RIO.ByteString

Strict ByteString. Import as:

import qualified RIO.ByteString as B

This module does not export any partial functions. For those, see RIO.ByteString.Partial

Documentation

data ByteString

A space-efficient representation of a Word8 vector, supporting many efficient operations.

A ByteString contains 8-bit bytes, or by using the operations from Data.ByteString.Char8 it can be interpreted as containing 8-bit characters.

Instances

Eq ByteString

Defined in Data.ByteString.Internal

Methods

(==) :: ByteString -> ByteString -> Bool

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

Data ByteString

Defined in Data.ByteString.Internal

Methods

gfoldl :: (forall d b. Data d => c (d -> b) -> d -> c b) -> (forall g. g -> c g) -> ByteString -> c ByteString

gunfold :: (forall b r. Data b => c (b -> r) -> c r) -> (forall r. r -> c r) -> Constr -> c ByteString

toConstr :: ByteString -> Constr

dataTypeOf :: ByteString -> DataType

dataCast1 :: Typeable t => (forall d. Data d => c (t d)) -> Maybe (c ByteString)

dataCast2 :: Typeable t => (forall d e. (Data d, Data e) => c (t d e)) -> Maybe (c ByteString)

gmapT :: (forall b. Data b => b -> b) -> ByteString -> ByteString

gmapQl :: (r -> r' -> r) -> r -> (forall d. Data d => d -> r') -> ByteString -> r

gmapQr :: forall r r'. (r' -> r -> r) -> r -> (forall d. Data d => d -> r') -> ByteString -> r

gmapQ :: (forall d. Data d => d -> u) -> ByteString -> [u]

gmapQi :: Int -> (forall d. Data d => d -> u) -> ByteString -> u

gmapM :: Monad m => (forall d. Data d => d -> m d) -> ByteString -> m ByteString

gmapMp :: MonadPlus m => (forall d. Data d => d -> m d) -> ByteString -> m ByteString

gmapMo :: MonadPlus m => (forall d. Data d => d -> m d) -> ByteString -> m ByteString

Ord ByteString

Defined in Data.ByteString.Internal

Methods

compare :: ByteString -> ByteString -> Ordering

(<) :: ByteString -> ByteString -> Bool

(<=) :: ByteString -> ByteString -> Bool

(>) :: ByteString -> ByteString -> Bool

(>=) :: ByteString -> ByteString -> Bool

max :: ByteString -> ByteString -> ByteString

min :: ByteString -> ByteString -> ByteString

Read ByteString

Defined in Data.ByteString.Internal

Methods

readsPrec :: Int -> ReadS ByteString

readList :: ReadS [ByteString]

readPrec :: ReadPrec ByteString

readListPrec :: ReadPrec [ByteString]

Show ByteString

Defined in Data.ByteString.Internal

Methods

showsPrec :: Int -> ByteString -> ShowS

show :: ByteString -> String

showList :: [ByteString] -> ShowS

IsString ByteString

Defined in Data.ByteString.Internal

Methods

fromString :: String -> ByteString

Semigroup ByteString

Defined in Data.ByteString.Internal

Methods

(<>) :: ByteString -> ByteString -> ByteString

sconcat :: NonEmpty ByteString -> ByteString

stimes :: Integral b => b -> ByteString -> ByteString

Monoid ByteString

Defined in Data.ByteString.Internal

Methods

mempty :: ByteString

mappend :: ByteString -> ByteString -> ByteString

mconcat :: [ByteString] -> ByteString

NFData ByteString

Defined in Data.ByteString.Internal

Methods

rnf :: ByteString -> ()

Hashable ByteString

Defined in Data.Hashable.Class

Methods

hashWithSalt :: Int -> ByteString -> Int

hash :: ByteString -> Int

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.

sort :: ByteString -> ByteString

O(n) Sort a ByteString efficiently, using counting sort.

tails :: ByteString -> [ByteString]

O(n) Return all final segments of the given ByteString, longest first.

inits :: ByteString -> [ByteString]

O(n) Return all initial segments of the given ByteString, shortest first.

unzip :: [(Word8, Word8)] -> (ByteString, ByteString)

