Factor out T.P.Readers.LaTeX.Table.

author: John MacFarlane <jgm@berkeley.edu> 2021-02-27 21:40:56 -0800
committer: John MacFarlane <jgm@berkeley.edu> 2021-02-27 21:40:56 -0800
commit: 08231f5cdd16e31d38d9d6bf59bc5ca12638b438 (patch)
tree: 5b67f617d33a5aaad2398eac2d944659a7a0edee /src/Text/Pandoc/Readers/LaTeX
parent: 925815bb33b462e1a4c19a8e2c617d403dec0ce7 (diff)
download: pandoc-08231f5cdd16e31d38d9d6bf59bc5ca12638b438.tar.gz
2 files changed, 406 insertions, 0 deletions
diff --git a/src/Text/Pandoc/Readers/LaTeX/Parsing.hs b/src/Text/Pandoc/Readers/LaTeX/Parsing.hs
index c2e10570d..4a9fa03ad 100644
--- a/src/Text/Pandoc/Readers/LaTeX/Parsing.hs
+++ b/src/Text/Pandoc/Readers/LaTeX/Parsing.hs
@@ -54,6 +54,7 @@ module Text.Pandoc.Readers.LaTeX.Parsing
   , comment
   , anyTok
   , singleChar
+  , tokWith
   , specialChars
   , endline
   , blankline
@@ -80,6 +81,10 @@ module Text.Pandoc.Readers.LaTeX.Parsing
   , rawopt
   , overlaySpecification
   , getNextNumber
+  , label
+  , setCaption
+  , resetCaption
+  , env
   ) where
 
 import Control.Applicative (many, (<|>))
@@ -914,3 +919,31 @@ getNextNumber getCurrentNum = do
                Just n  -> [n, 1]
                Nothing -> [1]
 
+label :: PandocMonad m => LP m ()
+label = do
+  controlSeq "label"
+  t <- braced
+  updateState $ \st -> st{ sLastLabel = Just $ untokenize t }
+
+setCaption :: PandocMonad m => LP m Inlines -> LP m ()
+setCaption inline = try $ do
+  skipopts
+  ils <- tokWith inline
+  optional $ try $ spaces *> label
+  updateState $ \st -> st{ sCaption = Just ils }
+
+resetCaption :: PandocMonad m => LP m ()
+resetCaption = updateState $ \st -> st{ sCaption   = Nothing
+                                      , sLastLabel = Nothing }
+
+env :: PandocMonad m => Text -> LP m a -> LP m a
+env name p = p <* end_ name
+
+tokWith :: PandocMonad m => LP m Inlines -> LP m Inlines
+tokWith inlineParser = try $ spaces >>
+                                 grouped inlineParser
+                            <|> (lookAhead anyControlSeq >> inlineParser)
+                            <|> singleChar'
+  where singleChar' = do
+          Tok _ _ t <- singleChar
+          return $ str t
diff --git a/src/Text/Pandoc/Readers/LaTeX/Table.hs b/src/Text/Pandoc/Readers/LaTeX/Table.hs
new file mode 100644
index 000000000..2ea9caf58
--- /dev/null
+++ b/src/Text/Pandoc/Readers/LaTeX/Table.hs
@@ -0,0 +1,373 @@
+{-# LANGUAGE BangPatterns #-}
+{-# LANGUAGE OverloadedStrings #-}
+module Text.Pandoc.Readers.LaTeX.Table
+  ( tableEnvironments )
+where
+
+import Data.Functor (($>))
+import Text.Pandoc.Class
+import Text.Pandoc.Readers.LaTeX.Parsing
+import Text.Pandoc.Readers.LaTeX.Types
+import Text.Pandoc.Builder as B
+import qualified Data.Map as M
+import Data.Text (Text)
+import Data.Maybe (fromMaybe)
+import qualified Data.Text as T
+import Control.Applicative ((<|>), optional, many)
+import Control.Monad (when, void)
+import Text.Pandoc.Shared (safeRead, trim)
+import Text.Pandoc.Logging (LogMessage(SkippedContent))
+import Text.Pandoc.Walk (walkM)
+import Text.Pandoc.Parsing hiding (blankline, many, mathDisplay, mathInline,
+                            optional, space, spaces, withRaw, (<|>))
+
+tableEnvironments :: PandocMonad m
+                  => LP m Blocks
+                  -> LP m Inlines
+                  -> M.Map Text (LP m Blocks)
+tableEnvironments blocks inline =
+  M.fromList
+  [ ("longtable",  env "longtable" $
+          resetCaption *>
