diff options
Diffstat (limited to 'src/Haddock/Parser.hs')
| -rw-r--r-- | src/Haddock/Parser.hs | 110 |
1 files changed, 84 insertions, 26 deletions
diff --git a/src/Haddock/Parser.hs b/src/Haddock/Parser.hs index 0d24cf17..b8aa9cb4 100644 --- a/src/Haddock/Parser.hs +++ b/src/Haddock/Parser.hs @@ -1,4 +1,7 @@ {-# LANGUAGE OverloadedStrings #-} +{-# LANGUAGE StandaloneDeriving + , FlexibleInstances, UndecidableInstances + , IncoherentInstances #-} -- | -- Module : Haddock.Parser -- Copyright : (c) Mateusz Kowalczyk 2013, @@ -12,6 +15,7 @@ module Haddock.Parser (parseString, parseParas, parseStringMaybe, parseParasMaybe) where import Prelude hiding (takeWhile) +import Control.Arrow (first) import Control.Monad (void, mfilter) import Control.Applicative import Data.Attoparsec.ByteString.Char8 hiding (parse, take, endOfLine) @@ -208,36 +212,93 @@ orderedList d = (paren <|> dot) *> innerList (orderedList d) d innerList :: Parser [Doc RdrName] -> DynFlags -> Parser [Doc RdrName] innerList item d = do c <- takeLine - (cs, items) <- more - let contents = (docParagraph . parseString d . unlines) (c : cs) - return (contents : items) - where - more :: Parser ([String], [Doc RdrName]) - more = moreListItems <|> moreContent <|> pure ([], []) - - moreListItems :: Parser ([String], [Doc RdrName]) - moreListItems = (,) [] <$> (skipSpace *> item) - - moreContent :: Parser ([String], [Doc RdrName]) - moreContent = mapFst . (:) <$> nonEmptyLine <*> more + (cs, items) <- more item d + let contents = docParagraph . parseString d . dropNLs . unlines $ c : cs + return $ case items of + Left p -> [contents `joinPara` p] + Right i -> contents : i -- | Parses definition lists. definitionList :: DynFlags -> Parser [(Doc RdrName, Doc RdrName)] definitionList d = do - label <- parseStringBS d <$> ("[" *> takeWhile1 (`notElem` "]\n") <* "]") + label <- "[" *> (parseStringBS d <$> takeWhile1 (`notElem` "]\n")) <* "]" c <- takeLine - (cs, items) <- more - let contents = (parseString d . unlines) (c : cs) - return ((label, contents) : items) + (cs, items) <- more (definitionList d) d + let contents = parseString d . dropNLs . unlines $ c : cs + return $ case items of + Left p -> [(label, contents `joinPara` p)] + Right i -> (label, contents) : i + +-- | If possible, appends two 'Doc's under a 'DocParagraph' rather than +-- outside of it. This allows to get structures like +-- +-- @DocParagraph (DocAppend … …)@ +-- +-- rather than +-- +-- @DocAppend (DocParagraph …) …@ +joinPara :: Doc id -> Doc id -> Doc id +joinPara (DocParagraph p) c = docParagraph $ docAppend p c +joinPara d p = docAppend d p + +-- | Drops all trailing newlines. +dropNLs :: String -> String +dropNLs = reverse . dropWhile (== '\n') . reverse + +-- | Main worker for 'innerList' and 'definitionList'. +-- We need the 'Either' here to be able to tell in the respective functions +-- whether we're dealing with the next list or a nested paragraph. +more :: Monoid a => Parser a -> DynFlags + -> Parser ([String], Either (Doc RdrName) a) +more item d = innerParagraphs d <|> moreListItems item + <|> moreContent item d <|> pure ([], Right mempty) + +-- | Use by 'innerList' and 'definitionList' to parse any nested paragraphs. +innerParagraphs :: DynFlags + -> Parser ([String], Either (Doc RdrName) a) +innerParagraphs d = (,) [] . Left <$> ("\n" *> indentedParagraphs d) + +-- | Attemps to fetch the next list if possibly. Used by 'innerList' and +-- 'definitionList' to recursivly grab lists that aren't separated by a whole +-- paragraph. +moreListItems :: Parser a + -> Parser ([String], Either (Doc RdrName) a) +moreListItems item = (,) [] . Right <$> (skipSpace *> item) + +-- | Helper for 'innerList' and 'definitionList' which simply takes +-- a line of text and attempts to parse more list content with 'more'. +moreContent :: Monoid a => Parser a -> DynFlags + -> Parser ([String], Either (Doc RdrName) a) +moreContent item d = first . (:) <$> nonEmptyLine <*> more item d + +-- | Collects and parses the result of 'dropFrontOfPara' +indentedParagraphs :: DynFlags -> Parser (Doc RdrName) +indentedParagraphs d = parseParas d . concat <$> dropFrontOfPara " " + +-- | Grab as many fully indented paragraphs as we can. +dropFrontOfPara :: Parser BS.ByteString -> Parser [String] +dropFrontOfPara sp = do + currentParagraph <- some (sp *> takeNonEmptyLine) + followingParagraphs <- + skipHorizontalSpace *> nextPar -- we have more paragraphs to take + <|> skipHorizontalSpace *> nlList -- end of the ride, remember the newline + <|> endOfInput *> return [] -- nothing more to take at all + return (currentParagraph ++ followingParagraphs) where - more :: Parser ([String], [(Doc RdrName, Doc RdrName)]) - more = moreListItems <|> moreContent <|> pure ([], []) + nextPar = (++) <$> nlList <*> dropFrontOfPara sp + nlList = "\n" *> return ["\n"] - moreListItems :: Parser ([String], [(Doc RdrName, Doc RdrName)]) - moreListItems = (,) [] <$> (skipSpace *> definitionList d) +nonSpace :: BS.ByteString -> Parser BS.ByteString +nonSpace xs + | not $ any (not . isSpace) $ decodeUtf8 xs = fail "empty line" + | otherwise = return xs - moreContent :: Parser ([String], [(Doc RdrName, Doc RdrName)]) - moreContent = mapFst . (:) <$> nonEmptyLine <*> more +-- | Takes a non-empty, not fully whitespace line. +-- +-- Doesn't discard the trailing newline. +takeNonEmptyLine :: Parser String +takeNonEmptyLine = do + (++ "\n") . decodeUtf8 <$> (takeWhile1 (/= '\n') >>= nonSpace) <* "\n" birdtracks :: Parser (Doc a) birdtracks = DocCodeBlock . DocString . intercalate "\n" <$> many1 line @@ -263,7 +324,7 @@ examples = DocExamples <$> (many (skipHorizontalSpace *> "\n") *> go) moreExamples = (,) [] <$> go result :: Parser ([String], [Example]) - result = mapFst . (:) <$> nonEmptyLine <*> resultAndMoreExamples + result = first . (:) <$> nonEmptyLine <*> resultAndMoreExamples makeExample :: String -> String -> [String] -> Example makeExample prefix expression res = @@ -285,9 +346,6 @@ takeLine = decodeUtf8 <$> takeWhile (/= '\n') <* endOfLine endOfLine :: Parser () endOfLine = void "\n" <|> endOfInput -mapFst :: (a -> b) -> (a, c) -> (b, c) -mapFst f (a, b) = (f a, b) - -- | Property parser. -- -- >>> parseOnly property "prop> hello world" |