11 Apr
2011
11 Apr
'11
3:30 a.m.
On Mon, 11 Apr 2011, Mitar wrote:
generateGraph :: Int -> IO (Gr String Double) generateGraph graphSize = do when (graphSize < 1) $ throwIO $ AssertionFailed $ "Graph size out of bounds " ++ show graphSize let ns = map (\n -> (n, show n)) [1..graphSize] es <- fmap concat $ forM [1..graphSize] $ \node -> do nedges <- randomRIO (0, graphSize) others <- fmap (filter (node /=) . nub) $ forM [1..nedges] $ \_ -> randomRIO (1, graphSize) gen <- getStdGen let weights = randomRs (1, 10) gen return $ zip3 (repeat node) others weights return $ mkGraph ns es
Just a note on style: This function can perfectly be written without IO. http://www.haskell.org/haskellwiki/Avoiding_IO#State_monad