| Copyright | (c) Duncan Coutts 2012-2013 Julian Ospald 2022 |
|---|---|
| License | BSD-style |
| Maintainer | hasufell@posteo.de |
| Stability | stable |
| Portability | ghc only |
| Safe Haskell | Unsafe |
| Language | Haskell2010 |
Data.ByteString.Short.Internal
Description
Internal representation of ShortByteString
Synopsis
- data ShortByteString = SBS ByteArray#
- empty :: ShortByteString
- singleton :: Word8 -> ShortByteString
- pack :: [Word8] -> ShortByteString
- unpack :: ShortByteString -> [Word8]
- fromShort :: ShortByteString -> ByteString
- toShort :: ByteString -> ShortByteString
- snoc :: ShortByteString -> Word8 -> ShortByteString
- cons :: Word8 -> ShortByteString -> ShortByteString
- append :: ShortByteString -> ShortByteString -> ShortByteString
- last :: HasCallStack => ShortByteString -> Word8
- tail :: HasCallStack => ShortByteString -> ShortByteString
- uncons :: ShortByteString -> Maybe (Word8, ShortByteString)
- head :: HasCallStack => ShortByteString -> Word8
- init :: HasCallStack => ShortByteString -> ShortByteString
- unsnoc :: ShortByteString -> Maybe (ShortByteString, Word8)
- null :: ShortByteString -> Bool
- length :: ShortByteString -> Int
- map :: (Word8 -> Word8) -> ShortByteString -> ShortByteString
- reverse :: ShortByteString -> ShortByteString
- intercalate :: ShortByteString -> [ShortByteString] -> ShortByteString
- foldl :: (a -> Word8 -> a) -> a -> ShortByteString -> a
- foldl' :: (a -> Word8 -> a) -> a -> ShortByteString -> a
- foldl1 :: HasCallStack => (Word8 -> Word8 -> Word8) -> ShortByteString -> Word8
- foldl1' :: HasCallStack => (Word8 -> Word8 -> Word8) -> ShortByteString -> Word8
- foldr :: (Word8 -> a -> a) -> a -> ShortByteString -> a
- foldr' :: (Word8 -> a -> a) -> a -> ShortByteString -> a
- foldr1 :: HasCallStack => (Word8 -> Word8 -> Word8) -> ShortByteString -> Word8
- foldr1' :: HasCallStack => (Word8 -> Word8 -> Word8) -> ShortByteString -> Word8
- all :: (Word8 -> Bool) -> ShortByteString -> Bool
- any :: (Word8 -> Bool) -> ShortByteString -> Bool
- concat :: [ShortByteString] -> ShortByteString
- replicate :: Int -> Word8 -> ShortByteString
- unfoldr :: (a -> Maybe (Word8, a)) -> a -> ShortByteString
- unfoldrN :: forall a. Int -> (a -> Maybe (Word8, a)) -> a -> (ShortByteString, Maybe a)
- take :: Int -> ShortByteString -> ShortByteString
- takeEnd :: Int -> ShortByteString -> ShortByteString
- takeWhileEnd :: (Word8 -> Bool) -> ShortByteString -> ShortByteString
- takeWhile :: (Word8 -> Bool) -> ShortByteString -> ShortByteString
- drop :: Int -> ShortByteString -> ShortByteString
- dropEnd :: Int -> ShortByteString -> ShortByteString
- dropWhile :: (Word8 -> Bool) -> ShortByteString -> ShortByteString
- dropWhileEnd :: (Word8 -> Bool) -> ShortByteString -> ShortByteString
- breakEnd :: (Word8 -> Bool) -> ShortByteString -> (ShortByteString, ShortByteString)
- break :: (Word8 -> Bool) -> ShortByteString -> (ShortByteString, ShortByteString)
- span :: (Word8 -> Bool) -> ShortByteString -> (ShortByteString, ShortByteString)
- spanEnd :: (Word8 -> Bool) -> ShortByteString -> (ShortByteString, ShortByteString)
- splitAt :: Int -> ShortByteString -> (ShortByteString, ShortByteString)
- split :: Word8 -> ShortByteString -> [ShortByteString]
- splitWith :: (Word8 -> Bool) -> ShortByteString -> [ShortByteString]
- stripSuffix :: ShortByteString -> ShortByteString -> Maybe ShortByteString
- stripPrefix :: ShortByteString -> ShortByteString -> Maybe ShortByteString
- isInfixOf :: ShortByteString -> ShortByteString -> Bool
- isPrefixOf :: ShortByteString -> ShortByteString -> Bool
- isSuffixOf :: ShortByteString -> ShortByteString -> Bool
- breakSubstring :: ShortByteString -> ShortByteString -> (ShortByteString, ShortByteString)
- elem :: Word8 -> ShortByteString -> Bool