+            simpTable blocks inline "longtable" False >>= addTableCaption)
+  , ("table",  env "table" $
+          skipopts *> resetCaption *> blocks >>= addTableCaption)
+  , ("tabular*", env "tabular*" $ simpTable blocks inline "tabular*" True)
+  , ("tabularx", env "tabularx" $ simpTable blocks inline "tabularx" True)
+  , ("tabular", env "tabular"  $ simpTable blocks inline "tabular" False)
+  ]
+
+hline :: PandocMonad m => LP m ()
+hline = try $ do
+  spaces
+  controlSeq "hline" <|>
+    -- booktabs rules:
+    controlSeq "toprule" <|>
+    controlSeq "bottomrule" <|>
+    controlSeq "midrule" <|>
+    controlSeq "endhead" <|>
+    controlSeq "endfirsthead"
+  spaces
+  optional rawopt
+  return ()
+
+lbreak :: PandocMonad m => LP m Tok
+lbreak = (controlSeq "\\" <|> controlSeq "tabularnewline")
+         <* skipopts <* spaces
+
+amp :: PandocMonad m => LP m Tok
+amp = symbol '&'
+
+-- Split a Word into individual Symbols (for parseAligns)
+splitWordTok :: PandocMonad m => LP m ()
+splitWordTok = do
+  inp <- getInput
+  case inp of
+       (Tok spos Word t : rest) ->
+         setInput $ map (Tok spos Symbol . T.singleton) (T.unpack t) <> rest
+       _ -> return ()
+
+parseAligns :: PandocMonad m => LP m [(Alignment, ColWidth, ([Tok], [Tok]))]
+parseAligns = try $ do
+  let maybeBar = skipMany
+        (try $ sp *> (() <$ symbol '|' <|> () <$ (symbol '@' >> braced)))
+  let cAlign = AlignCenter <$ symbol 'c'
+  let lAlign = AlignLeft <$ symbol 'l'
+  let rAlign = AlignRight <$ symbol 'r'
+  let parAlign = AlignLeft <$ symbol 'p'
+  -- aligns from tabularx
+  let xAlign = AlignLeft <$ symbol 'X'
+  let mAlign = AlignLeft <$ symbol 'm'
+  let bAlign = AlignLeft <$ symbol 'b'
+  let alignChar = splitWordTok *> (  cAlign <|> lAlign <|> rAlign <|> parAlign
+                                 <|> xAlign <|> mAlign <|> bAlign )
+  let alignPrefix = symbol '>' >> braced
+  let alignSuffix = symbol '<' >> braced
+  let colWidth = try $ do
+        symbol '{'
+        ds <- trim . untokenize <$> manyTill anyTok (controlSeq "linewidth")
+        spaces
+        symbol '}'
+        return $ safeRead ds
+  let alignSpec = do
+        pref <- option [] alignPrefix
+        spaces
+        al <- alignChar
+        width <- colWidth <|> option Nothing (do s <- untokenize <$> braced
+                                                 pos <- getPosition
+                                                 report $ SkippedContent s pos
+                                                 return Nothing)
+        spaces
+        suff <- option [] alignSuffix
+        return (al, width, (pref, suff))
+  let starAlign = do -- '*{2}{r}' == 'rr', we just expand like a macro
+        symbol '*'
+        spaces
+        ds <- trim . untokenize <$> braced
+        spaces
+        spec <- braced
+        case safeRead ds of
+             Just n  ->
+               getInput >>= setInput . (mconcat (replicate n spec) ++)
+             Nothing -> Prelude.fail $ "Could not parse " <> T.unpack ds <> " as number"
+  bgroup
+  spaces
+  maybeBar
+  aligns' <- many $ try $ spaces >> optional starAlign >>
+                            (alignSpec <* maybeBar)
+  spaces
+  egroup
+  spaces
+  return $ map toSpec aligns'
+  where
+    toColWidth (Just w) | w > 0 = ColWidth w
+    toColWidth _                = ColWidthDefault
+    toSpec (x, y, z) = (x, toColWidth y, z)
+
+-- N.B. this parser returns a Row that may have erroneous empty cells
+-- in it. See the note above fixTableHead for details.
