Haskell Python
Pull request Compare This branch is 63 commits behind haskell-hvr:master.
Fetching latest commit…
Cannot retrieve the latest commit at this time.
Permalink
Failed to load latest commit information.
Data
benchmarks
examples
tests
.gitignore
.travis.yml
CHANGES.md
LICENSE
README.md
Setup.hs
cabal.project
cassava.cabal

README.md

cassava: A CSV parsing and encoding library

A CSV parsing and encoding library optimized for ease of use and high performance.

Usage example

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"

Further reading

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