| Safe Haskell | None |
|---|---|
| Language | Haskell2010 |
ByteString
Contents
Synopsis
- data ByteString
- all :: (Word8 -> Bool) -> ByteString -> Bool
- any :: (Word8 -> Bool) -> ByteString -> Bool
- asHexadecimal :: ByteString -> ByteString
- append :: ByteString -> ByteString -> ByteString
- break :: (Word8 -> Bool) -> ByteString -> (ByteString, ByteString)
- breakEnd :: (Word8 -> Bool) -> ByteString -> (ByteString, ByteString)
- breakSubstring :: ByteString -> ByteString -> (ByteString, ByteString)
- concat :: [ByteString] -> ByteString
- concatMap :: (Word8 -> ByteString) -> ByteString -> ByteString
- cons :: Word8 -> ByteString -> ByteString
- copy :: ByteString -> ByteString
- count :: Word8 -> ByteString -> Int
- drop :: Int -> ByteString -> ByteString
- dropWhile :: (Word8 -> Bool) -> ByteString -> ByteString
- elem :: Word8 -> ByteString -> Bool
- elemIndex :: Word8 -> ByteString -> Maybe Int
- elemIndexEnd :: Word8 -> ByteString -> Maybe Int
- elemIndices :: Word8 -> ByteString -> [Int]
- empty :: ByteString
- filter :: (Word8 -> Bool) -> ByteString -> ByteString
- find :: (Word8 -> Bool) -> ByteString -> Maybe Word8
- findIndex :: (Word8 -> Bool) -> ByteString -> Maybe Int
- findIndices :: (Word8 -> Bool) -> ByteString -> [Int]
- foldl' :: (a -> Word8 -> a) -> a -> ByteString -> a
- foldr :: (Word8 -> a -> a) -> a -> ByteString -> a
- group :: ByteString -> [ByteString]
- groupBy :: (Word8 -> Word8 -> Bool) -> ByteString -> [ByteString]
- index :: ByteString -> Int -> Word8
- inits :: ByteString -> [ByteString]
- intercalate :: ByteString -> [ByteString] -> ByteString
- intersperse :: Word8 -> ByteString -> ByteString
- isInfixOf :: ByteString -> ByteString -> Bool
- isPrefixOf :: ByteString -> ByteString -> Bool
- isSuffixOf :: ByteString -> ByteString -> Bool
- length :: ByteString -> Int
- map :: (Word8 -> Word8) -> ByteString -> ByteString
- mapAccumL :: (acc -> Word8 -> (acc, Word8)) -> acc -> ByteString -> (acc, ByteString)
- mapAccumR :: (acc -> Word8 -> (acc, Word8)) -> acc -> ByteString -> (acc, ByteString)
- notElem :: Word8 -> ByteString -> Bool
- null :: ByteString -> Bool
- pack :: [Word8] -> ByteString
- packCString :: CString -> IO ByteString
- packCStringLen :: CStringLen -> IO ByteString
- partition :: (Word8 -> Bool) -> ByteString -> (ByteString, ByteString)
- replicate :: Int -> Word8 -> ByteString
- reverse :: ByteString -> ByteString
- scanl :: (Word8 -> Word8 -> Word8) -> Word8 -> ByteString -> ByteString
- scanl1 :: (Word8 -> Word8 -> Word8) -> ByteString -> ByteString
- scanr :: (Word8 -> Word8 -> Word8) -> Word8 -> ByteString -> ByteString
- scanr1 :: (Word8 -> Word8 -> Word8) -> ByteString -> ByteString
- singleton :: Word8 -> ByteString
- snoc :: ByteString -> Word8 -> ByteString
- sort :: ByteString -> ByteString
- span :: (Word8 -> Bool) -> ByteString -> (ByteString, ByteString)
- spanEnd :: (Word8 -> Bool) -> ByteString -> (ByteString, ByteString)
- split :: Word8 -> ByteString -> [ByteString]
- splitAt :: Int -> ByteString -> (ByteString, ByteString)
- splitWith :: (Word8 -> Bool) -> ByteString -> [ByteString]
- stripPrefix :: ByteString -> ByteString -> Maybe ByteString
- stripSuffix :: ByteString -> ByteString -> Maybe ByteString
- tails :: ByteString -> [ByteString]
- take :: Int -> ByteString -> ByteString
- takeWhile :: (Word8 -> Bool) -> ByteString -> ByteString
- transpose :: [ByteString] -> [ByteString]
- uncons :: ByteString -> Maybe (Word8, ByteString)
- unfoldr :: (a -> Maybe (Word8, a)) -> a -> ByteString
- unfoldrN :: Int -> (a -> Maybe (Word8, a)) -> a -> (ByteString, Maybe a)
- unpack :: ByteString -> [Word8]