O(n) unzip transforms a list of pairs of bytes into a pair of ByteStrings. Note that this performs two pack operations.

zipWith :: (Word8 -> Word8 -> a) -> ByteString -> ByteString -> [a]

zipWith generalises zip by zipping with the function given as the first argument, instead of a tupling function. For example, zipWith (+) is applied to two ByteStrings to produce the list of corresponding sums.

zip :: ByteString -> ByteString -> [(Word8, Word8)]

O(n) zip takes two ByteStrings and returns a list of corresponding pairs of bytes. If one input ByteString is short, excess elements of the longer ByteString are discarded. This is equivalent to a pair of unpack operations.

breakSubstring

Arguments

:: ByteString

String to search for

-> ByteString

String to search in

-> (ByteString, ByteString)

Head and tail of string broken at substring

Break a string on a substring, returning a pair of the part of the string prior to the match, and the rest of the string.

The following relationships hold:

break (== c) l == breakSubstring (singleton c) l

and:

findSubstring s l ==
   if null s then Just 0
             else case breakSubstring s l of
                      (x,y) | null y    -> Nothing
                            | otherwise -> Just (length x)

For example, to tokenise a string, dropping delimiters:

tokenise x y = h : if null t then [] else tokenise x (drop (length x) t)
    where (h,t) = breakSubstring x y

To skip to the first occurence of a string:

snd (breakSubstring x y)

To take the parts of a string before a delimiter:

fst (breakSubstring x y)

Note that calling `breakSubstring x` does some preprocessing work, so you should avoid unnecessarily duplicating breakSubstring calls with the same pattern.

isInfixOf :: ByteString -> ByteString -> Bool

Check whether one string is a substring of another. isInfixOf p s is equivalent to not (null (findSubstrings p s)).

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.

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

However, the real implemenation uses memcmp to compare the end of the string only, with no reverse required..

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

isPrefixOf :: ByteString -> ByteString -> Bool

O(n) The isPrefixOf function takes two ByteStrings and returns True if the first is a prefix of the second.

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)

find :: (Word8 -> Bool) -> ByteString -> Maybe Word8

O(n) The find function takes a predicate and a ByteString, and returns the first element in matching the predicate, or Nothing if there is no such element.

find f p = case findIndex f p of Just n -> Just (p ! n) ; _ -> Nothing

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.

notElem :: Word8 -> ByteString -> Bool

O(n) notElem is the inverse of elem

elem :: Word8 -> ByteString -> Bool

O(n) elem is the ByteString membership predicate.

findIndices :: (Word8 -> Bool) -> ByteString -> [Int]

The findIndices function extends findIndex, by returning the indices of all elements satisfying the predicate, in ascending order.

findIndex :: (Word8 -> Bool) -> ByteString -> Maybe Int

The findIndex function takes a predicate and a ByteString and returns the index of the first element in the ByteString satisfying the predicate.

count :: Word8 -> ByteString -> Int

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.

elemIndices :: Word8 -> ByteString -> [Int]

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).

elemIndexEnd :: Word8 -> ByteString -> Maybe Int

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 ==
(-) (length xs - 1) `fmap` elemIndex c (reverse xs)

elemIndex :: Word8 -> ByteString -> Maybe Int

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).

index :: ByteString -> Int -> Word8

O(1) ByteString index (subscript) operator, starting from 0.

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.

groupBy :: (Word8 -> Word8 -> Bool) -> ByteString -> [ByteString]

The groupBy function is the non-overloaded version of group.

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 sublist 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. It is about 40% faster than groupBy (==)

split :: Word8 -> ByteString -> [ByteString]

O(n) Break a ByteString into pieces separated by the byte argument, consuming the delimiter. I.e.

split '\n' "a\nb\nd\ne" == ["a","b","d","e"]
split 'a'  "aXaXaXa"    == ["","X","X","X",""]
split 'x'  "x"          == ["",""]

