Better looking simple tables. Resolves Issue #180.

* Markdown reader: simple tables are now given column widths of 0.

* Column width of 0 is interpreted as meaning: use default column width.

* Writers now include explicit column width information only
  for multiline tables.  (Exception:  RTF writer, which requires
  column widths.  In this case, columns are given equal widths,
  adding up to the text width.)

* Simple tables should now look better in most output formats.

git-svn-id: https://pandoc.googlecode.com/svn/trunk@1631 788f1e2b-df1e-0410-8736-df70ead52e1b

10 files changed, 71 insertions, 41 deletions

diff --git a/src/Text/Pandoc/Definition.hs b/src/Text/Pandoc/Definition.hs
index 92ce094d4..8b91ba322 100644
--- a/src/Text/Pandoc/Definition.hs
+++ b/src/Text/Pandoc/Definition.hs
@@ -86,9 +86,9 @@ data Block
     | HorizontalRule        -- ^ Horizontal rule
     | Table [Inline] [Alignment] [Double] [[Block]] [[[Block]]]  -- ^ Table,
                             -- with caption, column alignments,
-                            -- relative column widths, column headers
-                            -- (each a list of blocks), and rows
-                            -- (each a list of lists of blocks)
+                            -- relative column widths (0 = default),
+                            -- column headers (each a list of blocks), and
+                            -- rows (each a list of lists of blocks)
     | Null                  -- ^ Nothing
     deriving (Eq, Read, Show, Typeable, Data)
 
diff --git a/src/Text/Pandoc/Readers/Markdown.hs b/src/Text/Pandoc/Readers/Markdown.hs
index 7a16f1578..47a3dbd55 100644
--- a/src/Text/Pandoc/Readers/Markdown.hs
+++ b/src/Text/Pandoc/Readers/Markdown.hs
@@ -761,7 +761,10 @@ tableWith headerParser lineParser footerParser = try $ do
 
 -- Parse a simple table with '---' header and one line per row.
 simpleTable :: GenParser Char ParserState Block
-simpleTable = tableWith simpleTableHeader tableLine blanklines
+simpleTable = do
+  Table c a _w h l <- tableWith simpleTableHeader tableLine blanklines
+  -- Simple tables get 0s for relative column widths (i.e., use default)
+  return $ Table c a (replicate (length a) 0) h l
 
 -- Parse a multiline table:  starts with row of '-' on top, then header
 -- (which may be multiline), then the rows,
diff --git a/src/Text/Pandoc/Writers/ConTeXt.hs b/src/Text/Pandoc/Writers/ConTeXt.hs
index 014751968..25902387b 100644
--- a/src/Text/Pandoc/Writers/ConTeXt.hs
+++ b/src/Text/Pandoc/Writers/ConTeXt.hs
@@ -192,15 +192,16 @@ blockToConTeXt (Header level lst) = do
                          text base <> char '{' <> contents <> char '}'
                     else contents
 blockToConTeXt (Table caption aligns widths heads rows) = do
-    let colWidths = map printDecimal widths
     let colDescriptor colWidth alignment = (case alignment of
                                                AlignLeft    -> 'l' 
                                                AlignRight   -> 'r'
                                                AlignCenter  -> 'c'
                                                AlignDefault -> 'l'):
-                                           "p(" ++ colWidth ++ "\\textwidth)|"
+           if colWidth == 0
+              then "|"
+              else ("p(" ++ printf "%.2f" colWidth ++ "\\textwidth)|")
     let colDescriptors = "|" ++ (concat $ 
-                                 zipWith colDescriptor colWidths aligns)
+                                 zipWith colDescriptor widths aligns)
     headers <- tableRowToConTeXt heads 
     captionText <- inlineListToConTeXt caption 
     let captionText' = if null caption then text "none" else captionText
@@ -210,9 +211,6 @@ blockToConTeXt (Table caption aligns widths heads rows) = do
              text "\\HL" $$ headers $$ text "\\HL" $$
              vcat rows' $$ text "\\HL\n\\stoptable"
 
