suckless-conf/lib/Data/Config/Suckless/Parse/Megaparsec.hs

148 lines
3.4 KiB
Haskell

module Data.Config.Suckless.Parse.Megaparsec
where
import Data.Config.Suckless.Syntax
import Control.Applicative()
import Data.Char (showLitChar)
import Data.Text qualified as Text
import Text.Megaparsec
import Text.Megaparsec.Char (space1,char,letterChar,digitChar)
import Text.Megaparsec.Char.Lexer qualified as L
import Text.Megaparsec.Char.Lexer ( signed )
import Data.String(IsString(..))
import Debug.Trace
type Parser r = Parsec () [Char] r
type ParseFail = ParseErrorBundle [Char] ()
sc :: Parser ()
sc = do
L.space space1 lineComment empty
where
lineComment = L.skipLineComment ";"
dquot :: Parser Char
dquot = char '"'
-- FIXME: position!
stringLit :: Monoid (Context c) => Parser (Syntax c)
stringLit = L.lexeme sc $
Literal mempty . LitStr <$> str
where
str = do
s <- dquot >> manyTill L.charLiteral dquot
pure $ Text.pack (mconcat [ showLitChar c "" | c <- s ])
{-
-- FIXME: position!
intLit :: Parser Syntax
intLit = L.lexeme sc $
Literal . LitInt <$> choice [hex, oct, bin, dec, dec']
where
hex = L.symbol sc "0x" >> L.hexadecimal
oct = L.symbol sc "0o" >> L.octal
bin = L.symbol sc "0b" >> L.binary
dec = L.decimal
dec'= signed sc L.decimal
symbolChars :: [Char]
symbolChars = "!$%&|*+-/:<=>?@^_~#.'"
symbolChar :: Parser Char
symbolChar = oneOf symbolChars
-- FIXME: position!
symbol :: Parser Syntax
symbol = L.lexeme sc $ do
co <- Context . Just <$> getOffset
h <- letterChar <|> symbolChar
t <- many (letterChar <|> digitChar <|> symbolChar)
case Symbol (fromString (h:t)) of
SymbolVal "#t" -> pure $ Literal (mkLit True)
SymbolVal "#f" -> pure $ Literal (mkLit False)
SymbolVal other -> pure (Symbol_ co other)
skipChar :: Char -> Parser ()
skipChar c = void $ char c
oParen :: Parser ()
oParen = skipChar '('
cParen :: Parser ()
cParen = skipChar ')'
oBrace :: Parser ()
oBrace = skipChar '{'
cBrace :: Parser ()
cBrace = skipChar '}'
oBracket :: Parser ()
oBracket= skipChar '['
cBracket :: Parser ()
cBracket = skipChar ']'
someEnclosedBy :: Parser ()
-> Parser a
-> Parser ()
-> Parser [a]
someEnclosedBy o i c = do
between o c (many (sc >> i)) -- <|> parseError (error (show ("WTF!", ctx))) -- (ParseError (ListParseError ctx))
list :: Parser Syntax
list = L.lexeme sc $ do
co <- Context . Just <$> getOffset
-- traceShowM ("List", co)
List_ co <$> choice [ someEnclosedBy oParen syntax cParen
, someEnclosedBy oBrace syntax cBrace
, someEnclosedBy oBracket syntax cBracket
]
syntax :: Parser Syntax
syntax = choice [ symbol
, stringLit
, intLit
, list
]
-- top :: Parser (AST (Core S))
-- top = sc >> many syntaxWithPos >>= toAST
-- where
-- -- FIXME: push real position here
-- syntaxWithPos = do
-- pos <- getOffset
-- node <- (pos,) <$> syntax
-- pure node
-- toAST xs = go xs
-- go :: [(Int, Syntax)] -> Parser (AST (Core S))
-- go ( (p, syn) : rest ) = do
-- let c = Context (Just p)
-- mkExpr c . Seq syn <$> go rest
-- go [] = pure $ mkLeaf0 ()
-- merely :: Parser a -> Parser a
-- merely f = do
-- sc
-- r <- f
-- sc
-- eof
-- pure r
-- parseSyntax :: String -> Either ParseFail Syntax
-- parseSyntax = parse (merely syntax) "input"
-- parseTop :: String -> Either ParseFail (AST (Core S))
-- parseTop = parse top "input"
-}