+parseTableRow :: PandocMonad m
+              => LP m Blocks -- ^ block parser
+              -> LP m Inlines -- ^ inline parser
+              -> Text   -- ^ table environment name
+              -> [([Tok], [Tok])] -- ^ pref/suffixes
+              -> LP m Row
+parseTableRow blocks inline envname prefsufs = do
+  notFollowedBy (spaces *> end_ envname)
+  -- add prefixes and suffixes in token stream:
+  let celltoks (pref, suff) = do
+        prefpos <- getPosition
+        contents <- mconcat <$>
+            many ( snd <$> withRaw
+                     ((lookAhead (controlSeq "parbox") >>
+                       void blocks) -- #5711
+                      <|>
+                      (lookAhead (controlSeq "begin") >> void inline)
+                      <|>
+                      (lookAhead (symbol '$') >> void inline))
+                  <|>
+                   (do notFollowedBy
+                         (() <$ amp <|> () <$ lbreak <|> end_ envname)
+                       count 1 anyTok) )
+
+        suffpos <- getPosition
+        option [] (count 1 amp)
+        return $ map (setpos prefpos) pref ++ contents ++ map (setpos suffpos) suff
+  rawcells <- mapM celltoks prefsufs
+  cells <- mapM (parseFromToks (parseTableCell blocks)) rawcells
+  spaces
+  return $ Row nullAttr cells
+
+parseTableCell :: PandocMonad m => LP m Blocks -> LP m Cell
+parseTableCell blocks = do
+  spaces
+  updateState $ \st -> st{ sInTableCell = True }
+  cell' <-   multicolumnCell blocks
+         <|> multirowCell blocks
+         <|> parseSimpleCell
+         <|> parseEmptyCell
+  updateState $ \st -> st{ sInTableCell = False }
+  spaces
+  return cell'
+  where
+    -- The parsing of empty cells is important in LaTeX, especially when dealing
+    -- with multirow/multicolumn. See #6603.
+    parseEmptyCell = spaces $> emptyCell
+    parseSimpleCell = simpleCell <$> (plainify <$> blocks)
+
+
+cellAlignment :: PandocMonad m => LP m Alignment
+cellAlignment = skipMany (symbol '|') *> alignment <* skipMany (symbol '|')
+  where
+    alignment = do
+      c <- untoken <$> singleChar
+      return $ case c of
+        "l" -> AlignLeft
+        "r" -> AlignRight
+        "c" -> AlignCenter
+        "*" -> AlignDefault
+        _   -> AlignDefault
+
+plainify :: Blocks -> Blocks
+plainify bs = case toList bs of
+                [Para ils] -> plain (fromList ils)
+                _          -> bs
+
+multirowCell :: PandocMonad m => LP m Blocks -> LP m Cell
+multirowCell blocks = controlSeq "multirow" >> do
+  -- Full prototype for \multirow macro is:
+  --     \multirow[vpos]{nrows}[bigstruts]{width}[vmove]{text}
+  -- However, everything except `nrows` and `text` make
+  -- sense in the context of the Pandoc AST
+  _ <- optional $ symbol '[' *> cellAlignment <* symbol ']'   -- vertical position
+  nrows <- fmap (fromMaybe 1 . safeRead . untokenize) braced
+  _ <- optional $ symbol '[' *> manyTill anyTok (symbol ']')  -- bigstrut-related
+  _ <- symbol '{' *> manyTill anyTok (symbol '}')             -- Cell width
+  _ <- optional $ symbol '[' *> manyTill anyTok (symbol ']')  -- Length used for fine-tuning
+  content <- symbol '{' *> (plainify <$> blocks) <* symbol '}'
+  return $ cell AlignDefault (RowSpan nrows) (ColSpan 1) content
+
+multicolumnCell :: PandocMonad m => LP m Blocks -> LP m Cell
+multicolumnCell blocks = controlSeq "multicolumn" >> do
+  span' <- fmap (fromMaybe 1 . safeRead . untokenize) braced
+  alignment <- symbol '{' *> cellAlignment <* symbol '}'
+
+  let singleCell = do
+        content <- plainify <$> blocks
+        return $ cell alignment (RowSpan 1) (ColSpan span') content
+
+  -- Two possible contents: either a \multirow cell, or content.