-printDecimal :: Double  -> String
-printDecimal = printf "%.2f" 
-
 tableRowToConTeXt :: [[Block]] -> State WriterState Doc
 tableRowToConTeXt cols = do
   cols' <- mapM blockListToConTeXt cols
diff --git a/src/Text/Pandoc/Writers/LaTeX.hs b/src/Text/Pandoc/Writers/LaTeX.hs
index a0f9e9004..9a74a069e 100644
--- a/src/Text/Pandoc/Writers/LaTeX.hs
+++ b/src/Text/Pandoc/Writers/LaTeX.hs
@@ -197,17 +197,7 @@ blockToLaTeX (Table caption aligns widths heads rows) = do
   headers <- tableRowToLaTeX heads
   captionText <- inlineListToLaTeX caption
   rows' <- mapM tableRowToLaTeX rows
-  let colWidths = map (printf "%.2f") widths
-  let colDescriptors = concat $ zipWith
-                                (\width align -> ">{\\PBS" ++ 
-                                (case align of 
-                                       AlignLeft -> "\\raggedright"
-                                       AlignRight -> "\\raggedleft"
-                                       AlignCenter -> "\\centering"
-                                       AlignDefault -> "\\raggedright") ++
-                                "\\hspace{0pt}}p{" ++ width ++ 
-                                "\\columnwidth}")
-                                colWidths aligns
+  let colDescriptors = concat $ zipWith toColDescriptor widths aligns
   let tableBody = text ("\\begin{tabular}{" ++ colDescriptors ++ "}") $$
                   headers $$ text "\\hline" $$ vcat rows' $$ 
                   text "\\end{tabular}" 
@@ -221,6 +211,22 @@ blockToLaTeX (Table caption aligns widths heads rows) = do
               else text "\\begin{table}[h]" $$ centered tableBody $$ 
                    inCmd "caption" captionText $$ text "\\end{table}\n" 
 
+toColDescriptor :: Double -> Alignment -> String
+toColDescriptor 0 align =
+  case align of
+         AlignLeft    -> "l"
+         AlignRight   -> "r"
+         AlignCenter  -> "c"
+         AlignDefault -> "l"
+toColDescriptor width align = ">{\\PBS" ++
+  (case align of
+         AlignLeft -> "\\raggedright"
+         AlignRight -> "\\raggedleft"
+         AlignCenter -> "\\centering"
+         AlignDefault -> "\\raggedright") ++
+  "\\hspace{0pt}}p{" ++ printf "%.2f" width ++
+  "\\columnwidth}"
+
 blockListToLaTeX :: [Block] -> State WriterState Doc
 blockListToLaTeX lst = mapM blockToLaTeX lst >>= return . vcat
 
diff --git a/src/Text/Pandoc/Writers/Man.hs b/src/Text/Pandoc/Writers/Man.hs
index 89c865754..616795e31 100644
--- a/src/Text/Pandoc/Writers/Man.hs
+++ b/src/Text/Pandoc/Writers/Man.hs
@@ -171,7 +171,9 @@ blockToMan opts (Table caption alignments widths headers rows) =
   in do
   caption' <- inlineListToMan opts caption
   modify (\(notes, preprocessors) -> (notes, "t":preprocessors))
-  let iwidths = map (printf "w(%0.2fn)" . (70 *)) widths 
+  let iwidths = if all (== 0) widths
+                   then repeat ""
+                   else map (printf "w(%0.2fn)" . (70 *)) widths
   -- 78n default width - 8n indent = 70n
   let coldescriptions = text $ intercalate " "
                         (zipWith (\align width -> aligncode align ++ width) 
diff --git a/src/Text/Pandoc/Writers/Markdown.hs b/src/Text/Pandoc/Writers/Markdown.hs
index a18e1ecd6..d500d4caf 100644
--- a/src/Text/Pandoc/Writers/Markdown.hs
+++ b/src/Text/Pandoc/Writers/Markdown.hs
@@ -34,7 +34,7 @@ import Text.Pandoc.Definition
 import Text.Pandoc.Shared 
 import Text.Pandoc.Blocks
 import Text.ParserCombinators.Parsec ( parse, GenParser )
-import Data.List ( group, isPrefixOf, drop, find, intersperse, intercalate )
+import Data.List ( group, isPrefixOf, drop, find, intersperse, intercalate, transpose )
 import Text.PrettyPrint.HughesPJ hiding ( Str )
 import Control.Monad.State
 
