| Safe Haskell | None |
|---|---|
| Language | Haskell2010 |
RIO.ByteString.Lazy
Description
Lazy ByteString. Import as:
import qualified RIO.ByteString.Lazy as BL
This module does not export any partial functions. For those, see RIO.ByteString.Lazy.Partial
Synopsis
- data ByteString
- empty :: ByteString
- singleton :: Word8 -> ByteString
- pack :: [Word8] -> ByteString
- unpack :: ByteString -> [Word8]
- fromStrict :: StrictByteString -> LazyByteString
- toStrict :: LazyByteString -> StrictByteString
- fromChunks :: [StrictByteString] -> LazyByteString
- toChunks :: LazyByteString -> [StrictByteString]
- foldrChunks :: (StrictByteString -> a -> a) -> a -> ByteString -> a
- foldlChunks :: (a -> StrictByteString -> a) -> a -> ByteString -> a
- cons :: Word8 -> ByteString -> ByteString
- cons' :: Word8 -> ByteString -> ByteString
- snoc :: ByteString -> Word8 -> ByteString
- append :: ByteString -> ByteString -> ByteString
- uncons :: ByteString -> Maybe (Word8, ByteString)
- unsnoc :: ByteString -> Maybe (ByteString, Word8)
- null :: ByteString -> Bool
- length :: ByteString -> Int64
- map :: (Word8 -> Word8) -> ByteString -> ByteString
- reverse :: ByteString -> ByteString
- intersperse :: Word8 -> ByteString -> ByteString
- intercalate :: ByteString -> [ByteString] -> ByteString
- transpose :: [ByteString] -> [ByteString]
- foldl :: (a -> Word8 -> a) -> a -> ByteString -> a
- foldl' :: (a -> Word8 -> a) -> a -> ByteString -> a
- foldr :: (Word8 -> a -> a) -> a -> ByteString -> a
- concat :: [ByteString] -> ByteString
- concatMap :: (Word8 -> ByteString) -> ByteString -> ByteString
- any :: (Word8 -> Bool) -> ByteString -> Bool
- all :: (Word8 -> Bool) -> ByteString -> Bool
- scanl :: (Word8 -> Word8 -> Word8) -> Word8 -> ByteString -> ByteString
- mapAccumL :: (acc -> Word8 -> (acc, Word8)) -> acc -> ByteString -> (acc, ByteString)
- mapAccumR :: (acc -> Word8 -> (acc, Word8)) -> acc -> ByteString -> (acc, ByteString)
- repeat :: Word8 -> ByteString
- replicate :: Int64 -> Word8 -> ByteString
- cycle :: HasCallStack => ByteString -> ByteString
- iterate :: (Word8 -> Word8) -> Word8 -> ByteString
- unfoldr :: (a -> Maybe (Word8, a)) -> a -> ByteString
- take :: Int64 -> ByteString -> ByteString
- drop :: Int64 -> ByteString -> ByteString
- splitAt :: Int64 -> ByteString -> (ByteString, ByteString)
- takeWhile :: (Word8 -> Bool) -> ByteString -> ByteString
- dropWhile :: (Word8 -> Bool) -> ByteString -> ByteString
- span :: (Word8 -> Bool) -> ByteString -> (ByteString, ByteString)
- break :: (Word8 -> Bool) -> ByteString -> (ByteString, ByteString)
- group :: ByteString -> [ByteString]
- groupBy :: (Word8 -> Word8 -> Bool) -> ByteString -> [ByteString]
- inits :: ByteString -> [ByteString]
- tails :: ByteString -> [ByteString]
- stripPrefix :: ByteString -> ByteString -> Maybe ByteString
- stripSuffix :: ByteString -> ByteString -> Maybe ByteString
- split :: Word8 -> ByteString -> [ByteString]
- splitWith :: (Word8 -> Bool) -> ByteString -> [ByteString]
- isPrefixOf :: ByteString -> ByteString -> Bool
- isSuffixOf :: ByteString -> ByteString -> Bool
