L.S., Reading and writing a comma seperated datafile doesn't have to be that complicated; the following is an easy way to read a CSV file into a list of tuples and display the list on screen:
displayTuples = do csvData <- readFile "data.csv" putStrLn $ unlines $ map (show . readTuple) $ lines csvData
readTuple :: String -> (Int, Bool, String) readTuple line = read tuple where tuple = '(' : line ++ ")"
If the file "data.csv" contains the following: 1, True, "Festina lente" 2, False, "Carpe diem" displayTuples displays: (1,True,"Festina lente") (2,False,"Carpe diem") Writing a list of tuples to a CSV file is even simpler:
writeTuples file tuples = writeFile file $ unlines $ map (tail . init . show) tuples
The call:
writeTuples "new.csv" [(1, 'a'), (2, 'b')]
results in a file containg:
1,'a'
2,'b'
(without the leading spaces)
Met vriendelijke groet,
Henk-Jan van Tuyl
--
http://Van.Tuyl.eu/
--
On Tue, 22 Aug 2006 11:19:35 +0200, Tamas K Papp
Hi,
Now that I have read the tutorials, I think that the best way to learn Haskell would be to use the language and write something simple yet useful. I noticed that Haskell lacks a module for reading/writing csv (comma separated value) files, so I thought I could implement that.
Questions:
1. Please tell me if you know of a csv module, because then I would do something else.
2. I am looking for a parser, but I don't know Haskell parsers. Is Parsec a good choice?
Thanks,
Tamas
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