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
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
|
module Grasp.Parser (
GraspProgram(..),
parseGrasp,
) where
import Control.Applicative( some )
import Text.ParserCombinators.Parsec
import Text.ParserCombinators.Parsec.Error
import Text.Parsec.Pos
import Data.Graph.Inductive.Graph( Node, LNode, LEdge, (&) )
import Data.Graph.Inductive.Graph as Graph
import Data.Graph.Inductive.Tree
type GraspProgram = Gr String String
parseGrasp :: String -> Either ParseError GraspProgram
parseGrasp input = parse grasp "error" input >>= validate
validate :: ([LNode String],[LEdge String]) -> Either ParseError GraspProgram
validate (nodeList, edgeList) =
let nameEdges = filter (\(_,_,z) -> z == "name") edgeList
nameNodes = map (\(_,x,_) -> x) nameEdges
nameLNodes = filter (\(x,_) -> x `elem` nameNodes) nodeList
a = multiNames nameEdges
b = nonStringNames nameLNodes
c = noGraspMain nameLNodes
in case (a,b,c) of
([],[],False) -> Right (Graph.mkGraph nodeList edgeList)
([],[],True) -> Left (newErrorMessage (Message "could not find grasp:main") (newPos "" 0 0))
([],(x:_),_) -> Left (newErrorMessage (Message ("node " ++ (show x) ++ " has a numeric name")) (newPos "" 0 0))
((x:_),_,_) -> Left (newErrorMessage (Message ("node " ++ (show x) ++ " has multiple names")) (newPos "" 0 0))
multiNames :: [LEdge String] -> [LNode String]
multiNames x = []
nonStringNames :: [LNode String] -> [LNode String]
nonStringNames x = []
noGraspMain :: [LNode String] -> Bool
noGraspMain x = False
grasp = do
string "digraph {"
whiteSpace
(n,e) <- stmtList ([],[])
string "}"
eol
eof
return (n,e)
stmtList (n,e) =
try (node >>= (\x -> stmtList (x:n,e)) )
<|> try (edge >>= (\x -> stmtList (n,x:e)) )
<|> return (reverse n, reverse e)
node = do
i <- ident
l <- labelAttrib
whiteSpace
return (i,l)
edge = do
a <- ident
directedEdge
b <- ident
l <- labelAttrib
whiteSpace
return (a,b,l)
ident = do
d <- some digit
inLineWhSp
return (read d)
labelAttrib = do
char '['
inLineWhSp
string "label=\""
l <- labelID
char '\"'
inLineWhSp
string "];"
return l
labelID = some (noneOf "\"\r\n\\" <|> escapedChar)
escapedChar = try (string "\\\"" >> return '\"')
<|> try (string "\\\\" >> return '\\')
directedEdge = string "->" >> inLineWhSp
inLineWhSp = many (oneOf "\t ")
whiteSpace = many (oneOf "\n\r\t ")
eol = try (string "\r\n")
<|> try (string "\n\r")
<|> try (string "\n")
<|> try (string "\r")
<?> "end of line"
|