- find :: (Word8 -> Bool) -> ShortByteString -> Maybe Word8
- filter :: (Word8 -> Bool) -> ShortByteString -> ShortByteString
- partition :: (Word8 -> Bool) -> ShortByteString -> (ShortByteString, ShortByteString)
- index :: HasCallStack => ShortByteString -> Int -> Word8
- indexMaybe :: ShortByteString -> Int -> Maybe Word8
- (!?) :: ShortByteString -> Int -> Maybe Word8
- elemIndex :: Word8 -> ShortByteString -> Maybe Int
- elemIndices :: Word8 -> ShortByteString -> [Int]
- count :: Word8 -> ShortByteString -> Int
- findIndex :: (Word8 -> Bool) -> ShortByteString -> Maybe Int
- findIndices :: (Word8 -> Bool) -> ShortByteString -> [Int]
- unsafeIndex :: ShortByteString -> Int -> Word8
- createFromPtr :: Ptr a -> Int -> IO ShortByteString
- copyToPtr :: ShortByteString -> Int -> Ptr a -> Int -> IO ()
- isValidUtf8 :: ShortByteString -> Bool
- packCString :: CString -> IO ShortByteString
- packCStringLen :: CStringLen -> IO ShortByteString
- useAsCString :: ShortByteString -> (CString -> IO a) -> IO a
- useAsCStringLen :: ShortByteString -> (CStringLen -> IO a) -> IO a
The ShortByteString type and representation
data ShortByteString Source #
A compact representation of a Word8 vector.
It has a lower memory overhead than a ByteString and does not
contribute to heap fragmentation. It can be converted to or from a
ByteString (at the cost of copying the string data). It supports very few
other operations.
Constructors
| SBS ByteArray# |
Instances
Introducing and eliminating ShortByteStrings
empty :: ShortByteString Source #
O(1). The empty ShortByteString.
singleton :: Word8 -> ShortByteString Source #
O(1) Convert a Word8 into a ShortByteString
Since: bytestring-0.11.3.0
pack :: [Word8] -> ShortByteString Source #
O(n). Convert a list into a ShortByteString
unpack :: ShortByteString -> [Word8] Source #
O(n). Convert a ShortByteString into a list.
fromShort :: ShortByteString -> ByteString Source #
O(n). Convert a ShortByteString into a ByteString.
toShort :: ByteString -> ShortByteString Source #
O(n). Convert a ByteString into a ShortByteString.
This makes a copy, so does not retain the input string.
Basic interface
snoc :: ShortByteString -> Word8 -> ShortByteString infixl 5 Source #
O(n) Append a byte to the end of a ShortByteString
Note: copies the entire byte array
Since: bytestring-0.11.3.0
cons :: Word8 -> ShortByteString -> ShortByteString infixr 5 Source #
O(n) cons is analogous to (:) for lists.
Note: copies the entire byte array
Since: bytestring-0.11.3.0
last :: HasCallStack => ShortByteString -> Word8 Source #
O(1) Extract the last element of a ShortByteString, which must be finite and non-empty. An exception will be thrown in the case of an empty ShortByteString.
This is a partial function, consider using unsnoc instead.
Since: bytestring-0.11.3.0
tail :: HasCallStack => ShortByteString -> ShortByteString Source #
O(n) Extract the elements after the head of a ShortByteString, which must be non-empty. An exception will be thrown in the case of an empty ShortByteString.
This is a partial function, consider using uncons instead.
Note: copies the entire byte array
Since: bytestring-0.11.3.0
uncons :: ShortByteString -> Maybe (Word8, ShortByteString) Source #
head :: HasCallStack => ShortByteString -> Word8 Source #
O(1) Extract the first element of a ShortByteString, which must be non-empty. An exception will be thrown in the case of an empty ShortByteString.
This is a partial function, consider using uncons instead.
Since: bytestring-0.11.3.0
init :: HasCallStack => ShortByteString -> ShortByteString Source #
O(n) Return all the elements of a ShortByteString except the last one.
An exception will be thrown in the case of an empty ShortByteString.
This is a partial function, consider using unsnoc instead.
