first incarnation of the bracketed string API

1 files changed, 270 insertions, 313 deletions

diff --git a/src/runtime/haskell/PGF/VisualizeTree.hs b/src/runtime/haskell/PGF/VisualizeTree.hs
index e58791d4d..3075e7a86 100644
--- a/src/runtime/haskell/PGF/VisualizeTree.hs
+++ b/src/runtime/haskell/PGF/VisualizeTree.hs
@@ -15,339 +15,296 @@
 --        instead of rolling its own.
 -----------------------------------------------------------------------------
 
-module PGF.VisualizeTree ( graphvizAbstractTree
-                         , graphvizParseTree
-                         , graphvizDependencyTree
-                         , graphvizAlignment
-                         , tree2mk
-                         , getDepLabels
-                         , PosText(..), readPosText
+module PGF.VisualizeTree 
+             ( graphvizAbstractTree
+             , graphvizParseTree
+             , graphvizDependencyTree
+             , graphvizBracketedString
+             , graphvizAlignment
+             , getDepLabels
 			 ) where
 
-import PGF.CId (CId,showCId,pCId,mkCId)
+import PGF.CId (CId,showCId,ppCId,mkCId)
 import PGF.Data
-import PGF.Tree
-import PGF.Expr (showExpr)
+import PGF.Expr (showExpr, Tree)
 import PGF.Linearize
-import PGF.Macros (lookValCat)
+import PGF.Macros (lookValCat, BracketedString(..), flattenBracketedString)
 
