo
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-> (PartialE -> PartialE)
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-> PartialE
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-> PartialE
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mkHole _ hole p@(P _) = hole p
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mkHole _ hole p@(E _) = hole p
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mkHole (a,d) hole p@(WithInfo (a',d') _ _)
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| d' < d = above
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| d' > d = below
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| d == d' = case (a,a') of
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-- left-associative operators of equal precedence are
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-- associated left
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(InfixL,InfixL) -> above
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-- right-associative operators are handled similarly
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(InfixR,InfixR) -> below
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-- non-associative operators of equal precedence, or equal
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-- precedence operators of different associativities are
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-- invalid
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(_, _) -> error "invalid expression"
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where
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above = p & pL %~ hole
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below = hole p
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examplePrecTable :: OpTable
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examplePrecTable = H.fromList
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[ ("+", (InfixL,6))
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, ("*", (InfixL,7))
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, ("^", (InfixR,8))
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, (".", (InfixR,7))
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, ("~", (Infix, 9))
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, ("=", (Infix, 4))
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, ("&&", (Infix, 3))
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, ("||", (Infix, 2))
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, ("$", (InfixR,0))
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, ("&", (InfixL,0))
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]
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@@ -1,57 +1,97 @@
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{-# LANGUAGE TemplateHaskell #-}
|
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{-# LANGUAGE LambdaCase #-}
|
||||
{-# LANGUAGE ImplicitParams, ViewPatterns, PatternSynonyms #-}
|
||||
{-
|
||||
Description : Supporting types for the parser
|
||||
-}
|
||||
module Rlp.Parse.Types
|
||||
(
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-- * Partial ASTs
|
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Partial(..)
|
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, PartialE
|
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, PartialExpr'
|
||||
, PartialDecl'
|
||||
, pattern WithInfo
|
||||
, pR
|
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, pL
|
||||
|
||||
-- * Parser types
|
||||
, Parser
|
||||
, ParserState(..)
|
||||
, psOpTable
|
||||
, RlpParseError(..)
|
||||
, OpTable
|
||||
, OpInfo
|
||||
)
|
||||
where
|
||||
----------------------------------------------------------------------------------
|
||||
import Control.Monad.State
|
||||
import Data.HashMap.Strict qualified as H
|
||||
{-# LANGUAGE LambdaCase #-}
|
||||
module Rlp.Parse.Types where
|
||||
--------------------------------------------------------------------------------
|
||||
import Core.Syntax (Name)
|
||||
import Control.Monad
|
||||
import Control.Monad.State.Class
|
||||
import Data.Text (Text)
|
||||
import Data.Maybe
|
||||
import Data.Fix
|
||||
import Data.Functor.Foldable
|
||||
import Data.Functor.Const
|
||||
import Data.Functor.Classes
|
||||
import Data.Void
|
||||
import Data.Maybe
|
||||
import Text.Megaparsec hiding (State)
|
||||
import Text.Printf
|
||||
import Lens.Micro
|
||||
import Data.HashMap.Strict qualified as H
|
||||
import Data.Word (Word8)
|
||||
import Lens.Micro.TH
|
||||
import Lens.Micro
|
||||
import Rlp.Syntax
|
||||
----------------------------------------------------------------------------------
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
-- parser types
|
||||
type LexerAction a = AlexInput -> Int -> P a
|
||||
|
||||
-- TODO: the State is only used for building an operator table from infix[lr]
|
||||