- elem :: Word8 -> ByteString -> Bool
- notElem :: Word8 -> ByteString -> Bool
- find :: (Word8 -> Bool) -> ByteString -> Maybe Word8
- filter :: (Word8 -> Bool) -> ByteString -> ByteString
- partition :: (Word8 -> Bool) -> ByteString -> (ByteString, ByteString)
- index :: HasCallStack => ByteString -> Int64 -> Word8
- elemIndex :: Word8 -> ByteString -> Maybe Int64
- elemIndexEnd :: Word8 -> ByteString -> Maybe Int64
- elemIndices :: Word8 -> ByteString -> [Int64]
- findIndex :: (Word8 -> Bool) -> ByteString -> Maybe Int64
- findIndices :: (Word8 -> Bool) -> ByteString -> [Int64]
- count :: Word8 -> ByteString -> Int64
- zip :: ByteString -> ByteString -> [(Word8, Word8)]
- zipWith :: (Word8 -> Word8 -> a) -> ByteString -> ByteString -> [a]
- unzip :: [(Word8, Word8)] -> (ByteString, ByteString)
- copy :: ByteString -> ByteString
- getContents :: MonadIO m => m LByteString
- putStr :: MonadIO m => LByteString -> m ()
- putStrLn :: MonadIO m => LByteString -> m ()
- interact :: MonadIO m => (LByteString -> LByteString) -> m ()
- readFile :: MonadIO m => FilePath -> m LByteString
- writeFile :: MonadIO m => FilePath -> LByteString -> m ()
- appendFile :: MonadIO m => FilePath -> LByteString -> m ()
- hGetContents :: MonadIO m => Handle -> m LByteString
- hGet :: MonadIO m => Handle -> Int -> m LByteString
- hGetNonBlocking :: MonadIO m => Handle -> Int -> m LByteString
- hPut :: MonadIO m => Handle -> LByteString -> m ()
- hPutNonBlocking :: MonadIO m => Handle -> LByteString -> m LByteString
- hPutStr :: MonadIO m => Handle -> LByteString -> m ()
The ByteString type
data ByteString #
A space-efficient representation of a Word8 vector, supporting many
efficient operations.
A LazyByteString contains 8-bit bytes, or by using the operations
from Data.ByteString.Lazy.Char8 it can be interpreted as containing
8-bit characters.
Instances
Introducing and eliminating ByteStrings
empty :: ByteString #
O(1) The empty ByteString
singleton :: Word8 -> ByteString #
O(1) Convert a Word8 into a ByteString
pack :: [Word8] -> ByteString #
O(n) Convert a '[Word8]' into a ByteString.
unpack :: ByteString -> [Word8] #
O(n) Converts a ByteString to a '[Word8]'.
fromStrict :: StrictByteString -> LazyByteString #
O(1) Convert a StrictByteString into a LazyByteString.
toStrict :: LazyByteString -> StrictByteString #
O(n) Convert a LazyByteString into a StrictByteString.
Note that this is an expensive operation that forces the whole
LazyByteString into memory and then copies all the data. If possible, try to
avoid converting back and forth between strict and lazy bytestrings.
fromChunks :: [StrictByteString] -> LazyByteString #
O(c) Convert a list of StrictByteString into a LazyByteString
toChunks :: LazyByteString -> [StrictByteString] #
O(c) Convert a LazyByteString into a list of StrictByteString
foldrChunks :: (StrictByteString -> a -> a) -> a -> ByteString -> a #
Consume the chunks of a lazy ByteString with a natural right fold.
foldlChunks :: (a -> StrictByteString -> a) -> a -> ByteString -> a #
Consume the chunks of a lazy ByteString with a strict, tail-recursive, accumulating left fold.