 import qualified Data.Map as Map
 import Data.List (intersperse,nub,isPrefixOf,sort,sortBy)
 import Data.Char (isDigit)
-import qualified Text.ParserCombinators.ReadP as RP
-
-import Debug.Trace
-
-graphvizAbstractTree :: PGF -> (Bool,Bool) -> Expr -> String
-graphvizAbstractTree pgf funscats = prGraph False . tree2graph pgf funscats . expr2tree
-
-tree2graph :: PGF -> (Bool,Bool) -> Tree -> [String]
-tree2graph pgf (funs,cats) = prf [] where
-  prf ps t = let (nod,lab) = prn ps t in 
-    (nod ++ " [label = " ++ lab ++ ", style = \"solid\", shape = \"plaintext\"] ;") : 
-    case t of
-      Fun cid trees -> 
-        [       pra (j:ps) nod t | (j,t) <- zip [0..] trees] ++
-        concat [prf (j:ps) t     | (j,t) <- zip [0..] trees]
-      Abs xs (Fun cid trees) -> 
-        [       pra (j:ps) nod t | (j,t) <- zip [0..] trees] ++
-        concat [prf (j:ps) t     | (j,t) <- zip [0..] trees]
-      _ -> []
-  prn ps t = case t of
-    Fun cid _ ->
-      let
-        fun = if funs then showCId cid else ""
-        cat = if cats then prCat cid else ""
-        colon = if funs && cats then " : " else ""
-        lab = "\"" ++ fun ++ colon ++ cat ++ "\""
-      in (show(show (ps :: [Int])),lab)
-    Abs bs tree -> 
-      let fun = case tree of
-            Fun cid _ -> Fun cid []
-            _ -> tree
-      in (show(show (ps :: [Int])),"\"" ++ esc (prTree (Abs bs fun)) ++ "\"")
-    _ -> (show(show (ps :: [Int])),"\"" ++ esc (prTree t) ++ "\"")
-  pra i nod t = nod ++ arr ++ fst (prn i t) ++ " [style = \"solid\"];"
-  arr = " -- " -- if digr then " -> " else " -- "
-  prCat = showCId . lookValCat pgf
-  esc = concatMap (\c -> if c =='\\' then [c,c] else [c]) --- escape backslash in abstracts
-
-prGraph digr ns = concat $ map (++"\n") $ [graph ++ "{\n"] ++ ns ++ ["}"] where
-  graph = if digr then "digraph" else "graph"
-
-
--- replace each non-atomic constructor with mkC, where C is the val cat
-tree2mk :: PGF -> Expr -> String
-tree2mk pgf = showExpr [] . tree2expr . t2m . expr2tree where
-  t2m t = case t of
-    Fun cid [] -> t
-    Fun cid ts -> Fun (mk cid) (map t2m ts)
-    _ -> t
-  mk = mkCId . ("mk" ++) . showCId . lookValCat pgf
-
--- dependency trees from Linearize.linearizeMark
-
-graphvizDependencyTree :: String -> Bool -> Maybe Labels -> Maybe String -> PGF -> CId -> Expr -> String
-graphvizDependencyTree format debug mlab ms pgf lang exp = case format of
-  "malt" -> unlines (lin2dep format)
-  "malt_input" -> unlines (lin2dep format)
-  _ -> prGraph True (lin2dep format) 
-
- where
-
-  lin2dep format = -- trace (ifd (show sortedNodes ++ show nodeWords)) $ 
-    case format of
-      "malt" -> map (concat . intersperse "\t") wnodes
-      "malt_input" -> map (concat . intersperse "\t" . take 6) wnodes
-      _ -> prelude ++ nodes ++ links
-
-  ifd s = if debug then s else []
-
-  pot = readPosText $ concat $ take 1 $ markLinearizes pgf lang exp
-  ---- use Just str if you have str to match against
-
-  prelude = ["rankdir=LR ;", "node [shape = plaintext] ;"]
-
-  nodes = map mkNode nodeWords
-  mkNode (i,((_,p),ss)) = 
-    node p ++ " [label = \"" ++ show i ++ ". " ++ ifd (show p) ++ unwords ss ++ "\"] ;"
-  nodeWords = (0,((mkCId "",[]),["ROOT"])) : zip [1..] [((f,p),w)| 
-                                       ((Just f,p),w) <- wlins pot]
-
-  links = map mkLink thelinks 
-  thelinks =  [(word y, x, label tr y x) | 
-                      (_,((f,x),_)) <- tail nodeWords,
-                      let y = dominant x]
-  mkLink (x,y,l) = node x ++ " -> " ++ node y ++ " [label = \"" ++ l ++ "\"] ;"
-  node = show . show
-
-  dominant x = case x of 
-    [] -> x
-    _ | not (x == hx) -> hx
-    _  -> dominant (init x)
-   where
-    hx = headArg (init x) tr x
-
-  headArg x0 tr x = case (tr,x) of
-    (Fun f [],[_]) -> x0 ---- ??
-    (Fun f ts,[_]) -> x0 ++ [getHead (length ts - 1) f]
-    (Fun f ts,i:y) -> headArg x0 (ts !! i) y
-    _ -> x0 ----
-
-  label tr y x = case span (uncurry (==)) (zip y x) of