-- declarations. we should switch to a normal Parsec monad in the future
|
||||
|
||||
type Parser = ParsecT RlpParseError Text (State ParserState)
|
||||
|
||||
data ParserState = ParserState
|
||||
{ _psOpTable :: OpTable
|
||||
data AlexInput = AlexInput
|
||||
{ _aiPrevChar :: Char
|
||||
, _aiSource :: Text
|
||||
, _aiBytes :: [Word8]
|
||||
, _aiPos :: Position
|
||||
}
|
||||
deriving Show
|
||||
|
||||
type Position =
|
||||
( Int -- line
|
||||
, Int -- column
|
||||
)
|
||||
|
||||
data RlpToken
|
||||
-- literals
|
||||
= TokenLitInt Int
|
||||
-- identifiers
|
||||
| TokenVarName Name
|
||||
| TokenConName Name
|
||||
| TokenVarSym Name
|
||||
| TokenConSym Name
|
||||
-- keywords
|
||||
| TokenData
|
||||
| TokenPipe
|
||||
| TokenLet
|
||||
| TokenIn
|
||||
-- control symbols
|
||||
| TokenEquals
|
||||
| TokenSemicolon
|
||||
| TokenLBrace
|
||||
| TokenRBrace
|
||||
-- 'virtual' control symbols, inserted by the lexer without any correlation
|
||||
-- to a specific symbol
|
||||
| TokenSemicolonV
|
||||
| TokenLBraceV
|
||||
| TokenRBraceV
|
||||
| TokenEOF
|
||||
deriving (Show)
|
||||
|
||||
newtype P a = P { runP :: ParseState -> (ParseState, Maybe a) }
|
||||
deriving (Functor)
|
||||
|
||||
instance Applicative P where
|
||||
pure a = P $ \st -> (st,Just a)
|
||||
liftA2 = liftM2
|
||||
|
||||
instance Monad P where
|
||||
p >>= k = P $ \st ->
|
||||
let (st',a) = runP p st
|
||||
in case a of
|
||||
Just x -> runP (k x) st'
|
||||
Nothing -> (st', Nothing)
|
||||
|
||||
instance MonadState ParseState P where
|
||||
state f = P $ \st ->
|
||||
let (a,st') = f st
|
||||
in (st', Just a)
|
||||
|
||||
data ParseState = ParseState
|
||||
{ _psLayoutStack :: [Layout]
|
||||
, _psLexState :: [Int]
|
||||
, _psInput :: AlexInput
|
||||
}
|
||||
|
||||
data Layout = Explicit
|
||||
| Implicit Int
|
||||
deriving (Show, Eq)
|
||||
|
||||
data Located a = Located (Position, Int) a
|
||||
deriving (Show)
|
||||
|
||||
type OpTable = H.HashMap Name OpInfo
|
||||
type OpInfo = (Assoc, Int)
|
||||
|
||||
@@ -61,17 +101,6 @@ data RlpParseError = RlpParErrOutOfBoundsPrecedence Int
|
||||
| RlpParErrDuplicateInfixD
|
||||
deriving (Eq, Ord, Show)
|
||||
|
||||
instance ShowErrorComponent RlpParseError where
|
||||
showErrorComponent = \case
|
||||
-- TODO: wrap text to 80 characters
|
||||
RlpParErrOutOfBoundsPrecedence n ->
|
||||
printf "%d is an invalid precedence level! rl' currently only\
|
||||
\allows custom precedences between 0 and 9 (inclusive).\
|
||||
\ This is an arbitrary limit put in place for legibility\
|
||||
\ concerns, and may change in the future." n
|
||||
RlpParErrDuplicateInfixD ->
|
||||
"duplicate infix decl"
|
||||
|
||||
----------------------------------------------------------------------------------
|
||||
|
||||
-- absolute psycho shit (partial ASTs)
|
||||
@@ -80,7 +109,7 @@ type PartialDecl' = Decl (Const PartialExpr') Name
|
||||
|
||||
data Partial a = E (RlpExprF Name a)
|
||||
| B Name (Partial a) (Partial a)
|
||||
| P (Partial a)
|
||||
| Par (Partial a)
|
||||
deriving (Show, Functor)
|
||||
|
||||
pL :: Traversal' (Partial a) (Partial a)
|
||||
@@ -109,14 +138,13 @@ instance Show1 Partial where
|
||||
liftShowsPrec sp sl p m = case m of
|
||||
(E e) -> showsUnaryWith lshow "E" p e
|
||||
(B f a b) -> showsTernaryWith showsPrec lshow lshow "B" p f a b
|
||||
(P e) -> showsUnaryWith lshow "P" p e
|
||||
(Par e) -> showsUnaryWith lshow "Par" p e
|
||||
where
|
||||
lshow :: forall f. (Show1 f) => Int -> f a -> ShowS
|
||||
lshow = liftShowsPrec sp sl
|
||||
|
||||
type PartialExpr' = Fix Partial
|
||||
|
||||
----------------------------------------------------------------------------------
|
||||
|
||||
makeLenses ''ParserState
|
||||
makeLenses ''AlexInput
|
||||
makeLenses ''ParseState
|
||||
|
||||
|
||||
@@ -1,30 +0,0 @@
|
||||
module Rlp.Parse.Utils
|
||||
( withPredicate
|
||||
, registerCustomFailure
|
||||
, optionalList
|
||||
)
|
||||
where
|
||||
--------------------------------------------------------------------------------
|
||||
import Text.Megaparsec
|
||||
import Rlp.Parse.Types
|
||||
import Data.Set qualified as S
|
||||
import Data.Maybe
|
||||
import Control.Monad
|
||||
--------------------------------------------------------------------------------
|
||||
|
||||
-- TODO: generalise type sig
|
||||
withPredicate :: (a -> Bool)
|
||||
-> Parser a -- ^ action to run should the predicate fail
|
||||
-> Parser a
|
||||
-> Parser a
|
||||
withPredicate f r p = do
|
||||
o <- getOffset
|
||||
a <- p
|
||||
if f a then pure a else setOffset o *> r
|
||||
|
||||
registerCustomFailure :: MonadParsec e s m => e -> m ()
|
||||
registerCustomFailure = registerFancyFailure . S.singleton . ErrorCustom
|
||||
|
||||
optionalList :: Parser [a] -> Parser [a]
|
||||
optionalList = fmap (join . maybeToList) . optional
|
||||
|
||||
Reference in New Issue
Block a user