gistfile1.lhs

paquetes :: IO [String]
paquetes = readFile "packages.log" >>= (\k -> return $ lines k) >>= (\k -> return $ map  (takeWhile (/= ' ')) k)

flechas :: IO [String]
flechas = readFile "portgraph.dot"  >>= (\k -> return $ lines k) >>= (\k -> return $ init $ tail k)

-- "foo-1.2.3" -> "bar-baz-2.0.0" 
-- se convierte en (foo, bar-baz)
-- se considera que no hay paquetes con subcadena "-<num>" en el nombre
flecha_a_par :: String -> (String, String)
flecha_a_par xs = (quita_version a, quita_version b) where
    izq = takeWhile (/= '>') xs
    der = dropWhile (/= '>') xs
    a = takeWhile (/= '"') $ tail $ dropWhile (/= '"') izq
    b = takeWhile (/= '"') $ tail $ dropWhile (/= '"') der
    quita_version (x:'-':num:xs) 
        | elem num ['0'..'9'] = [x]
        | otherwise = x:'-': num : quita_version xs
    quita_version (x:xs) = x : quita_version xs

encadenar = do
    p <- paquetes
    f <- flechas
    let pares = map flecha_a_par f
    let filtrado = filter (\(a,b) -> elem a p && elem b p) pares
    let res = map (\(a,b) -> show a ++ " -> " ++ show b) filtrado
    return $ unlines res

-- encadenar >>= (\k -> writeFile "dependencias.dot" k)