Basic interface
cons :: Word8 -> ByteString -> ByteString infixr 5 #
cons' :: Word8 -> ByteString -> ByteString infixr 5 #
O(1) Unlike cons, cons' is
strict in the ByteString that we are consing onto. More precisely, it forces
the head and the first chunk. It does this because, for space efficiency, it
may coalesce the new byte onto the first 'chunk' rather than starting a
new 'chunk'.
So that means you can't use a lazy recursive contruction like this:
let xs = cons' c xs in xs
You can however use cons, as well as repeat and cycle, to build
infinite lazy ByteStrings.
snoc :: ByteString -> Word8 -> ByteString infixl 5 #
O(n/c) Append a byte to the end of a ByteString
append :: ByteString -> ByteString -> ByteString #
O(n/c) Append two ByteStrings
uncons :: ByteString -> Maybe (Word8, ByteString) #
unsnoc :: ByteString -> Maybe (ByteString, Word8) #
null :: ByteString -> Bool #
O(1) Test whether a ByteString is empty.
Transforming ByteStrings
map :: (Word8 -> Word8) -> ByteString -> ByteString #
O(n) map f xs is the ByteString obtained by applying f to each
element of xs.
reverse :: ByteString -> ByteString #
O(n) reverse xs returns the elements of xs in reverse order.
intersperse :: Word8 -> ByteString -> ByteString #
The intersperse function takes a Word8 and a ByteString and
`intersperses' that byte between the elements of the ByteString.
It is analogous to the intersperse function on Lists.
intercalate :: ByteString -> [ByteString] -> ByteString #
O(n) The intercalate function takes a ByteString and a list of
ByteStrings and concatenates the list after interspersing the first
argument between each element of the list.
transpose :: [ByteString] -> [ByteString] #
The transpose function transposes the rows and columns of its
ByteString argument.
Reducing ByteStrings (folds)
foldl :: (a -> Word8 -> a) -> a -> ByteString -> a #
foldl, applied to a binary operator, a starting value (typically
the left-identity of the operator), and a ByteString, reduces the
ByteString using the binary operator, from left to right.
foldl' :: (a -> Word8 -> a) -> a -> ByteString -> a #
foldr :: (Word8 -> a -> a) -> a -> ByteString -> a #
foldr, applied to a binary operator, a starting value
(typically the right-identity of the operator), and a ByteString,
reduces the ByteString using the binary operator, from right to left.
Special folds
concat :: [ByteString] -> ByteString #
O(n) Concatenate a list of ByteStrings.
concatMap :: (Word8 -> ByteString) -> ByteString -> ByteString #
Map a function over a ByteString and concatenate the results
any :: (Word8 -> Bool) -> ByteString -> Bool #
O(n) Applied to a predicate and a ByteString, any determines if
any element of the ByteString satisfies the predicate.
all :: (Word8 -> Bool) -> ByteString -> Bool #
O(n) Applied to a predicate and a ByteString, all determines
if all elements of the ByteString satisfy the predicate.
Building ByteStrings
Scans
Arguments
| :: (Word8 -> Word8 -> Word8) | accumulator -> element -> new accumulator |
| -> Word8 | starting value of accumulator |
| -> ByteString | input of length n |
| -> ByteString | output of length n+1 |
Accumulating maps
mapAccumL :: (acc -> Word8 -> (acc, Word8)) -> acc -> ByteString -> (acc, ByteString) #
mapAccumR :: (acc -> Word8 -> (acc, Word8)) -> acc -> ByteString -> (acc, ByteString) #
Infinite ByteStrings
repeat :: Word8 -> ByteString #
is an infinite ByteString, with repeat xx the value of every
element.
replicate :: Int64 -> Word8 -> ByteString #
O(n) is a ByteString of length replicate n xn with x
the value of every element.
cycle :: HasCallStack => ByteString -> ByteString #
cycle ties a finite ByteString into a circular one, or equivalently,
the infinite repetition of the original ByteString.
iterate :: (Word8 -> Word8) -> Word8 -> ByteString #
returns an infinite ByteString of repeated applications
of iterate f xf to x:
iterate f x == [x, f x, f (f x), ...]
