Frames.Dsv

CSV parsers for use with the Frames package.

Most commonly used are dsvTableTypes for generating type definitions at compile time based on a CSV file, and readDsvTable to load the table at run time. These are comparable to tableTypes and readTable from the Frames package, but use an alternative CSV parser.

Row Reading

rowLoop :: Monad m => DsvCursor -> Producer [ByteString] m ()

Produce one DSV row at a time.

dsvRowsByte :: MonadIO m => FilePath -> Word8 -> Producer [ByteString] m ()

Produce rows of raw ByteString values.

dsvRows' :: MonadIO m => FilePath -> Word8 -> Producer [Text] m ()

Produce rows of UTF-8 encoded Text values.

dsvRowsLatin1' :: MonadIO m => FilePath -> Word8 -> Producer [Text] m ()

Produce rows of Latin-1 (aka ISO-8859-1) encoded Text values.

dsvSepErr :: DsvParserOptionsError -> a

Call error indicating the problem with a separator intended for use with the hw-dsv library.

dsvRows :: MonadIO m => FilePath -> Separator -> Producer [Text] m ()

Produce rows of UTF-8 encoded Text values.

dsvRowsLatin1 :: MonadIO m => FilePath -> Separator -> Producer [Text] m ()

Produce rows of Latin-1 (aka ISO-8859-1) encoded Text values.

data DsvParserOptionsError

The ways in which an arbitrary Text value may be unsuitable for use as a separator for the hw-dsv package.

Constructors

SeparatorIsNull

SeparatorCharIsMoreThanOneByte

SeparatorIsMoreThanOneChar

Instances

Eq DsvParserOptionsError

Defined in Frames.Dsv

Methods

(==) :: DsvParserOptionsError -> DsvParserOptionsError -> Bool

(/=) :: DsvParserOptionsError -> DsvParserOptionsError -> Bool

Show DsvParserOptionsError

Defined in Frames.Dsv

Methods

showsPrec :: Int -> DsvParserOptionsError -> ShowS

show :: DsvParserOptionsError -> String

showList :: [DsvParserOptionsError] -> ShowS

separatorWord8 :: Separator -> Either DsvParserOptionsError Word8

The Frames library supports column separators that can be arbitrary Text values, but the hw-dsv library requires a single byte be used to demarcate values. If the given Text can be losslessly represented as a single byte, we sue it, otherwise we return an error indicating the problem.

Whole Table Reading

readDsvTableMaybeOpt :: (MonadIO m, ReadRec rs, RMap rs) => ParserOptions -> FilePath -> Producer (Rec (Maybe :. ElField) rs) m ()

Produce rows where any given entry can fail to parse.

readDsvTableOpt :: (MonadIO m, ReadRec rs, RMap rs) => ParserOptions -> FilePath -> Producer (Record rs) m ()

Returns a producer of rows for which each column was successfully parsed.

readDsvTable :: (MonadIO m, ReadRec rs, RMap rs) => FilePath -> Producer (Record rs) m ()

Returns a producer of rows for which each column was successfully parsed.

Template Haskell

dsvTableTypes :: String -> FilePath -> DecsQ

Like tableType, but additionally generates a type synonym for each column, and a proxy value of that type. If the CSV file has column names "foo", "bar", and "baz", then this will declare type Foo = "foo" :-> Int, for example, foo = rlens @Foo, and foo' = rlens' @Foo.