Note: copies the entire byte array
Since: bytestring-0.11.3.0
unsnoc :: ShortByteString -> Maybe (ShortByteString, Word8) Source #
null :: ShortByteString -> Bool Source #
O(1) Test whether a ShortByteString is empty.
length :: ShortByteString -> Int Source #
O(1) The length of a ShortByteString.
Transforming ShortByteStrings
map :: (Word8 -> Word8) -> ShortByteString -> ShortByteString Source #
O(n) map f xs is the ShortByteString obtained by applying f to each
element of xs.
Since: bytestring-0.11.3.0
reverse :: ShortByteString -> ShortByteString Source #
O(n) reverse xs efficiently returns the elements of xs in reverse order.
Since: bytestring-0.11.3.0
intercalate :: ShortByteString -> [ShortByteString] -> ShortByteString Source #
O(n) The intercalate function takes a ShortByteString and a list of
ShortByteStrings and concatenates the list after interspersing the first
argument between each element of the list.
Since: bytestring-0.11.3.0
Reducing ShortByteStrings (folds)
foldl :: (a -> Word8 -> a) -> a -> ShortByteString -> a Source #
foldl, applied to a binary operator, a starting value (typically
the left-identity of the operator), and a ShortByteString, reduces the
ShortByteString using the binary operator, from left to right.
Since: bytestring-0.11.3.0
foldl' :: (a -> Word8 -> a) -> a -> ShortByteString -> a Source #
foldl1 :: HasCallStack => (Word8 -> Word8 -> Word8) -> ShortByteString -> Word8 Source #
foldl1 is a variant of foldl that has no starting value
argument, and thus must be applied to non-empty ShortByteStrings.
An exception will be thrown in the case of an empty ShortByteString.
Since: bytestring-0.11.3.0
foldl1' :: HasCallStack => (Word8 -> Word8 -> Word8) -> ShortByteString -> Word8 Source #
foldr :: (Word8 -> a -> a) -> a -> ShortByteString -> a Source #
foldr, applied to a binary operator, a starting value
(typically the right-identity of the operator), and a ShortByteString,
reduces the ShortByteString using the binary operator, from right to left.
Since: bytestring-0.11.3.0
foldr' :: (Word8 -> a -> a) -> a -> ShortByteString -> a Source #
foldr1 :: HasCallStack => (Word8 -> Word8 -> Word8) -> ShortByteString -> Word8 Source #
foldr1 is a variant of foldr that has no starting value argument,
and thus must be applied to non-empty ShortByteStrings
An exception will be thrown in the case of an empty ShortByteString.
Since: bytestring-0.11.3.0
foldr1' :: HasCallStack => (Word8 -> Word8 -> Word8) -> ShortByteString -> Word8 Source #
Special folds
all :: (Word8 -> Bool) -> ShortByteString -> Bool Source #
O(n) Applied to a predicate and a ShortByteString, all determines
if all elements of the ShortByteString satisfy the predicate.
Since: bytestring-0.11.3.0
any :: (Word8 -> Bool) -> ShortByteString -> Bool Source #
O(n) Applied to a predicate and a ShortByteString, any determines if
any element of the ShortByteString satisfies the predicate.
Since: bytestring-0.11.3.0
concat :: [ShortByteString] -> ShortByteString Source #
Generating and unfolding ShortByteStrings
replicate :: Int -> Word8 -> ShortByteString Source #
O(n) replicate n x is a ShortByteString of length n with x
the value of every element. The following holds:
replicate w c = unfoldr w (\u -> Just (u,u)) c
Since: bytestring-0.11.3.0
unfoldr :: (a -> Maybe (Word8, a)) -> a -> ShortByteString Source #
O(n), where n is the length of the result. The unfoldr
function is analogous to the List 'unfoldr'. unfoldr builds a
ShortByteString from a seed value. The function takes the element and
returns Nothing if it is done producing the ShortByteString 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.
This function is not efficient/safe. It will build a list of [Word8]
and run the generator until it returns Nothing, otherwise recurse infinitely,
then finally create a ShortByteString.
If you know the maximum length, consider using unfoldrN.