+  -- E.g. \multicol{1}{c}{\multirow{2}{1em}{content}}
+  -- Note that a \multirow cell can be nested in a \multicolumn,
+  -- but not the other way around. See #6603
+  let nestedCell = do
+        (Cell _ _ (RowSpan rs) _ bs) <- multirowCell blocks
+        return $ cell
+                  alignment
+                  (RowSpan rs)
+                  (ColSpan span')
+                  (fromList bs)
+
+  symbol '{' *> (nestedCell <|> singleCell) <* symbol '}'
+
+-- LaTeX tables are stored with empty cells underneath multirow cells
+-- denoting the grid spaces taken up by them. More specifically, if a
+-- cell spans m rows, then it will overwrite all the cells in the
+-- columns it spans for (m-1) rows underneath it, requiring padding
+-- cells in these places. These padding cells need to be removed for
+-- proper table reading. See #6603.
+--
+-- These fixTable functions do not otherwise fix up malformed
+-- input tables: that is left to the table builder.
+fixTableHead :: TableHead -> TableHead
+fixTableHead (TableHead attr rows) = TableHead attr rows'
+  where
+    rows' = fixTableRows rows
+
+fixTableBody :: TableBody -> TableBody
+fixTableBody (TableBody attr rhc th tb)
+  = TableBody attr rhc th' tb'
+  where
+    th' = fixTableRows th
+    tb' = fixTableRows tb
+
+fixTableRows :: [Row] -> [Row]
+fixTableRows = fixTableRows' $ repeat Nothing
+  where
+    fixTableRows' oldHang (Row attr cells : rs)
+      = let (newHang, cells') = fixTableRow oldHang cells
+            rs'               = fixTableRows' newHang rs
+        in Row attr cells' : rs'
+    fixTableRows' _ [] = []
+
+-- The overhang is represented as Just (relative cell dimensions) or
+-- Nothing for an empty grid space.
+fixTableRow :: [Maybe (ColSpan, RowSpan)] -> [Cell] -> ([Maybe (ColSpan, RowSpan)], [Cell])
+fixTableRow oldHang cells
+  -- If there's overhang, drop cells until their total width meets the
+  -- width of the occupied grid spaces (or we run out)
+  | (n, prefHang, restHang) <- splitHang oldHang
+  , n > 0
+  = let cells' = dropToWidth getCellW n cells
+        (restHang', cells'') = fixTableRow restHang cells'
+    in (prefHang restHang', cells'')
+  -- Otherwise record the overhang of a pending cell and fix the rest
+  -- of the row
+  | c@(Cell _ _ h w _):cells' <- cells
+  = let h' = max 1 h
+        w' = max 1 w
+        oldHang' = dropToWidth getHangW w' oldHang
+        (newHang, cells'') = fixTableRow oldHang' cells'
+    in (toHang w' h' <> newHang, c : cells'')
+  | otherwise
+  = (oldHang, [])
+  where
+    getCellW (Cell _ _ _ w _) = w
+    getHangW = maybe 1 fst
+    getCS (ColSpan n) = n
+
+    toHang c r
+      | r > 1     = [Just (c, r)]
+      | otherwise = replicate (getCS c) Nothing
+
+    -- Take the prefix of the overhang list representing filled grid
+    -- spaces. Also return the remainder and the length of this prefix.
