enumerator-0.4.19: Reliable, high-performance processing with left-fold enumerators

Portabilityportable
Maintainerjmillikin@gmail.com
Safe HaskellSafe-Infered

Data.Enumerator.Text

Contents

Description

Character-oriented alternatives to Data.Enumerator.List. Note that the enumeratees in this module must unpack their inputs to work properly. If you do not need to handle leftover input on a char-by-char basis, the chunk-oriented versions will be much faster.

This module is intended to be imported qualified: 

 import qualified Data.Enumerator.Text as ET

Since: 0.2

Synopsis

IO

enumHandle :: MonadIO m => Handle -> Enumerator Text m bSource

Read lines of text from a handle, and stream them to an Iteratee. If an exception occurs during file IO, enumeration will stop and Error will be returned. Exceptions from the iteratee are not caught.

The handle should be opened with an appropriate text encoding, and in ReadMode or ReadWriteMode.

This function may be significantly slower than using Data.Enumerator.Binary.enumHandle, due to the additional overhead of decoding input data to Unicode. Users who can depend on their input files being in a certain encoding (such as UTF8) are encouraged to use binary input and decode.

Changed in 0.4.18: Lines streamed from enumHandle and enumFile now include their trailing newline.

Since: 0.2

enumFile :: FilePath -> Enumerator Text IO bSource

Read lines of text from a file, and stream them to an Iteratee. If an exception occurs during file IO, enumeration will stop and Error will be returned. Exceptions from the iteratee are not caught.

The file will be opened in text mode, and will be closed when the Iteratee finishes.

This function may be significantly slower than using Data.Enumerator.Binary.enumFile, due to the additional overhead of decoding input data to Unicode. Users who can depend on their input files being in a certain encoding (such as UTF8) are encouraged to use binary input and decode.

Changed in 0.4.18: Lines streamed from enumHandle and enumFile now include their trailing newline.

Since: 0.2

iterHandle :: MonadIO m => Handle -> Iteratee Text m ()Source

Read text from a stream and write it to a handle. If an exception occurs during file IO, enumeration will stop and Error will be returned.

The handle should be opened with an appropriate text encoding, and in WriteMode or ReadWriteMode.

Since: 0.2

List analogues

Folds

fold :: Monad m => (b -> Char -> b) -> b -> Iteratee Text m bSource

Consume the entire input stream with a strict left fold, one character at a time.

Since: 0.4.8

foldM :: Monad m => (b -> Char -> m b) -> b -> Iteratee Text m bSource

Consume the entire input stream with a strict monadic left fold, one character at a time.

Since: 0.4.8

Maps

map :: Monad m => (Char -> Char) -> Enumeratee Text Text m bSource

map f applies f to each input character and feeds the resulting outputs to the inner iteratee.

Since: 0.4.8

mapM :: Monad m => (Char -> m Char) -> Enumeratee Text Text m bSource

mapM f applies f to each input character and feeds the resulting outputs to the inner iteratee.

Since: 0.4.8

mapM_ :: Monad m => (Char -> m ()) -> Iteratee Text m ()Source

mapM_ f applies f to each input character, and discards the results.

Since: 0.4.11

concatMap :: Monad m => (Char -> Text) -> Enumeratee Text Text m bSource

concatMap f applies f to each input character and feeds the resulting outputs to the inner iteratee.

Since: 0.4.8

concatMapM :: Monad m => (Char -> m Text) -> Enumeratee Text Text m bSource

concatMapM f applies f to each input character and feeds the resulting outputs to the inner iteratee.

Since: 0.4.8

Accumulating maps

mapAccum :: Monad m => (s -> Char -> (s, Char)) -> s -> Enumeratee Text Text m bSource

Similar to map, but with a stateful step function.

Since: 0.4.9

mapAccumM :: Monad m => (s -> Char -> m (s, Char)) -> s -> Enumeratee Text Text m bSource

Similar to mapM, but with a stateful step function.

Since: 0.4.9

concatMapAccum :: Monad m => (s -> Char -> (s, Text)) -> s -> Enumeratee Text Text m bSource

Similar to concatMap, but with a stateful step function.

Since: 0.4.11

concatMapAccumM :: Monad m => (s -> Char -> m (s, Text)) -> s -> Enumeratee Text Text m bSource

Similar to concatMapM, but with a stateful step function.

Since: 0.4.11

Infinite streams

iterate :: Monad m => (Char -> Char) -> Char -> Enumerator Text m bSource

iterate f x enumerates an infinite stream of repeated applications of f to x.

Analogous to iterate.

Since: 0.4.8

iterateM :: Monad m => (Char -> m Char) -> Char -> Enumerator Text m bSource

Similar to iterate, except the iteration function is monadic.

Since: 0.4.8

repeat :: Monad m => Char -> Enumerator Text m bSource

Enumerates an infinite stream of a single character.