-    (xys,(_,i):_) -> getLabel i (funAt tr (map fst xys))
-    _ -> "" ----
-
-  funAt tr x = case (tr,x) of
-    (Fun f _ ,[])  -> f
-    (Fun f ts,i:y) -> funAt (ts !! i) y
-    _ -> mkCId (prTree tr) ----
-
-  word x = if elem x sortedNodes then x else 
-           let x' = headArg x tr (x ++[0]) in
-           if x' == x then [] else word x'
-
-  tr = expr2tree exp
-  sortedNodes = [p | (_,((_,p),_)) <- nodeWords]
-
-  labels = maybe Map.empty id mlab
-  getHead i f = case Map.lookup f labels of
-    Just ls -> length $ takeWhile (/= "head") ls
-    _ -> i
-  getLabel i f = case Map.lookup f labels of
-    Just ls | length ls > i -> ifd (showCId f ++ "#" ++ show i ++ "=") ++ ls !! i
-    _ -> showCId f ++ "#" ++ show i
-
--- to generate CoNLL format for MaltParser
-  nodeMap :: Map.Map [Int] Int
-  nodeMap = Map.fromList [(p,i) | (i,((_,p),_)) <- nodeWords]
-
-  arcMap :: Map.Map [Int] ([Int],String)
-  arcMap = Map.fromList [(y,(x,l)) | (x,y,l) <- thelinks]
-
-  lookDomLab p = case Map.lookup p arcMap of
-    Just (q,l) -> (maybe 0 id (Map.lookup q nodeMap), if null l then rootlabel else l)
-    _          -> (0,rootlabel)
-
-  wnodes = [[show i, maltws ws, showCId fun, pos, pos, morph, show dom, lab, unspec, unspec] | 
-              (i, ((fun,p),ws)) <- tail nodeWords,
-              let pos = showCId $ lookValCat pgf fun,
-              let morph = unspec,
-              let (dom,lab) = lookDomLab p
-           ]
-  maltws = concat . intersperse "+" . words . unwords  -- no spaces in column 2
-  unspec = "_"
-  rootlabel = "ROOT"
-
-type Labels = Map.Map CId [String]
-
-getDepLabels :: [String] -> Labels
-getDepLabels ss = Map.fromList [(mkCId f,ls) | f:ls <- map words ss]
+import Text.PrettyPrint
+
+-- | Renders abstract syntax tree in Graphviz format
+graphvizAbstractTree :: PGF -> (Bool,Bool) -> Tree -> String
+graphvizAbstractTree pgf (funs,cats) = render . tree2graph
+  where
+    tree2graph t =
+      text "graph {" $$
+      ppGraph [] [] 0 t $$
+      text "}"
+
+    getAbs xs (EAbs _ x e) = getAbs (x:xs) e
+    getAbs xs (ETyped e _) = getAbs xs e
+    getAbs xs e            = (xs,e)
+    
+    getApp (EApp x y)   es = getApp x (y:es)
+    getApp (ETyped e _) es = getApp e es
+    getApp e            es = (e,es)
+
+    getLbl scope (EFun f)     = let fun = if funs then ppCId f else empty
+                                    cat = if cats then ppCId (lookValCat pgf f) else empty
+                                    sep = if funs && cats then colon else empty
+                                in fun <+> sep <+> cat
+    getLbl scope (ELit l)     = text (escapeStr (render (ppLit l)))
+    getLbl scope (EMeta i)    = ppMeta i
+    getLbl scope (EVar i)     = ppCId (scope !! i)
+    getLbl scope (ETyped e _) = getLbl scope e
+    getLbl scope (EImplArg e) = getLbl scope e
+
+    ppGraph scope ps i e0 =
+      let (xs,  e1) = getAbs [] e0
+          (e2,args) = getApp e1 []
+          binds     = if null xs
+                        then empty
+                        else text "\\\\" <> hcat (punctuate comma (map ppCId xs)) <+> text "->"
+          (lbl,eargs) = case e2 of
+                          EAbs _ _ _ -> (char '@', e2:args) -- eta-redexes are rendered with artificial "@" node
+                          _          -> (getLbl scope' e2, args)
+          scope'    = xs ++ scope
+      in ppNode (i:ps) <> text "[label =" <+> doubleQuotes (binds <+> lbl) <> text ", style = \"solid\", shape = \"plaintext\"] ;" $$
+         (if null ps
+            then empty
+            else ppNode ps <+> text "--" <+> ppNode (i:ps) <+> text "[style = \"solid\"];") $$
+         vcat (zipWith (ppGraph scope' (i:ps)) [0..] eargs)
+
+    ppNode ps = char 'n' <> hcat (punctuate (char '_') (map int ps))
+    
+    escapeStr []        = []
+    escapeStr ('\\':cs) = '\\':'\\':escapeStr cs
+    escapeStr ('"' :cs) = '\\':'"' :escapeStr cs
+    escapeStr (c   :cs) = c        :escapeStr cs    
 