+    splitHang = splitHang' 0 id
+
+    splitHang' !n l (Just (c, r):xs)
+      = splitHang' (n + c) (l . (toHang c (r-1) ++)) xs
+    splitHang' n l xs = (n, l, xs)
+
+    -- Drop list items until the total width of the dropped items
+    -- exceeds the passed width.
+    dropToWidth _     n l | n < 1 = l
+    dropToWidth wproj n (c:cs)    = dropToWidth wproj (n - wproj c) cs
+    dropToWidth _     _ []        = []
+
+simpTable :: PandocMonad m
+          => LP m Blocks
+          -> LP m Inlines
+          -> Text
+          -> Bool
+          -> LP m Blocks
+simpTable blocks inline envname hasWidthParameter = try $ do
+  when hasWidthParameter $ () <$ tokWith inline
+  skipopts
+  colspecs <- parseAligns
+  let (aligns, widths, prefsufs) = unzip3 colspecs
+  optional $ controlSeq "caption" *> setCaption inline
+  spaces
+  optional label
+  spaces
+  optional lbreak
+  spaces
+  skipMany hline
+  spaces
+  header' <- option [] . try . fmap (:[]) $
+             parseTableRow blocks inline envname prefsufs <*
+               lbreak <* many1 hline
+  spaces
+  rows <- sepEndBy (parseTableRow blocks inline envname prefsufs)
+                    (lbreak <* optional (skipMany hline))
+  spaces
+  optional $ controlSeq "caption" *> setCaption inline
+  spaces
+  optional label
+  spaces
+  optional lbreak
+  spaces
+  lookAhead $ controlSeq "end" -- make sure we're at end
+  let th  = fixTableHead $ TableHead nullAttr header'
+  let tbs = [fixTableBody $ TableBody nullAttr 0 [] rows]
+  let tf  = TableFoot nullAttr []
+  return $ table emptyCaption (zip aligns widths) th tbs tf
+
+addTableCaption :: PandocMonad m => Blocks -> LP m Blocks
+addTableCaption = walkM go
+  where go (Table attr c spec th tb tf) = do
+          st <- getState
+          let mblabel = sLastLabel st
+          capt <- case (sCaption st, mblabel) of
+                   (Just ils, Nothing)  -> return $ caption Nothing (plain ils)
+                   (Just ils, Just lab) -> do
+                     num <- getNextNumber sLastTableNum
+                     setState
+                       st{ sLastTableNum = num
+                         , sLabels = M.insert lab
+                                    [Str (renderDottedNum num)]
+                                    (sLabels st) }
+                     return $ caption Nothing (plain ils) -- add number??
+                   (Nothing, _)  -> return c
+          let attr' = case (attr, mblabel) of
+                        ((_,classes,kvs), Just ident) ->
+                           (ident,classes,kvs)
+                        _ -> attr
+          return $ addAttrDiv attr' $ Table nullAttr capt spec th tb tf
+        go x = return x
+
+-- TODO: For now we add a Div to contain table attributes, since
+-- most writers don't do anything yet with attributes on Table.
+-- This can be removed when that changes.
+addAttrDiv :: Attr -> Block -> Block
+addAttrDiv ("",[],[]) b = b
+addAttrDiv attr b       = Div attr [b]
author	John MacFarlane <jgm@berkeley.edu>	2021-02-27 21:40:56 -0800
committer	John MacFarlane <jgm@berkeley.edu>	2021-02-27 21:40:56 -0800
commit	08231f5cdd16e31d38d9d6bf59bc5ca12638b438 (patch)
tree	5b67f617d33a5aaad2398eac2d944659a7a0edee /src/Text/Pandoc/Readers/LaTeX
parent	925815bb33b462e1a4c19a8e2c617d403dec0ce7 (diff)
download	pandoc-08231f5cdd16e31d38d9d6bf59bc5ca12638b438.tar.gz