- unsnoc :: ByteString -> Maybe (ByteString, Word8)
- unzip :: [(Word8, Word8)] -> (ByteString, ByteString)
- useAsCString :: ByteString -> (CString -> IO a) -> IO a
- useAsCStringLen :: ByteString -> (CStringLen -> IO a) -> IO a
- zip :: ByteString -> ByteString -> [(Word8, Word8)]
- zipWith :: (Word8 -> Word8 -> a) -> ByteString -> ByteString -> [a]
- bytes :: IsByteString t => IndexedTraversal' Int t Word8
- packedBytes :: IsByteString t => Iso' [Word8] t
- unpackedBytes :: IsByteString t => Iso' t [Word8]
ByteString
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
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.
asHexadecimal :: ByteString -> ByteString #
Convert a bitvector into a lower-case ASCII hexadecimal string. This is helpful for visualizing raw binary data, rather than for parsing as such.
append :: ByteString -> ByteString -> ByteString #
O(n) Append two ByteStrings
break :: (Word8 -> Bool) -> ByteString -> (ByteString, ByteString) #
breakEnd :: (Word8 -> Bool) -> ByteString -> (ByteString, ByteString) #
breakEnd behaves like break but from the end of the ByteString
breakEnd p == spanEnd (not.p)
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 yTo 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.
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
cons :: Word8 -> ByteString -> ByteString infixr 5 #
O(n) cons is analogous to (:) for lists, but of different
complexity, as it requires making a copy.
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.
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.
drop :: Int -> ByteString -> ByteString #
dropWhile :: (Word8 -> Bool) -> ByteString -> ByteString #
elem :: Word8 -> ByteString -> Bool #
O(n) elem is the ByteString membership predicate.
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).
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)
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).
empty :: ByteString #
O(1) The empty ByteString
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.
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.
findIndices :: (Word8 -> Bool) -> ByteString -> [Int] #
The findIndices function extends findIndex, by returning the
indices of all elements satisfying the predicate, in ascending order.
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.
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 (==)
groupBy :: (Word8 -> Word8 -> Bool) -> ByteString -> [ByteString] #
index :: ByteString -> Int -> Word8 #
O(1) ByteString index (subscript) operator, starting from 0.
inits :: ByteString -> [ByteString] #
O(n) Return all initial segments of the given ByteString, shortest first.
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.
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.
isInfixOf :: ByteString -> ByteString -> Bool #
Check whether one string is a substring of another. isInfixOf
p s is equivalent to not (null (findSubstrings p s)).
isPrefixOf :: ByteString -> ByteString -> Bool #
O(n) The isPrefixOf function takes two ByteStrings and returns True
if 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
However, the real implemenation uses memcmp to compare the end of the string only, with no reverse required..
map :: (Word8 -> Word8) -> ByteString -> ByteString #
O(n) map f xs is the ByteString obtained by applying f to each
element of xs.
mapAccumL :: (acc -> Word8 -> (acc, Word8)) -> acc -> ByteString -> (acc, ByteString) #
mapAccumR :: (acc -> Word8 -> (acc, Word8)) -> acc -> ByteString -> (acc, ByteString) #
null :: ByteString -> Bool #
O(1) Test whether a ByteString is empty.
pack :: [Word8] -> ByteString #
O(n) Convert a [ into a Word8]ByteString.
