1 files changed, 68 insertions, 0 deletions
diff --git a/src/GF/Visualization/Graphviz.hs b/src/GF/Visualization/Graphviz.hs
new file mode 100644
index 000000000..fe2dd0b82
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+++ b/src/GF/Visualization/Graphviz.hs
@@ -0,0 +1,68 @@
+----------------------------------------------------------------------
+-- |
+-- Module      : Graphviz
+-- Maintainer  : BB
+-- Stability   : (stable)
+-- Portability : (portable)
+--
+-- > CVS $Date: 2005/09/14 15:17:30 $ 
+-- > CVS $Author: bringert $
+-- > CVS $Revision: 1.1 $
+--
+-- Graphviz DOT format representation and printing.
+-----------------------------------------------------------------------------
+
+module GF.Visualization.Graphviz (
+				  Graph(..), GraphType(..), 
+				  Node(..), Edge(..),
+				  Attr,
+				  prGraphviz
+			) where
+
+import GF.Data.Utilities
+
+data Graph = Graph GraphType [Attr] [Node] [Edge]
+  deriving (Show)
+
+data GraphType = Directed | Undirected
+  deriving (Show)
+
+data Node = Node String [Attr]
+  deriving Show
+
+data Edge = Edge String String [Attr]
+  deriving Show
+
+type Attr = (String,String)
+
+prGraphviz :: Graph -> String
+prGraphviz (Graph t at ns es) = 
+    unlines $ [graphtype t ++ " {"] 
+		++ map (++";") (map prAttr at
+				++ map prNode ns 
+				++ map (prEdge t) es) 
+		++ ["}\n"]
+
+graphtype :: GraphType -> String
+graphtype Directed = "digraph"
+graphtype Undirected = "graph"
+
+prNode :: Node -> String
+prNode (Node n at) = esc n ++ " " ++ prAttrList at
+
+prEdge :: GraphType -> Edge -> String
+prEdge t (Edge x y at) = esc x ++ " " ++ edgeop t ++ " " ++ prAttrList at
+
+edgeop :: GraphType -> String
+edgeop Directed = "->"
+edgeop Undirected = "--"
+
+prAttrList :: [Attr] -> String
+prAttrList = join "," . map prAttr
+
+prAttr :: Attr -> String
+prAttr (n,v) = esc n ++ " = " ++ esc v
+
+esc :: String -> String
+esc s = "\"" ++ concat [ if shouldEsc c then ['\\',c] else [c] | c <- s ] ++ "\""
+  where shouldEsc = (`elem` ['"', '\\'])
+\ No newline at end of file