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 |
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 :: 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.
Instances
Introducing and eliminating ShortByteString
s
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
ShortByteString
s and concatenates the list after interspersing the first
argument between each element of the list.
Since: bytestring-0.11.3.0
Reducing ShortByteString
s (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 ShortByteString
s.
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 ShortByteString
s
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 :: 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
:: 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 y
To 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
:: Ptr a | source data |
-> Int | number of bytes to copy |
-> IO ShortByteString |
:: 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 CString
s 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 CString
s
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