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 (=='a') "aabbaca" == ["","","bb","c",""]
splitWith (=='a') []        == []

spanEnd :: (Word8 -> Bool) -> ByteString -> (ByteString, ByteString)

spanEnd behaves like span but from the end of the ByteString. We have

spanEnd (not.isSpace) "x y z" == ("x y ","z")

and

spanEnd (not . isSpace) ps
   ==
let (x,y) = span (not.isSpace) (reverse ps) in (reverse y, reverse x)

span :: (Word8 -> Bool) -> ByteString -> (ByteString, ByteString)

span p xs breaks the ByteString into two segments. It is equivalent to (takeWhile p xs, dropWhile p xs)

breakEnd :: (Word8 -> Bool) -> ByteString -> (ByteString, ByteString)

breakEnd behaves like break but from the end of the ByteString

breakEnd p == spanEnd (not.p)

break :: (Word8 -> Bool) -> ByteString -> (ByteString, ByteString)

break p is equivalent to span (not . p).

Under GHC, a rewrite rule will transform break (==) into a call to the specialised breakByte:

break ((==) x) = breakByte x
break (==x) = breakByte x

dropWhile :: (Word8 -> Bool) -> ByteString -> ByteString

dropWhile p xs returns the suffix remaining after takeWhile p xs.

takeWhile :: (Word8 -> Bool) -> ByteString -> ByteString

takeWhile, applied to a predicate p and a ByteString xs, returns the longest prefix (possibly empty) of xs of elements that satisfy p.

splitAt :: Int -> ByteString -> (ByteString, ByteString)

O(1) splitAt n xs is equivalent to (take n xs, drop n xs).

drop :: Int -> ByteString -> ByteString

O(1) drop n xs returns the suffix of xs after the first n elements, or [] if n > length xs.

take :: Int -> ByteString -> ByteString

O(1) take n, applied to a ByteString xs, returns the prefix of xs of length n, or xs itself if n > length xs.

unfoldrN :: Int -> (a -> Maybe (Word8, a)) -> a -> (ByteString, Maybe a)

O(n) Like unfoldr, unfoldrN builds a ByteString from a seed value. However, the length of the result is limited by the first argument to unfoldrN. This function is more efficient than unfoldr when the maximum length of the result is known.

The following equation relates unfoldrN and unfoldr:

fst (unfoldrN n f s) == take n (unfoldr f s)

unfoldr :: (a -> Maybe (Word8, a)) -> a -> ByteString

O(n), where n is the length of the result. 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 the next byte in the string, and b is the seed value for further production.

Examples:

   unfoldr (\x -> if x <= 5 then Just (x, x + 1) else Nothing) 0
== pack [0, 1, 2, 3, 4, 5]

replicate :: Int -> Word8 -> ByteString

O(n) replicate n x is a ByteString of length n with x the value of every element. The following holds:

replicate w c = unfoldr w (\u -> Just (u,u)) c

This implemenation uses memset(3)

scanr1 :: (Word8 -> Word8 -> Word8) -> ByteString -> ByteString

scanr1 is a variant of scanr that has no starting value argument.

scanr :: (Word8 -> Word8 -> Word8) -> Word8 -> ByteString -> ByteString

scanr is the right-to-left dual of scanl.

scanl1 :: (Word8 -> Word8 -> Word8) -> ByteString -> ByteString

scanl1 is a variant of scanl that has no starting value argument. This function will fuse.

scanl1 f [x1, x2, ...] == [x1, x1 `f` x2, ...]

scanl :: (Word8 -> Word8 -> Word8) -> Word8 -> ByteString -> ByteString

scanl is similar to foldl, but returns a list of successive reduced values from the left. This function will fuse.

scanl f z [x1, x2, ...] == [z, z `f` x1, (z `f` x1) `f` x2, ...]

Note that

last (scanl f z xs) == foldl f z xs.

mapAccumR :: (acc -> Word8 -> (acc, Word8)) -> acc -> ByteString -> (acc, ByteString)

The mapAccumR function behaves like a combination of map and foldr; it applies a function to each element of a ByteString, passing an accumulating parameter from right to left, and returning a final value of this accumulator together with the new ByteString.

mapAccumL :: (acc -> Word8 -> (acc, Word8)) -> acc -> ByteString -> (acc, ByteString)

The mapAccumL function behaves like a combination of map and foldl; it applies a function to each element of a ByteString, passing an accumulating parameter from left to right, and returning a final value of this accumulator together with the new list.

