diff options
Diffstat (limited to 'src/Grasp')
-rw-r--r-- | src/Grasp/Parser.hs | 92 |
1 files changed, 77 insertions, 15 deletions
diff --git a/src/Grasp/Parser.hs b/src/Grasp/Parser.hs index 7b4f685..0e6f8e3 100644 --- a/src/Grasp/Parser.hs +++ b/src/Grasp/Parser.hs @@ -216,40 +216,102 @@ stmtList (n,e) = try (node >>= (\x -> stmtList (x:n,e)) ) <|> try (edge >>= (\x -> stmtList (n,x:e)) ) <|> try (attr >> stmtList (n,e)) - <|> try (subgraph >>= (\(x,y) -> stmtList (x ++ n, y ++ e)) ) + <|> try (subgraph >>= (\(x,y) -> stmtList ((reverse x) ++ n, (reverse y) ++ e)) ) <|> return (reverse n, reverse e) --- todo -alphaNumString = return "a" +alphaNumString = do + a <- nonDigitChar + b <- many alphaNumChar + return (a:b) --- todo -numeral = return "0" +nonDigitChar = letter <|> char '_' +alphaNumChar = alphaNum <|> char '_' --- todo -quotedString = return "\"" +numeral = try negativeNum <|> positiveNum +negativeNum = char '-' >> positiveNum >>= return . ('-':) +positiveNum = try pointNum <|> try floatNum <|> wholeNum +pointNum = char '.' >> some digit >>= return . ('.':) +wholeNum = some digit +floatNum = do { a <- some digit; char '.'; b <- many digit; return (a ++ "." ++ b)} --- todo -node = return ("1","a") +quotedString = do + char '\"' + s <- some quotedChar + char '\"' + return s + + +quotedChar = noneOf "\"\r\n" <|> try (char '\\' >> char '\"') + + +node = do + n <- ident + a <- attrList + return (n,a) + + +edge = do + a <- ident + edgeOp + b <- ident + c <- attrList + return (a,b,c) + + +edgeOp = string "->" --- todo -edge = return ("1","2","b") +attr = attrType >> attrList +attrType = caseInsensitiveString "graph" + <|> caseInsensitiveString "node" + <|> caseInsensitiveString "edge" --- todo -attr = return "" +attrList = do + a <- many aList + let r = filter (\x -> fst x == "label") (concat a) + case (length r) of + 0 -> fail "expected node/edge label" + 1 -> return . snd . head $ r + _ -> fail "unexpected multiple labels for single node/edge" --- todo -subgraph = return ([],[]) +aList = do + openBracket + a <- many equAttr + closeBracket + return a + + +equAttr = do + e <- equ + optional (char ';' <|> char ',') + return e + + +equ = do + a <- ident + char '=' + b <- ident + return (a,b) + + +subgraph = do + optional (caseInsensitiveString "subgraph" >> optional ident) + openBrace + (n,e) <- stmtList ([],[]) + closeBrace + return (n,e) openBrace = char '{' closeBrace = char '}' +openBracket = char '[' +closeBracket = char ']' caseInsensitiveChar c = char (toLower c) <|> char (toUpper c) |