@@ -218,25 +218,29 @@ blockToMarkdown opts (Table caption aligns widths headers rows) =  do
                      then empty
                      else text "" $+$ (text "Table: " <> caption')
   headers' <- mapM (blockListToMarkdown opts) headers
-  let widthsInChars = map (floor . (78 *)) widths
   let alignHeader alignment = case alignment of
                                 AlignLeft    -> leftAlignBlock
                                 AlignCenter  -> centerAlignBlock
                                 AlignRight   -> rightAlignBlock
                                 AlignDefault -> leftAlignBlock  
+  rawRows <- mapM (mapM (blockListToMarkdown opts)) rows
+  let isSimple = all (==0) widths
+  let numChars = maximum . map (length . render)
+  let widthsInChars =
+       if isSimple
+          then map ((+2) . numChars) $ transpose (headers' : rawRows)
+          else map (floor . (78 *)) widths
   let makeRow = hsepBlocks . (zipWith alignHeader aligns) . 
                 (zipWith docToBlock widthsInChars)
   let head' = makeRow headers'
-  rows' <- mapM (\row -> do cols <- mapM (blockListToMarkdown opts) row
-                            return $ makeRow cols) rows
+  let rows' = map makeRow rawRows
   let maxRowHeight = maximum $ map heightOfBlock (head':rows')
-  let isMultilineTable = maxRowHeight > 1
   let underline = hsep $ 
                   map (\width -> text $ replicate width '-') widthsInChars
-  let border = if isMultilineTable
+  let border = if maxRowHeight > 1
                   then text $ replicate (sum widthsInChars + (length widthsInChars - 1)) '-'
                   else empty
-  let spacer = if isMultilineTable
+  let spacer = if maxRowHeight > 1
                   then text ""
                   else empty
   let body = vcat $ intersperse spacer $ map blockToDoc rows'
diff --git a/src/Text/Pandoc/Writers/OpenDocument.hs b/src/Text/Pandoc/Writers/OpenDocument.hs
index 52438f81e..7ef70a0d2 100644
--- a/src/Text/Pandoc/Writers/OpenDocument.hs
+++ b/src/Text/Pandoc/Writers/OpenDocument.hs
@@ -467,13 +467,15 @@ tableStyle num wcs =
         table          = inTags True "style:style"
                          [("style:name", tableId)] $
                          selfClosingTag "style:table-properties"
-                         [ ("style:rel-width", "100%"  )
-                         , ("table:align"    , "center")]
+                         [("table:align"    , "center")]
+        colStyle (c,0) = selfClosingTag "style:style"
+                         [ ("style:name"  , tableId ++ "." ++ [c])
+                         , ("style:family", "table-column"       )]
         colStyle (c,w) = inTags True "style:style"
                          [ ("style:name"  , tableId ++ "." ++ [c])
                          , ("style:family", "table-column"       )] $
                          selfClosingTag "style:table-column-properties"
-                         [("style:column-width", printf "%.2f" (7 * w) ++ "in")]
+                         [("style:rel-column-width", printf "%d*" $ (floor $ w * 65535 :: Integer))]
         cellStyle      = inTags True "style:style"
                          [ ("style:name"  , tableId ++ ".A1")
                          , ("style:family", "table-cell"    )] $
diff --git a/src/Text/Pandoc/Writers/RST.hs b/src/Text/Pandoc/Writers/RST.hs
index 0bff38db7..22d453620 100644
--- a/src/Text/Pandoc/Writers/RST.hs
+++ b/src/Text/Pandoc/Writers/RST.hs
@@ -33,7 +33,7 @@ module Text.Pandoc.Writers.RST ( writeRST) where
 import Text.Pandoc.Definition
 import Text.Pandoc.Shared 
 import Text.Pandoc.Blocks
-import Data.List ( isPrefixOf, isSuffixOf, drop, intersperse )
+import Data.List ( isPrefixOf, isSuffixOf, drop, intersperse, transpose )
 import Text.PrettyPrint.HughesPJ hiding ( Str )
 import Control.Monad.State
 import Control.Applicative ( (<$>) )
@@ -198,7 +198,13 @@ blockToRST (Table caption _ widths headers rows) =  do
                      then empty
                      else text "" $+$ (text "Table: " <> caption')
   headers' <- mapM blockListToRST headers
-  let widthsInChars = map (floor . (78 *)) widths
+  rawRows <- mapM (mapM blockListToRST) rows
+  let isSimple = all (==0) widths && all (all (\bs -> length bs == 1)) rows
+  let numChars = maximum . map (length . render)
+  let widthsInChars =
+       if isSimple
+          then map ((+2) . numChars) $ transpose (headers' : rawRows)
+          else map (floor . (78 *)) widths
   let hpipeBlocks blocks = hcatBlocks [beg, middle, end] 
         where height = maximum (map heightOfBlock blocks)
               sep'   = TextBlock 3 height (replicate height " | ")
diff --git a/src/Text/Pandoc/Writers/RTF.hs b/src/Text/Pandoc/Writers/RTF.hs
index 62d8c4a0c..f8bd0cd2b 100644
--- a/src/Text/Pandoc/Writers/RTF.hs
+++ b/src/Text/Pandoc/Writers/RTF.hs
@@ -191,9 +191,12 @@ blockToRTF indent alignment (Table caption aligns sizes headers rows) =
   rtfPar indent 0 alignment (inlineListToRTF caption)
 