 
--- parse trees from Linearize.linearizeMark
----- nubrec and domins are quadratic, but could be (n log n)
-
-graphvizParseTree :: PGF -> CId -> Expr -> String
-graphvizParseTree pgf lang = prGraph False . lin2tree pgf . concat . take 1 . markLinearizes pgf lang where
-
-lin2tree pgf s = prelude ++ nodes ++ links where
+type Labels = Map.Map CId [String]
 
-  prelude = ["rankdir=BU ;", "node [shape = record, color = white] ;"]
+graphvizDependencyTree :: String -> Bool -> Maybe Labels -> Maybe String -> PGF -> CId -> Tree -> String
+graphvizDependencyTree format debug mlab ms pgf lang t = render $
+  case format of
+    "malt"       -> vcat (map (hcat . intersperse (char '\t')         ) wnodes)
+    "malt_input" -> vcat (map (hcat . intersperse (char '\t') . take 6) wnodes)
+    _            -> text "digraph {" $$
+                    space $$
+                    nest 2 (text "rankdir=LR ;" $$
+                            text "node [shape = plaintext] ;" $$
+                            vcat nodes $$
+                            links) $$
+                    text "}"
+  where
+    nodes  = map mkNode leaves
+    links  = empty
+    wnodes = undefined
+
+    nil = -1
+
+    bs = bracketedLinearize pgf lang t
+
+    leaves = (nil,0,"ROOT") : (groupAndIndexIt 1 . getLeaves nil) bs
+
+    groupAndIndexIt id []          = []
+    groupAndIndexIt id ((p,w):pws) = let (ws,pws1) = collect pws
+                                     in (p,id,unwords (w:ws)) : groupAndIndexIt (id+1) pws1
+      where
+        collect pws@((p1,w):pws1)
+          | p == p1   = let (ws,pws2) = collect pws1
+                        in (w:ws,pws2)
+        collect pws   = ([],pws)
+
+    getLeaves parent bs =
+      case bs of
+        Leaf w              -> [(parent,w)]
+        Bracket fid _ _ bss -> concatMap (getLeaves fid) bss
+
+    mkNode (p,i,w) = 
+      tag p <> text " [label = " <> doubleQuotes (int i <> char '.' <+> text w) <> text "] ;"
 
-  nodeRecs = zip [0..] 
-    (nub (filter (not . null) (nlins [postext] ++ [leaves postext])))
-  nlins pts = 
-    nubrec [] $ [(p,cat f) | T (Just f, p) _ <- pts] : 
-                   concatMap nlins [ts | T _ ts <- pts]  
-  leaves pt = [(p++[j],s) | (j,(p,s)) <- 
-                zip [9990..] [(p,s) | ((_,p),ss) <- wlins pt, s <- ss]]
+{-
+    ifd s = if debug then s else []
+
+    pot = readPosText $ concat $ take 1 $ markLinearizes pgf lang exp
+
+    nodes = map mkNode nodeWords
+    mkNode (i,((_,p),ss)) = 
+      node p ++ " [label = \"" ++ show i ++ ". " ++ ifd (show p) ++ unwords ss ++ "\"] ;"
+    nodeWords = (0,((mkCId "",[]),["ROOT"])) : zip [1..] [((f,p),w)| 
+                                         ((Just f,p),w) <- wlins pot]
+
+    links = map mkLink thelinks 
+    thelinks =  [(word y, x, label tr y x) | 
+                        (_,((f,x),_)) <- tail nodeWords,
+                        let y = dominant x]
+    mkLink (x,y,l) = node x ++ " -> " ++ node y ++ " [label = \"" ++ l ++ "\"] ;"
+    node = show . show
+
+    dominant x = case x of 
+      [] -> x
+      _ | not (x == hx) -> hx
+      _  -> dominant (init x)
+     where
+      hx = headArg (init x) tr x
+
+    headArg x0 tr x = case (tr,x) of
+      (Fun f [],[_]) -> x0 ---- ??
+      (Fun f ts,[_]) -> x0 ++ [getHead (length ts - 1) f]
+      (Fun f ts,i:y) -> headArg x0 (ts !! i) y
+      _ -> x0 ----
+
+    label tr y x = case span (uncurry (==)) (zip y x) of
+      (xys,(_,i):_) -> getLabel i (funAt tr (map fst xys))
+      _ -> "" ----
+
+    funAt tr x = case (tr,x) of
+      (Fun f _ ,[])  -> f
+      (Fun f ts,i:y) -> funAt (ts !! i) y
+      _ -> mkCId (prTree tr) ----
+
+    word x = if elem x sortedNodes then x else 
+             let x' = headArg x tr (x ++[0]) in
+             if x' == x then [] else word x'
+
+    tr = expr2tree exp
+    sortedNodes = [p | (_,((_,p),_)) <- nodeWords]
+
+    labels = maybe Map.empty id mlab
+    getHead i f = case Map.lookup f labels of
+      Just ls -> length $ takeWhile (/= "head") ls
+      _ -> i
+    getLabel i f = case Map.lookup f labels of
+      Just ls | length ls > i -> ifd (showCId f ++ "#" ++ show i ++ "=") ++ ls !! i
+      _ -> showCId f ++ "#" ++ show i
+
+  -- to generate CoNLL format for MaltParser
+    nodeMap :: Map.Map [Int] Int
+    nodeMap = Map.fromList [(p,i) | (i,((_,p),_)) <- nodeWords]
+
+    arcMap :: Map.Map [Int] ([Int],String)
+    arcMap = Map.fromList [(y,(x,l)) | (x,y,l) <- thelinks]
+
+    lookDomLab p = case Map.lookup p arcMap of
+      Just (q,l) -> (maybe 0 id (Map.lookup q nodeMap), if null l then rootlabel else l)
+      _          -> (0,rootlabel)
+
+    wnodes = [[show i, maltws ws, showCId fun, pos, pos, morph, show dom, lab, unspec, unspec] | 
+                (i, ((fun,p),ws)) <- tail nodeWords,
+                let pos = showCId $ lookValCat pgf fun,
+                let morph = unspec,
+                let (dom,lab) = lookDomLab p
+             ]
+    maltws = concat . intersperse "+" . words . unwords  -- no spaces in column 2
+    unspec = "_"
+    rootlabel = "ROOT"
+-}
 