Examples:
unfoldr (\x -> if x <= 5 then Just (x, x + 1) else Nothing) 0 == pack [0, 1, 2, 3, 4, 5]
Since: bytestring-0.11.3.0
unfoldrN :: forall a. Int -> (a -> Maybe (Word8, a)) -> a -> (ShortByteString, Maybe a) Source #
O(n) Like unfoldr, unfoldrN builds a ShortByteString 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)
Since: bytestring-0.11.3.0
Substrings
Breaking strings
take :: Int -> ShortByteString -> ShortByteString Source #
takeEnd :: Int -> ShortByteString -> ShortByteString Source #
takeWhileEnd :: (Word8 -> Bool) -> ShortByteString -> ShortByteString Source #
Returns the longest (possibly empty) suffix of elements satisfying the predicate.
is equivalent to takeWhileEnd p.reverse . takeWhile p . reverse
Since: bytestring-0.11.3.0
takeWhile :: (Word8 -> Bool) -> ShortByteString -> ShortByteString Source #
Similar to takeWhile,
returns the longest (possibly empty) prefix of elements
satisfying the predicate.
Since: bytestring-0.11.3.0
drop :: Int -> ShortByteString -> ShortByteString Source #
dropEnd :: Int -> ShortByteString -> ShortByteString Source #
dropWhile :: (Word8 -> Bool) -> ShortByteString -> ShortByteString Source #
Similar to dropWhile,
drops the longest (possibly empty) prefix of elements
satisfying the predicate and returns the remainder.
Note: copies the entire byte array
Since: bytestring-0.11.3.0
dropWhileEnd :: (Word8 -> Bool) -> ShortByteString -> ShortByteString Source #
Similar to dropWhileEnd,
drops the longest (possibly empty) suffix of elements
satisfying the predicate and returns the remainder.
is equivalent to dropWhileEnd p.reverse . dropWhile p . reverse
Since: bytestring-0.11.3.0
breakEnd :: (Word8 -> Bool) -> ShortByteString -> (ShortByteString, ShortByteString) Source #
Returns the longest (possibly empty) suffix of elements which do not satisfy the predicate and the remainder of the string.
breakEnd p is equivalent to and to spanEnd (not . p)(.takeWhileEnd (not . p) &&& dropWhileEnd (not . p))
Since: bytestring-0.11.3.0
break :: (Word8 -> Bool) -> ShortByteString -> (ShortByteString, ShortByteString) Source #
span :: (Word8 -> Bool) -> ShortByteString -> (ShortByteString, ShortByteString) Source #
spanEnd :: (Word8 -> Bool) -> ShortByteString -> (ShortByteString, ShortByteString) Source #
Returns the longest (possibly empty) suffix of elements satisfying the predicate and the remainder of the string.
spanEnd p is equivalent to and to breakEnd (not . p)(.takeWhileEnd p &&& dropWhileEnd p)
We have
spanEnd (not . isSpace) "x y z" == ("x y ", "z")and
spanEnd (not . isSpace) sbs == let (x, y) = span (not . isSpace) (reverse sbs) in (reverse y, reverse x)
Since: bytestring-0.11.3.0
splitAt :: Int -> ShortByteString -> (ShortByteString, ShortByteString) Source #
split :: Word8 -> ShortByteString -> [ShortByteString] Source #
O(n) Break a ShortByteString 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 . (==)
Note: copies the substrings
Since: bytestring-0.11.3.0
splitWith :: (Word8 -> Bool) -> ShortByteString -> [ShortByteString] Source #
O(n) Splits a ShortByteString 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 [""]
Since: bytestring-0.11.3.0
stripSuffix :: ShortByteString -> ShortByteString -> Maybe ShortByteString Source #
O(n) The stripSuffix function takes two ShortByteStrings and returns Just
the remainder of the second iff the first is its suffix, and otherwise
Nothing.
Since: bytestring-0.11.3.0
stripPrefix :: ShortByteString -> ShortByteString -> Maybe ShortByteString Source #
O(n) The stripPrefix function takes two ShortByteStrings and returns Just
the remainder of the second iff the first is its prefix, and otherwise
Nothing.
Since: bytestring-0.11.3.0
Predicates
isInfixOf :: ShortByteString -> ShortByteString -> Bool Source #
Check whether one string is a substring of another.
Since: bytestring-0.11.3.0
isPrefixOf :: ShortByteString -> ShortByteString -> Bool Source #
O(n) The isPrefixOf function takes two ShortByteStrings and returns True
Since: bytestring-0.11.3.0
isSuffixOf :: ShortByteString -> ShortByteString -> Bool Source #
O(n) The isSuffixOf function takes two ShortByteStrings and returns True
iff the first is a suffix of the second.
The following holds:
isSuffixOf x y == reverse x `isPrefixOf` reverse y
Since: bytestring-0.11.3.0
Search for arbitrary substrings
Arguments
| :: ShortByteString | String to search for |
| -> ShortByteString | String to search in |
| -> (ShortByteString, ShortByteString) | 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
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 occurrence 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.