 tableRowToRTF :: Bool -> Int -> [Alignment] -> [Double] -> [[Block]] -> String
-tableRowToRTF header indent aligns sizes cols =
-  let columns = concat $ zipWith (tableItemToRTF indent) aligns cols
-      totalTwips = 6 * 1440 -- 6 inches
+tableRowToRTF header indent aligns sizes' cols =
+  let totalTwips = 6 * 1440 -- 6 inches
+      sizes = if all (== 0) sizes'
+                 then take (length cols) $ repeat (1.0 / fromIntegral (length cols))
+                 else sizes'
+      columns = concat $ zipWith (tableItemToRTF indent) aligns cols
       rightEdges = tail $ scanl (\sofar new -> sofar + floor (new * totalTwips))
                                 (0 :: Integer) sizes
       cellDefs = map (\edge -> (if header
diff --git a/src/Text/Pandoc/Writers/Texinfo.hs b/src/Text/Pandoc/Writers/Texinfo.hs
index 840d64d71..a0986241b 100644
--- a/src/Text/Pandoc/Writers/Texinfo.hs
+++ b/src/Text/Pandoc/Writers/Texinfo.hs
@@ -32,7 +32,8 @@ import Text.Pandoc.Definition
 import Text.Pandoc.Shared
 import Text.Pandoc.Readers.TeXMath
 import Text.Printf ( printf )
-import Data.List ( isSuffixOf )
+import Data.List ( isSuffixOf, transpose, maximumBy )
+import Data.Ord ( comparing )
 import Data.Char ( chr, ord )
 import qualified Data.Set as S
 import Control.Monad.State
@@ -225,9 +226,14 @@ blockToTexinfo (Table caption aligns widths heads rows) = do
   headers <- tableHeadToTexinfo aligns heads
   captionText <- inlineListToTexinfo caption
   rowsText <- mapM (tableRowToTexinfo aligns) rows
-  let colWidths = map (printf "%.2f ") widths
-  let colDescriptors = concat colWidths
-  let tableBody = text ("@multitable @columnfractions " ++ colDescriptors) $$
+  colDescriptors <-
+    if all (== 0) widths
+       then do -- use longest entry instead of column widths
+            cols <- mapM (mapM (liftM (render . hcat) . mapM blockToTexinfo)) $
+                       transpose $ heads : rows
+            return $ concatMap ((\x -> "{"++x++"} ") .  maximumBy (comparing length)) cols
+       else return $ "@columnfractions " ++ concatMap (printf "%.2f ") widths
+  let tableBody = text ("@multitable " ++ colDescriptors) $$
                   headers $$
                   vcat rowsText $$ 
                   text "@end multitable"