-  nubrec es rs = case rs of
-    r:rr -> let r' = filter (not . flip elem es) (nub r) 
-            in r' : nubrec (r' ++ es) rr
-    _ -> rs
 
-  nodes = map mkStruct nodeRecs
+getDepLabels :: [String] -> Labels
+getDepLabels ss = Map.fromList [(mkCId f,ls) | f:ls <- map words ss]
 
-  mkStruct (i,cs) = struct i ++ "[label = \"" ++ fields cs ++ "\"] ;"
-  cat = showCId . lookValCat pgf
-  fields cs = concat (intersperse "|" [ mtag (showp p) ++ c | (p,c) <- cs])
-  struct i = "struct" ++ show i
 
-  links = map mkEdge domins
-  domins = nub [((i,x),(j,y)) | 
-    (i,xs) <- nodeRecs, (j,ys) <- nodeRecs, 
-    x <- xs, y <- ys, dominates x y]
-  dominates (p,x) (q,y) = not (null q) && p == init q
-  mkEdge ((i,x),(j,y)) = 
-    struct i ++ ":n" ++ uncommas (showp (fst x)) ++ ":s -- " ++ 
-    struct j ++ ":n" ++ uncommas (showp (fst y)) ++ ":n ;"
+graphvizParseTree :: PGF -> Language -> Tree -> String
+graphvizParseTree pgf lang = graphvizBracketedString . bracketedLinearize pgf lang
+
+graphvizBracketedString :: BracketedString -> String
+graphvizBracketedString = render . lin2tree
+  where
+    lin2tree bs =
+      text "graph {" $$
+      space $$
+      nest 2 (text "rankdir=BU ;" $$
+              text "node [shape = record, color = white] ;" $$
+              space $$
+              vcat (nodes bs)) $$
+      text "}"
+      where
+        nodes bs = zipWith mkStruct [0..] (interns ++ [zipWith (\i (l,p,w) -> (l,p,i,w)) [99990..] leaves])
+
+        nil = -1
+        
+        leaves  = getLeaves  0 nil bs
+        interns = getInterns 0 [(nil,bs)]
+
+        getLeaves  level parent bs =
+          case bs of
+            Leaf w              -> [(level-1,parent,w)]
+            Bracket fid i _ bss -> concatMap (getLeaves (level+1) fid) bss
+
+        getInterns level []    = []
+        getInterns level nodes =
+          nub [(level-1,parent,fid,showCId cat) | (parent,Bracket fid _ cat _) <- nodes] :
+          getInterns (level+1) [(fid,child) | (_,Bracket fid _ _ children) <- nodes, child <- children]
+
+        mkStruct l cs = struct l <> text "[label = \"" <> fields cs <> text "\"] ;" $$
+                        vcat [link pl pid l id | (pl,pid,id,_) <- cs]
+        link pl pid l id
+          | pl < 0    = empty
+          | otherwise = struct pl <> colon <> tag pid <> colon <> char 's' <+>
+                        text "--" <+>
+                        struct l  <> colon <> tag  id <> colon <> char 'n' <+> semi
+        fields cs = hsep (intersperse (char '|') [tbrackets (tag id) <> text c | (_,_,id,c) <- cs])
 
