tree visualization command

src-3.0/PGF/VisualizeTree.hs

@@ -0,0 +1,42 @@
+----------------------------------------------------------------------
+-- |
+-- Module      : VisualizeTree
+-- Maintainer  : AR
+-- Stability   : (stable)
+-- Portability : (portable)
+--
+-- > CVS $Date: 
+-- > CVS $Author:
+-- > CVS $Revision: 
+--
+-- Print a graph of an abstract syntax tree in Graphviz DOT format
+-- Based on BB's VisualizeGrammar
+-- FIXME: change this to use GF.Visualization.Graphviz, 
+--        instead of rolling its own.
+-----------------------------------------------------------------------------
+
+module PGF.VisualizeTree ( visualizeTrees
+			) where
+
+import PGF.CId (prCId)
+import PGF.Data
+
+visualizeTrees :: Bool -> [Tree] -> String
+visualizeTrees digr = unlines . map (prGraph digr . tree2graph digr)
+
+tree2graph :: Bool -> Tree -> [String]
+tree2graph digr = prf [] where
+  prf ps t = case t of
+    Fun cid trees -> 
+      let (nod,lab) = prn ps cid in
+        (nod ++ " [label = " ++ lab ++ ", style = \"solid\", shape = \"plaintext\"] ;") : 
+        [       pra (j:ps) nod t | (j,t) <- zip [0..] trees] ++
+        concat [prf (j:ps) t     | (j,t) <- zip [0..] trees]
+  prn ps cid = 
+    let lab = "\"" ++ prCId cid ++ "\""
+    in (show(show (ps :: [Int])),lab)
+  pra i nod t@(Fun cid _) =  nod ++ arr ++ fst (prn i cid) ++ " [style = \"solid\"];"
+  arr = if digr then " -> " else " -- "
+
+prGraph digr ns = concat $ map (++"\n") $ [graph ++ "{\n"] ++ ns ++ ["}"] where
+  graph = if digr then "digraph" else "graph"