Unfolding ByteStrings
unfoldr :: (a -> Maybe (Word8, a)) -> a -> ByteString #
O(n) The unfoldr function is analogous to the List 'unfoldr'.
unfoldr builds a ByteString from a seed value. The function takes
the element and returns Nothing if it is done producing the
ByteString or returns Just (a,b), in which case, a is a
prepending to the ByteString and b is used as the next element in a
recursive call.
Substrings
Breaking strings
take :: Int64 -> ByteString -> ByteString #
drop :: Int64 -> ByteString -> ByteString #
splitAt :: Int64 -> ByteString -> (ByteString, ByteString) #
takeWhile :: (Word8 -> Bool) -> ByteString -> ByteString #
Similar to takeWhile,
returns the longest (possibly empty) prefix of elements
satisfying the predicate.
dropWhile :: (Word8 -> Bool) -> ByteString -> ByteString #
Similar to dropWhile,
drops the longest (possibly empty) prefix of elements
satisfying the predicate and returns the remainder.
span :: (Word8 -> Bool) -> ByteString -> (ByteString, ByteString) #
break :: (Word8 -> Bool) -> ByteString -> (ByteString, ByteString) #
group :: ByteString -> [ByteString] #
The group function takes a ByteString and returns a list of
ByteStrings such that the concatenation of the result is equal to the
argument. Moreover, each string in the result contains only equal
elements. For example,
group "Mississippi" = ["M","i","ss","i","ss","i","pp","i"]
It is a special case of groupBy, which allows the programmer to
supply their own equality test.
groupBy :: (Word8 -> Word8 -> Bool) -> ByteString -> [ByteString] #
inits :: ByteString -> [ByteString] #
Returns all initial segments of the given ByteString, shortest first.
tails :: ByteString -> [ByteString] #
O(n) Returns all final segments of the given ByteString, longest first.
stripPrefix :: ByteString -> ByteString -> Maybe ByteString #
O(n) The stripPrefix function takes two ByteStrings and returns Just
the remainder of the second iff the first is its prefix, and otherwise
Nothing.
Since: bytestring-0.10.8.0
stripSuffix :: ByteString -> ByteString -> Maybe ByteString #
O(n) The stripSuffix function takes two ByteStrings and returns Just
the remainder of the second iff the first is its suffix, and otherwise
Nothing.
Breaking into many substrings
split :: Word8 -> ByteString -> [ByteString] #
O(n) Break a ByteString into pieces separated by the byte
argument, consuming the delimiter. I.e.
split 10 "a\nb\nd\ne" == ["a","b","d","e"] -- fromEnum '\n' == 10 split 97 "aXaXaXa" == ["","X","X","X",""] -- fromEnum 'a' == 97 split 120 "x" == ["",""] -- fromEnum 'x' == 120 split undefined "" == [] -- and not [""]
and
intercalate [c] . split c == id split == splitWith . (==)
As for all splitting functions in this library, this function does
not copy the substrings, it just constructs new ByteStrings that
are slices of the original.
splitWith :: (Word8 -> Bool) -> ByteString -> [ByteString] #
O(n) Splits a ByteString into components delimited by
separators, where the predicate returns True for a separator element.
The resulting components do not contain the separators. Two adjacent
separators result in an empty component in the output. eg.
splitWith (==97) "aabbaca" == ["","","bb","c",""] -- fromEnum 'a' == 97 splitWith undefined "" == [] -- and not [""]
Predicates
isPrefixOf :: ByteString -> ByteString -> Bool #
O(n) The isPrefixOf function takes two ByteStrings and returns True
iff the first is a prefix of the second.
isSuffixOf :: ByteString -> ByteString -> Bool #
O(n) The isSuffixOf function takes two ByteStrings and returns True
iff the first is a suffix of the second.