-  postext = readPosText s
 
 -- auxiliaries for graphviz syntax
-struct i = "struct" ++ show i
-mark (j,n) = "n" ++ show j ++ "a" ++ uncommas n
-uncommas = map (\c -> if c==',' then 'c' else c)
-tag s = "<" ++ s ++ ">"
-showp = init . tail . show
-mtag = tag . ('n':) . uncommas
+struct l = text ("struct" ++ show l)
+tbrackets d = char '<' <> d  <> char '>'
+tag i = char 'n' <> int i
 
 -- word alignments from Linearize.markLinearize
 -- words are chunks like {[0,1,1,0] old}
 
-graphvizAlignment :: PGF -> Expr -> String
-graphvizAlignment pgf = prGraph True . lin2graph . linsMark  where
-  linsMark t = [concat (take 1 (markLinearizes pgf la t)) | la <- Map.keys (concretes pgf)]
-
-lin2graph :: [String] -> [String]
-lin2graph ss = -- trace (show ss) $ 
-               prelude ++ nodes ++ links
-
- where
-
-  prelude = ["rankdir=LR ;", "node [shape = record] ;"]
-
-  nlins :: [(Int,[((Int,String),String)])]
-  nlins = [(i, [((j,showp p),unw ws) | (j,((_,p),ws)) <- zip [0..] ws]) | 
-                                (i,ws) <- zip [0..] (map (wlins . readPosText) ss)]
-
-  unw = concat . intersperse "\\ "  -- space escape in graphviz
-
-  nodes = map mkStruct nlins
-
-  mkStruct (i, ws) = struct i ++ "[label = \"" ++ fields ws ++ "\"] ;"
-
-  fields ws = concat (intersperse "|" [tag (mark m) ++ " " ++ w | (m,w) <- ws]) 
-
-  links = nub $ concatMap mkEdge (init nlins)
-
-  mkEdge (i,lin) = let lin' = snd (nlins !! (i+1)) in -- next lin in the list
-    [edge i v w | (v@(_,p),_) <- lin, (w@(_,q),_) <- lin', p == q]
-
-  edge i v w = 
-    struct i ++ ":" ++ mark v ++ ":e -> " ++ struct (i+1) ++ ":" ++ mark w ++ ":w ;"
-{-
-alignmentData :: PGF -> [Expr] -> Map.Map String (Map.Map String Double)
-alignmentData pgf = mkStat . concatMap (mkAlign . linsMark)  where
-  linsMark t = 
-    [s | la <- take 2 (cncnames pgf), s <- take 1 (linearizesMark pgf la t)]
-
-  mkStat :: [(String,String)] -> Map.Map String (Map.Map String Double)
-  mkStat = 
-
-  mkAlign :: [String] -> [(String,String)]
-  mkAlign ss = 
-
-  nlins :: [(Int,[((Int,String),String)])]
-  nlins = [(i, [((j,showp p),unw ws) | (j,((_,p),ws)) <- zip [0..] vs]) | 
-                                (i,vs) <- zip [0..] (map (wlins . readPosText) ss)]
-
-  nodes = map mkStruct nlins
-
-  mkStruct (i, ws) = struct i ++ "[label = \"" ++ fields ws ++ "\"] ;"
-
-  fields ws = concat (intersperse "|" [tag (mark m) ++ " " ++ w | (m,w) <- ws]) 
-
-  links = nub $ concatMap mkEdge (init nlins)
-
-  mkEdge (i,lin) = let lin' = snd (nlins !! (i+1)) in -- next lin in the list
-    [edge i v w | (v@(_,p),_) <- lin, (w@(_,q),_) <- lin', p == q]
-
-  edge i v w = 
-    struct i ++ ":" ++ mark v ++ ":e -> " ++ struct (i+1) ++ ":" ++ mark w ++ ":w ;"
--}
-
-wlins :: PosText -> [((Maybe CId,[Int]),[String])]
-wlins pt = case pt of
-  T p pts -> concatMap (lins p) pts
-  M ws -> if null ws then [] else [((Nothing,[]),ws)]
- where
-  lins p pt = case pt of
-    T q pts -> concatMap (lins q) pts
-    M ws -> if null ws then [] else [(p,ws)]
-
-data PosText = 