For applications with large numbers of string literals, pack can be a bottleneck. In such cases, consider using packAddress (GHC only).
packCString :: CString -> IO ByteString #
O(n). Construct a new ByteString from a CString. The
resulting ByteString is an immutable copy of the original
CString, and is managed on the Haskell heap. The original
CString must be null terminated.
packCStringLen :: CStringLen -> IO ByteString #
O(n). Construct a new ByteString from a CStringLen. The
resulting ByteString is an immutable copy of the original CStringLen.
The ByteString is a normal Haskell value and will be managed on the
Haskell heap.
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)
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)
reverse :: ByteString -> ByteString #
O(n) reverse xs efficiently returns the elements of xs in reverse order.
scanl :: (Word8 -> Word8 -> Word8) -> Word8 -> ByteString -> ByteString #
scanl1 :: (Word8 -> Word8 -> Word8) -> ByteString -> ByteString #
scanr :: (Word8 -> Word8 -> Word8) -> Word8 -> ByteString -> ByteString #
scanr is the right-to-left dual of scanl.
scanr1 :: (Word8 -> Word8 -> Word8) -> ByteString -> ByteString #
singleton :: Word8 -> ByteString #
O(1) Convert a Word8 into a ByteString
snoc :: ByteString -> Word8 -> ByteString infixl 5 #
O(n) Append a byte to the end of a ByteString
sort :: ByteString -> ByteString #
O(n) Sort a ByteString efficiently, using counting sort.
span :: (Word8 -> Bool) -> ByteString -> (ByteString, ByteString) #
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)
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.
splitAt :: Int -> ByteString -> (ByteString, ByteString) #
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') [] == []
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.
tails :: ByteString -> [ByteString] #
O(n) Return all final segments of the given ByteString, longest first.
take :: Int -> ByteString -> ByteString #
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.
transpose :: [ByteString] -> [ByteString] #
The transpose function transposes the rows and columns of its
ByteString argument.
uncons :: ByteString -> Maybe (Word8, ByteString) #
O(1) Extract the head and tail of a ByteString, returning Nothing if it is empty.
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]
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)
unpack :: ByteString -> [Word8] #
O(n) Converts a ByteString to a [.Word8]
unsnoc :: ByteString -> Maybe (ByteString, Word8) #
unzip :: [(Word8, Word8)] -> (ByteString, ByteString) #
useAsCString :: ByteString -> (CString -> IO a) -> IO a #
O(n) construction Use a ByteString with a function requiring a
null-terminated CString. The CString is a copy and will be freed
automatically; it must not be stored or used after the
subcomputation finishes.
useAsCStringLen :: ByteString -> (CStringLen -> IO a) -> IO a #
O(n) construction Use a ByteString with a function requiring a CStringLen.
As for useAsCString this function makes a copy of the original ByteString.
It must not be stored or used after the subcomputation finishes.
zip :: ByteString -> ByteString -> [(Word8, Word8)] #
zipWith :: (Word8 -> Word8 -> a) -> ByteString -> ByteString -> [a] #
Optics
bytes :: IsByteString t => IndexedTraversal' Int t Word8 #
Traverse each Word8 in a strict or lazy ByteString
This Traversal walks each strict ByteString chunk in a tree-like fashion
enable zippers to seek to locations more quickly and accelerate
many monoidal queries, but up to associativity (and constant factors) it is
equivalent to the much slower:
bytes≡unpackedBytes.traversed
anyOfbytes(==0x80) ::ByteString->Bool
packedBytes :: IsByteString t => Iso' [Word8] t #
pack (or unpack) a list of bytes into a strict or lazy ByteString.
packx ≡ x^.packedBytesunpackx ≡ x^.frompackedBytespackedBytes≡fromunpackedBytes
unpackedBytes :: IsByteString t => Iso' t [Word8] #
unpack (or pack) a ByteString into a list of bytes
unpackedBytes≡frompackedBytesunpackx ≡ x^.unpackedBytespackx ≡ x^.fromunpackedBytes
unpackedBytes::Iso'ByteString[Word8]unpackedBytes::Iso'ByteString[Word8]