Please refer to the package description for an overview of cassava.
Here's the two second crash course in using the library. Given a CSV file with this content:
John Doe,50000 Jane Doe,60000 here's how you'd process it record-by-record:
{-# LANGUAGE ScopedTypeVariables #-} import qualified Data.ByteString.Lazy as BL import Data.Csv import qualified Data.Vector as V main :: IO () main = do csvData <- BL.readFile "salaries.csv" case decode NoHeader csvData of Left err -> putStrLn err Right v -> V.forM_ v $ \ (name, salary :: Int) -> putStrLn $ name ++ " earns " ++ show salary ++ " dollars"If you want to parse a file that includes a header, like this one
name,salary John Doe,50000 Jane Doe,60000 use decodeByName:
{-# LANGUAGE OverloadedStrings #-} import Control.Applicative import qualified Data.ByteString.Lazy as BL import Data.Csv import qualified Data.Vector as V data Person = Person { name :: !String , salary :: !Int } instance FromNamedRecord Person where parseNamedRecord r = Person <$> r .: "name" <*> r .: "salary" main :: IO () main = do csvData <- BL.readFile "salaries.csv" case decodeByName csvData of Left err -> putStrLn err Right (_, v) -> V.forM_ v $ \ p -> putStrLn $ name p ++ " earns " ++ show (salary p) ++ " dollars"You can find more code examples in the examples/ folder as well as smaller usage examples in the Data.Csv module documentation.
There's no end to what people consider CSV data. Most programs don't follow RFC4180 so one has to make a judgment call which contributions to accept. Consequently, not everything gets accepted, because then we'd end up with a (slow) general purpose parsing library. There are plenty of those. The goal is to roughly accept what the Python csv module accepts.
The Python csv module (which is implemented in C) is also considered the base-line for performance. Adding options (e.g. the above mentioned parsing "flexibility") will have to be a trade off against performance. There's been complaints about performance in the past, therefore, if in doubt performance wins over features.
Last but not least, it's important to keep the dependency footprint light, as each additional dependency incurs costs and risks in terms of additional maintenance overhead and loss of flexibility. So adding a new package dependency should only be done if that dependency is known to be a reliable package and there's a clear benefit which outweights the cost.
The primary API documentation for cassava is its Haddock documentation which can be found at http://hackage.haskell.org/package/cassava/docs/Data-Csv.html
Below are listed additional recommended third-party blogposts and tutorials