-   T (Maybe CId,[Int]) [PosText]
- | M [String]
-  deriving Show
-
-readPosText :: String -> PosText
-readPosText = fst . head . (RP.readP_to_S pPosText) where
-  pPosText = do
-    RP.char '(' >> RP.skipSpaces
-    p  <- pPos  
-    RP.skipSpaces
-    ts <- RP.many pPosText
-    RP.char ')' >> RP.skipSpaces
-    return (T p ts)
-   RP.<++ do
-    ws <- RP.sepBy1 (RP.munch1 (flip notElem "()")) (RP.char ' ') 
-    return (M ws) 
-  pPos = do
-    fun <- (RP.char '(' >> pCId >>= \f -> RP.char ',' >> (return $ Just f)) 
-           RP.<++ (return Nothing)
-    RP.char '[' >> RP.skipSpaces
-    is <- RP.sepBy (RP.munch1 isDigit) (RP.char ',')
-    RP.char ']' >> RP.skipSpaces
-    RP.char ')' RP.<++ return ' ' 
-    return (fun,map read is)
-
-
-{-
-digraph{
-rankdir ="LR" ;
-node [shape = record] ;
-
-struct1 [label = "<f0> this|<f1> very|<f2> intelligent|<f3> man"] ;
-struct2 [label = "<f0> cet|<f1> homme|<f2> tres|<f3> intelligent|<f4> ci"] ;
-
-struct1:f0 -> struct2:f0 ;
-struct1:f1 -> struct2:f2 ;
-struct1:f2 -> struct2:f3 ;
-struct1:f3 -> struct2:f1 ;
-struct1:f0 -> struct2:f4 ;
-}
--}
-
+graphvizAlignment :: PGF -> [Language] -> Expr -> String
+graphvizAlignment pgf langs = render . lin2graph . linsBracketed
+  where
+    linsBracketed t = [bracketedLinearize pgf lang t | lang <- langs]
+
+    lin2graph :: [BracketedString] -> Doc
+    lin2graph bss =
+      text "digraph {" $$
+      space $$
+      nest 2 (text "rankdir=LR ;" $$
+              text "node [shape = record] ;" $$
+              space $$
+              mkLayers 0 leaves) $$
+      text "}"
+      where
+        nil = -1
+
+        leaves = map (groupAndIndexIt 0 . getLeaves nil) bss
+
+        groupAndIndexIt id []          = []
+        groupAndIndexIt id ((p,w):pws) = let (ws,pws1) = collect pws
+                                         in (p,id,unwords (w:ws)) : groupAndIndexIt (id+1) pws1
+          where
+            collect pws@((p1,w):pws1)
+              | p == p1   = let (ws,pws2) = collect pws1
+                            in (w:ws,pws2)
+            collect pws   = ([],pws)
+
+        getLeaves parent bs =
+          case bs of
+            Leaf w              -> [(parent,w)]
+            Bracket fid _ _ bss -> concatMap (getLeaves fid) bss
+
+        mkLayers l []       = empty
+        mkLayers l (cs:css) = struct l <> text "[label = \"" <> fields cs <> text "\"] ;" $$
+                              (case css of
+                                 (ncs:_) -> vcat (map (mkLinks l ncs) cs)
+                                 _       -> empty)  $$
+                              mkLayers (l+1) css
+
+        mkLinks l cs (p0,id0,_) = 
+          vcat (map (\id1 -> struct l     <> colon <> tag id0 <> colon <> char 'e' <+>
+                             text "->" <+>
+                             struct (l+1) <> colon <> tag id1 <> colon <> char 'w' <+> semi) indices)
+          where
+            indices = [id1 | (p1,id1,_) <- cs, p1 == p0]
+
+        fields cs = hsep (intersperse (char '|') [tbrackets (tag id) <> text w | (_,id,w) <- cs])