The following holds:
isSuffixOf x y == reverse x `isPrefixOf` reverse y
Search ByteStrings
Searching by equality
elem :: Word8 -> ByteString -> Bool #
O(n) elem is the ByteString membership predicate.
Searching with a predicate
filter :: (Word8 -> Bool) -> ByteString -> ByteString #
O(n) filter, applied to a predicate and a ByteString,
returns a ByteString containing those characters that satisfy the
predicate.
partition :: (Word8 -> Bool) -> ByteString -> (ByteString, ByteString) #
O(n) The partition function takes a predicate a ByteString and returns
the pair of ByteStrings with elements which do and do not satisfy the
predicate, respectively; i.e.,
partition p bs == (filter p xs, filter (not . p) xs)
Indexing ByteStrings
index :: HasCallStack => ByteString -> Int64 -> Word8 #
O(c) ByteString index (subscript) operator, starting from 0.
This is a partial function, consider using indexMaybe instead.
elemIndex :: Word8 -> ByteString -> Maybe Int64 #
O(n) The elemIndex function returns the index of the first
element in the given ByteString which is equal to the query
element, or Nothing if there is no such element.
This implementation uses memchr(3).
elemIndexEnd :: Word8 -> ByteString -> Maybe Int64 #
O(n) The elemIndexEnd function returns the last index of the
element in the given ByteString which is equal to the query
element, or Nothing if there is no such element. The following
holds:
elemIndexEnd c xs = case elemIndex c (reverse xs) of Nothing -> Nothing Just i -> Just (length xs - 1 - i)
Since: bytestring-0.10.6.0
elemIndices :: Word8 -> ByteString -> [Int64] #
O(n) The elemIndices function extends elemIndex, by returning
the indices of all elements equal to the query element, in ascending order.
This implementation uses memchr(3).
findIndex :: (Word8 -> Bool) -> ByteString -> Maybe Int64 #
The findIndex function takes a predicate and a ByteString and
returns the index of the first element in the ByteString
satisfying the predicate.
findIndices :: (Word8 -> Bool) -> ByteString -> [Int64] #
The findIndices function extends findIndex, by returning the
indices of all elements satisfying the predicate, in ascending order.
count :: Word8 -> ByteString -> Int64 #
count returns the number of times its argument appears in the ByteString
count = length . elemIndices
But more efficiently than using length on the intermediate list.
Zipping and unzipping ByteStrings
zip :: ByteString -> ByteString -> [(Word8, Word8)] #
zipWith :: (Word8 -> Word8 -> a) -> ByteString -> ByteString -> [a] #
unzip :: [(Word8, Word8)] -> (ByteString, ByteString) #
Low level conversions
Copying ByteStrings
copy :: ByteString -> ByteString #
O(n) Make a copy of the ByteString with its own storage.
This is mainly useful to allow the rest of the data pointed
to by the ByteString to be garbage collected, for example
if a large string has been read in, and only a small part of it
is needed in the rest of the program.
I/O with ByteStrings
Standard input and output
getContents :: MonadIO m => m LByteString #
Lifted getContents
putStr :: MonadIO m => LByteString -> m () #
Lifted putStr
putStrLn :: MonadIO m => LByteString -> m () #
Lifted putStrLn
interact :: MonadIO m => (LByteString -> LByteString) -> m () #
Lifted interact
Files
appendFile :: MonadIO m => FilePath -> LByteString -> m () #
Lifted appendFile
I/O with Handles
hGetContents :: MonadIO m => Handle -> m LByteString #
Lifted hGetContents
hGetNonBlocking :: MonadIO m => Handle -> Int -> m LByteString #
Lifted hGetNonBlocking
hPutNonBlocking :: MonadIO m => Handle -> LByteString -> m LByteString #
Lifted hPutNonBlocking