Analogous to repeat.

Since: 0.4.8

repeatM :: Monad m => m Char -> Enumerator Text m bSource

Enumerates an infinite stream of characters. Each character is computed by the underlying monad.

Since: 0.4.8

Bounded streams

replicate :: Monad m => Integer -> Char -> Enumerator Text m bSource

replicate n x enumerates a stream containing n copies of x.

Since: 0.4.8

replicateM :: Monad m => Integer -> m Char -> Enumerator Text m bSource

replicateM n m_x enumerates a stream of n characters, with each character computed by m_x.

Since: 0.4.8

generateM :: Monad m => m (Maybe Char) -> Enumerator Text m bSource

Like repeatM, except the computation may terminate the stream by returning Nothing.

Since: 0.4.8

unfold :: Monad m => (s -> Maybe (Char, s)) -> s -> Enumerator Text m bSource

Enumerates a stream of characters by repeatedly applying a function to some state.

Similar to iterate.

Since: 0.4.8

unfoldM :: Monad m => (s -> m (Maybe (Char, s))) -> s -> Enumerator Text m bSource

Enumerates a stream of characters by repeatedly applying a computation to some state.

Similar to iterateM.

Since: 0.4.8

Dropping input

drop :: Monad m => Integer -> Iteratee Text m ()Source

drop n ignores n characters of input from the stream.

Since: 0.4.5

dropWhile :: Monad m => (Char -> Bool) -> Iteratee Text m ()Source

dropWhile p ignores input from the stream until the first character which does not match the predicate.

Since: 0.4.5

filter :: Monad m => (Char -> Bool) -> Enumeratee Text Text m bSource

Applies a predicate to the stream. The inner iteratee only receives characters for which the predicate is True.

Since: 0.4.8

filterM :: Monad m => (Char -> m Bool) -> Enumeratee Text Text m bSource

Applies a monadic predicate to the stream. The inner iteratee only receives characters for which the predicate returns True.

Since: 0.4.8

Consumers

head :: Monad m => Iteratee Text m (Maybe Char)Source

Get the next character from the stream, or Nothing if the stream has ended.

Since: 0.4.5

head_ :: Monad m => Iteratee Text m CharSource

Get the next element from the stream, or raise an error if the stream has ended.

Since: 0.4.14

take :: Monad m => Integer -> Iteratee Text m TextSource

take n extracts the next n characters from the stream, as a lazy Text.

Since: 0.4.5

takeWhile :: Monad m => (Char -> Bool) -> Iteratee Text m TextSource

takeWhile p extracts input from the stream until the first character which does not match the predicate.

Since: 0.4.5

consume :: Monad m => Iteratee Text m TextSource

consume = takeWhile (const True)

Since: 0.4.5

Zipping

zip :: Monad m => Iteratee Text m b1 -> Iteratee Text m b2 -> Iteratee Text m (b1, b2)Source

Pass input from a stream through two iteratees at once. Excess input is yielded if it was not consumed by either iteratee.

Analogous to zip.

Since: 0.4.14

zip3 :: Monad m => Iteratee Text m b1 -> Iteratee Text m b2 -> Iteratee Text m b3 -> Iteratee Text m (b1, b2, b3)Source

Pass input from a stream through three iteratees at once. Excess input is yielded if it was not consumed by any iteratee.

Analogous to zip3.

Since: 0.4.14

zip4 :: Monad m => Iteratee Text m b1 -> Iteratee Text m b2 -> Iteratee Text m b3 -> Iteratee Text m b4 -> Iteratee Text m (b1, b2, b3, b4)Source

Pass input from a stream through four iteratees at once. Excess input is yielded if it was not consumed by any iteratee.

Analogous to zip4.

Since: 0.4.14

zip5 :: Monad m => Iteratee Text m b1 -> Iteratee Text m b2 -> Iteratee Text m b3 -> Iteratee Text m b4 -> Iteratee Text m b5 -> Iteratee Text m (b1, b2, b3, b4, b5)Source

Pass input from a stream through five iteratees at once. Excess input is yielded if it was not consumed by any iteratee.

Analogous to zip5.

Since: 0.4.14

zip6 :: Monad m => Iteratee Text m b1 -> Iteratee Text m b2 -> Iteratee Text m b3 -> Iteratee Text m b4 -> Iteratee Text m b5 -> Iteratee Text m b6 -> Iteratee Text m (b1, b2, b3, b4, b5, b6)Source

Pass input from a stream through six iteratees at once. Excess input is yielded if it was not consumed by any iteratee.

Analogous to zip6.

Since: 0.4.14

zip7 :: Monad m => Iteratee Text m b1 -> Iteratee Text m b2 -> Iteratee Text m b3 -> Iteratee Text m b4 -> Iteratee Text m b5 -> Iteratee Text m b6 -> Iteratee Text m b7 -> Iteratee Text m (b1, b2, b3, b4, b5, b6, b7)Source

Pass input from a stream through seven iteratees at once. Excess input is yielded if it was not consumed by any iteratee.