Since: bytestring-0.11.3.0
Searching ShortByteStrings
Searching by equality
elem :: Word8 -> ShortByteString -> Bool Source #
O(n) elem is the ShortByteString membership predicate.
Since: bytestring-0.11.3.0
Searching with a predicate
filter :: (Word8 -> Bool) -> ShortByteString -> ShortByteString Source #
O(n) filter, applied to a predicate and a ShortByteString,
returns a ShortByteString containing those characters that satisfy the
predicate.
Since: bytestring-0.11.3.0
partition :: (Word8 -> Bool) -> ShortByteString -> (ShortByteString, ShortByteString) Source #
O(n) The partition function takes a predicate a ShortByteString and returns
the pair of ShortByteStrings with elements which do and do not satisfy the
predicate, respectively; i.e.,
partition p bs == (filter p sbs, filter (not . p) sbs)
Since: bytestring-0.11.3.0
Indexing ShortByteStrings
index :: HasCallStack => ShortByteString -> Int -> Word8 Source #
O(1) ShortByteString index (subscript) operator, starting from 0.
This is a partial function, consider using indexMaybe instead.
indexMaybe :: ShortByteString -> Int -> Maybe Word8 Source #
O(1) ShortByteString index, starting from 0, that returns Just if:
0 <= n < length bs
Since: bytestring-0.11.0.0
(!?) :: ShortByteString -> Int -> Maybe Word8 Source #
O(1) ShortByteString index, starting from 0, that returns Just if:
0 <= n < length bs
Since: bytestring-0.11.0.0
elemIndex :: Word8 -> ShortByteString -> Maybe Int Source #
O(n) The elemIndex function returns the index of the first
element in the given ShortByteString which is equal to the query
element, or Nothing if there is no such element.
Since: bytestring-0.11.3.0
elemIndices :: Word8 -> ShortByteString -> [Int] Source #
O(n) The elemIndices function extends elemIndex, by returning
the indices of all elements equal to the query element, in ascending order.
Since: bytestring-0.11.3.0
count :: Word8 -> ShortByteString -> Int Source #
count returns the number of times its argument appears in the ShortByteString
Since: bytestring-0.11.3.0
findIndex :: (Word8 -> Bool) -> ShortByteString -> Maybe Int Source #
O(n) The findIndex function takes a predicate and a ShortByteString and
returns the index of the first element in the ShortByteString
satisfying the predicate.
Since: bytestring-0.11.3.0
findIndices :: (Word8 -> Bool) -> ShortByteString -> [Int] Source #
O(n) The findIndices function extends findIndex, by returning the
indices of all elements satisfying the predicate, in ascending order.
Since: bytestring-0.11.3.0
unsafeIndex :: ShortByteString -> Int -> Word8 Source #
O(1) Unsafe indexing without bounds checking.
Low level operations
Arguments
| :: Ptr a | source data |
| -> Int | number of bytes to copy |
| -> IO ShortByteString |
Arguments
| :: ShortByteString | source data |
| -> Int | offset into source |
| -> Ptr a | destination |
| -> Int | number of bytes to copy |
| -> IO () |
Encoding validation
isValidUtf8 :: ShortByteString -> Bool Source #
O(n) Check whether a ShortByteString represents valid UTF-8.
Since: bytestring-0.11.3.0
Low level conversions
Packing CStrings and pointers
packCString :: CString -> IO ShortByteString Source #
O(n). Construct a new ShortByteString from a CString. The
resulting ShortByteString is an immutable copy of the original
CString, and is managed on the Haskell heap. The original
CString must be null terminated.
Since: bytestring-0.10.10.0
packCStringLen :: CStringLen -> IO ShortByteString Source #
O(n). Construct a new ShortByteString from a CStringLen. The
resulting ShortByteString is an immutable copy of the original CStringLen.
The ShortByteString is a normal Haskell value and will be managed on the
Haskell heap.
Since: bytestring-0.10.10.0
Using ShortByteStrings as CStrings
useAsCString :: ShortByteString -> (CString -> IO a) -> IO a Source #
O(n) construction. Use a ShortByteString 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.
Since: bytestring-0.10.10.0
useAsCStringLen :: ShortByteString -> (CStringLen -> IO a) -> IO a Source #
O(n) construction. Use a ShortByteString with a function requiring a CStringLen.
As for useAsCString this function makes a copy of the original ShortByteString.
It must not be stored or used after the subcomputation finishes.
Since: bytestring-0.10.10.0