summaryrefslogtreecommitdiff
path: root/src/GF/Visualization/Graphviz.hs
blob: a98899b8181d08e34db35d6a22bf183b9eed3f08 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
----------------------------------------------------------------------
-- |
-- Module      : Graphviz
-- Maintainer  : BB
-- Stability   : (stable)
-- Portability : (portable)
--
-- > CVS $Date: 2005/09/15 18:10:44 $ 
-- > CVS $Author: bringert $
-- > CVS $Revision: 1.2 $
--
-- Graphviz DOT format representation and printing.
-----------------------------------------------------------------------------

module GF.Visualization.Graphviz (
				  Graph(..), GraphType(..), 
				  Node(..), Edge(..),
				  Attr,
				  prGraphviz
			) where

import Data.Char

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 ++ " " ++ esc y ++ " " ++ prAttrList at

edgeop :: GraphType -> String
edgeop Directed = "->"
edgeop Undirected = "--"

prAttrList :: [Attr] -> String
prAttrList [] = ""
prAttrList at =	"[" ++ join "," (map prAttr at) ++ "]"

prAttr :: Attr -> String
prAttr (n,v) = esc n ++ " = " ++ esc v

esc :: String -> String
esc s | needEsc s = "\"" ++ concat [ if shouldEsc c then ['\\',c] else [c] | c <- s ] ++ "\""
      | otherwise = s
  where shouldEsc = (`elem` ['"', '\\'])

needEsc :: String -> Bool
needEsc [] = True
needEsc xs | all isDigit xs = False
needEsc (x:xs) = not (isIDFirst x && all isIDChar xs)

isIDFirst, isIDChar :: Char -> Bool
isIDFirst c = c `elem` (['_']++['a'..'z']++['A'..'Z'])
isIDChar c = isIDFirst c || isDigit c