Analogous to zip7.

Since: 0.4.14

zipWith :: Monad m => (b1 -> b2 -> c) -> Iteratee Text m b1 -> Iteratee Text m b2 -> Iteratee Text m cSource

Pass input from a stream through two iteratees at once. Excess input is yielded if it was not consumed by either iteratee. Output from the iteratees is combined with a user-provided function.

Analogous to zipWith.

Since: 0.4.14

zipWith3 :: Monad m => (b1 -> b2 -> b3 -> c) -> Iteratee Text m b1 -> Iteratee Text m b2 -> Iteratee Text m b3 -> Iteratee Text m cSource

Pass input from a stream through two iteratees at once. Excess input is yielded if it was not consumed by either iteratee. Output from the iteratees is combined with a user-provided function.

Analogous to zipWith3.

Since: 0.4.14

zipWith4 :: Monad m => (b1 -> b2 -> b3 -> b4 -> c) -> Iteratee Text m b1 -> Iteratee Text m b2 -> Iteratee Text m b3 -> Iteratee Text m b4 -> Iteratee Text m cSource

Pass input from a stream through two iteratees at once. Excess input is yielded if it was not consumed by either iteratee. Output from the iteratees is combined with a user-provided function.

Analogous to zipWith4.

Since: 0.4.14

zipWith5 :: Monad m => (b1 -> b2 -> b3 -> b4 -> b5 -> c) -> Iteratee Text m b1 -> Iteratee Text m b2 -> Iteratee Text m b3 -> Iteratee Text m b4 -> Iteratee Text m b5 -> Iteratee Text m cSource

Pass input from a stream through two iteratees at once. Excess input is yielded if it was not consumed by either iteratee. Output from the iteratees is combined with a user-provided function.

Analogous to zipWith5.

Since: 0.4.14

zipWith6 :: Monad m => (b1 -> b2 -> b3 -> b4 -> b5 -> b6 -> c) -> Iteratee Text m b1 -> Iteratee Text m b2 -> Iteratee Text m b3 -> Iteratee Text m b4 -> Iteratee Text m b5 -> Iteratee Text m b6 -> Iteratee Text m cSource

Pass input from a stream through two iteratees at once. Excess input is yielded if it was not consumed by either iteratee. Output from the iteratees is combined with a user-provided function.

Analogous to zipWith6.

Since: 0.4.14

zipWith7 :: Monad m => (b1 -> b2 -> b3 -> b4 -> b5 -> b6 -> b7 -> c) -> Iteratee Text m b1 -> Iteratee Text m b2 -> Iteratee Text m b3 -> Iteratee Text m b4 -> Iteratee Text m b5 -> Iteratee Text m b6 -> Iteratee Text m b7 -> Iteratee Text m cSource

Pass input from a stream through two iteratees at once. Excess input is yielded if it was not consumed by either iteratee. Output from the iteratees is combined with a user-provided function.

Analogous to zipWith7.

Since: 0.4.14

Unsorted

require :: Monad m => Integer -> Iteratee Text m ()Source

require n buffers input until at least n characters are available, or throws an error if the stream ends early.

Since: 0.4.5

isolate :: Monad m => Integer -> Enumeratee Text Text m bSource

isolate n reads at most n characters from the stream, and passes them to its iteratee. If the iteratee finishes early, characters continue to be consumed from the outer stream until n have been consumed.

Since: 0.4.5

isolateWhile :: Monad m => (Char -> Bool) -> Enumeratee Text Text m bSource

isolateWhile p reads characters from the stream until p is false, and passes them to its iteratee. If the iteratee finishes early, characters continue to be consumed from the outer stream until p is false.

Since: 0.4.16

splitWhen :: Monad m => (Char -> Bool) -> Enumeratee Text Text m bSource

Split on characters satisfying a given predicate.

Since: 0.4.8

lines :: Monad m => Enumeratee Text Text m bSource

lines = splitWhen (== '\n')

Since: 0.4.8

Text codecs

data Codec Source

Instances

encode :: Monad m => Codec -> Enumeratee Text ByteString m bSource

Convert text into bytes, using the provided codec. If the codec is not capable of representing an input character, an error will be thrown.

Since: 0.2

decode :: Monad m => Codec -> Enumeratee ByteString Text m bSource

Convert bytes into text, using the provided codec. If the codec is not capable of decoding an input byte sequence, an error will be thrown.

Since: 0.2

utf8 :: CodecSource

utf16_le :: CodecSource

utf16_be :: CodecSource

utf32_le :: CodecSource

utf32_be :: CodecSource

ascii :: CodecSource

iso8859_1 :: CodecSource