Safe Haskell	Safe-Infered

Data.CSV.Conduit

Contents

Convenience Functions

Synopsis

Documentation

class CSVeable s r whereSource

Represents types r that can be converted from an underlying stream of type s.

Example processing using MapRow Text isntance:

 test :: IO ()
 test = runResourceT $ 
   sourceFile test/BigFile.csv $= 
   decode utf8 $=
   intoCSV defCSVSettings $=
   myMapRowProcessingConduit $=
   fromCSV defCSVSettings $=
   encode utf8 $$
   sinkFile test/BigFileOut.csv

Methods

rowToStr :: CSVSettings -> r -> sSource

Convert a CSV row into strict ByteString equivalent.

intoCSV :: MonadResource m => CSVSettings -> Conduit s m rSource

Turn a stream of s into a stream of CSV row type

fromCSV :: MonadResource m => CSVSettings -> Conduit r m sSource

Turn a stream of CSV row type back into a stream of s

Instances

(CSVeable s (Row s'), Ord s', IsString s) => CSVeable s (MapRow s')	Generic `MapRow` instance; any stream type with a `Row` instance automatically gets a `MapRow` instance.
CSVeable ByteString (Row ByteString)	`Row` instance using `ByteString`
CSVeable ByteString (Row Text)	`Row` instance using `Text` based on `ByteString` stream
CSVeable Text (Row Text)	`Row` instance using `Text`

data CSVSettings Source

Settings for a CSV file. This library is intended to be flexible and offer a way to process the majority of text data files out there.

Constructors

CSVS

Fields

csvSep :: !Char: Separator character to be used in between fields
csvQuoteChar :: !(Maybe Char): Quote character that may sometimes be present around fields. If Nothing is given, the library will never expect quotation even if it is present.
csvOutputQuoteChar :: !(Maybe Char): Quote character that should be used in the output.
csvOutputColSep :: !Char: Field separator that should be used in the output.

Instances

Eq CSVSettings
Read CSVSettings
Show CSVSettings

defCSVSettings :: CSVSettings Source

Default settings for a CSV file.

 csvSep = ','
 csvQuoteChar = Just '"'
 csvOutputQuoteChar = Just '"'
 csvOutputColSep = ','

type MapRow a = Map a aSource

A MapRow is a dictionary based on Map

type Row a = [a]Source

A Row is just a list of fields

Convenience Functions

readCSVFile :: (MonadUnsafeIO m, MonadThrow m, MonadBaseControl IO m, MonadIO m, CSVeable ByteString a) => CSVSettings -> FilePath -> m [a]Source

Read the entire contents of a CSV file into memory

mapCSVFile Source

Arguments

:: (MonadIO m, MonadUnsafeIO m, MonadThrow m, MonadBaseControl IO m, CSVeable ByteString a, CSVeable ByteString b)
=> CSVSettings	Settings to use both for input and output
-> (a -> b)	A mapping function
-> FilePath	Input file
-> FilePath	Output file
-> m ()

Map over the rows of a CSV file. Don't be scared by the type signature, this can just run in IO.