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.

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.

concatMap :: (Word8 -> ByteString) -> ByteString -> ByteString

Map a function over a ByteString and concatenate the results

concat :: [ByteString] -> ByteString

O(n) Concatenate a list of ByteStrings.

foldr' :: (Word8 -> a -> a) -> a -> ByteString -> a

foldr' is like foldr, but strict in the accumulator.

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.

foldl' :: (a -> Word8 -> a) -> a -> ByteString -> a

foldl' is like foldl, but strict in the accumulator.

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.

transpose :: [ByteString] -> [ByteString]

The transpose function transposes the rows and columns of its ByteString argument.

intersperse :: Word8 -> ByteString -> ByteString

O(n) 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.

reverse :: ByteString -> ByteString

O(n) reverse xs efficiently returns the elements of xs in reverse order.

map :: (Word8 -> Word8) -> ByteString -> ByteString

O(n) map f xs is the ByteString obtained by applying f to each element of xs.

append :: ByteString -> ByteString -> ByteString

O(n) Append two ByteStrings

unsnoc :: ByteString -> Maybe (ByteString, Word8)

O(1) Extract the init and last of a ByteString, returning Nothing if it is empty.

uncons :: ByteString -> Maybe (Word8, ByteString)

O(1) Extract the head and tail of a ByteString, returning Nothing if it is empty.

snoc :: ByteString -> Word8 -> ByteString infixl 5

O(n) Append a byte to the end of a ByteString

cons :: Word8 -> ByteString -> ByteString infixr 5

O(n) cons is analogous to (:) for lists, but of different complexity, as it requires making a copy.

length :: ByteString -> Int

O(1) length returns the length of a ByteString as an Int.

null :: ByteString -> Bool

O(1) Test whether a ByteString is empty.

unpack :: ByteString -> [Word8]

O(n) Converts a ByteString to a [Word8].

pack :: [Word8] -> ByteString

O(n) Convert a [Word8] into a ByteString.

For applications with large numbers of string literals, pack can be a bottleneck. In such cases, consider using unsafePackAddress (GHC only).

singleton :: Word8 -> ByteString

O(1) Convert a Word8 into a ByteString

empty :: ByteString

O(1) The empty ByteString

packCString :: MonadIO m => CString -> m ByteString

Lifted packCString

packCStringLen :: MonadIO m => CStringLen -> m ByteString

Lifted packCStringLen

useAsCString :: MonadUnliftIO m => ByteString -> (CString -> m a) -> m a

Unlifted useAsCString

useAsCStringLen :: MonadUnliftIO m => ByteString -> (CStringLen -> m a) -> m a

Unlifted useAsCStringLen

getLine :: MonadIO m => m ByteString

Lifted getLine

getContents :: MonadIO m => m ByteString

Lifted getContents

putStr :: MonadIO m => ByteString -> m ()

Lifted putStr

interact :: MonadIO m => (ByteString -> ByteString) -> m ()

Lifted interact

readFile :: MonadIO m => FilePath -> m ByteString

Lifted readFile

writeFile :: MonadIO m => FilePath -> ByteString -> m ()

Lifted writeFile

appendFile :: MonadIO m => FilePath -> ByteString -> m ()

Lifted appendFile

hGetLine :: MonadIO m => Handle -> m ByteString

Lifted hGetLine

hGetContents :: MonadIO m => Handle -> m ByteString

Lifted hGetContents

hGet :: MonadIO m => Handle -> Int -> m ByteString

Lifted hGet

hGetSome :: MonadIO m => Handle -> Int -> m ByteString

Lifted hGetSome

hGetNonBlocking :: MonadIO m => Handle -> Int -> m ByteString

Lifted hGetNonBlocking

hPut :: MonadIO m => Handle -> ByteString -> m ()

Lifted hPut

hPutNonBlocking :: MonadIO m => Handle -> ByteString -> m ByteString

Lifted hPutNonBlocking

hPutStr :: MonadIO m => Handle -> ByteString -> m ()

Lifted hPutStr