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.

It is suitable for use as an internal representation for code that needs to keep many short strings in memory, but it should not be used as an interchange type. That is, it should not generally be used in public APIs. The ByteString type is usually more suitable for use in interfaces; it is more flexible and it supports a wide range of operations.

O(1). The empty ShortByteString.

O(1) Convert a Word16 into a ShortByteString

O(n). Convert a list into a ShortByteString

O(n). Convert a ShortByteString into a list.

O(n). Convert a ShortByteString into a ByteString.

O(n). Convert a ByteString into a ShortByteString.

This makes a copy, so does not retain the input string.

O(n) Append a Word16 to the end of a ShortByteString

Note: copies the entire byte array

O(n) cons is analogous to (:) for lists.

Note: copies the entire byte array

O(1) Extract the last element of a ShortByteString, which must be finite and at least one Word16. An exception will be thrown in the case of an empty ShortByteString.

O(n) Extract the elements after the head of a ShortByteString, which must at least one Word16. An exception will be thrown in the case of an empty ShortByteString.

Note: copies the entire byte array

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

O(1) Extract the first element of a ShortByteString, which must be at least one Word16. An exception will be thrown in the case of an empty ShortByteString.

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.

Note: copies the entire byte array

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

O(1) Test whether a ShortByteString is empty.

O(1) The length of a ShortByteString.

This is like length, but the number of Word16, not Word8.

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

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

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

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.

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

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.

foldl1' is like foldl1, but strict in the accumulator. An exception will be thrown in the case of an empty ShortByteString.

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.

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

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.

foldr1' is a variant of foldr1, but is strict in the accumulator.

O(n) Applied to a predicate and a ShortByteString, all determines if all elements of the ShortByteString satisfy the predicate.

O(n) Applied to a predicate and a ByteString, any determines if any element of the ByteString satisfies the predicate.

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

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 [Word16] and run the generator until it returns Nothing, otherwise recurse infinitely, then finally create a ShortByteString.

Examples:

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

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)

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

Note: copies the entire byte array

O(1) takeEnd n xs is equivalent to drop (length xs - n) xs. Takes n elements from end of bytestring.

>>> takeEnd 3 "a\NULb\NULc\NULd\NULe\NULf\NULg\NUL"
"e\NULf\NULg\NUL"
>>> takeEnd 0 "a\NULb\NULc\NULd\NULe\NULf\NULg\NUL"
""
>>> takeEnd 4 "a\NULb\NULc\NUL"
"a\NULb\NULc\NUL"

Returns the longest (possibly empty) suffix of elements satisfying the predicate.

takeWhileEnd p is equivalent to reverse . takeWhile p . reverse.

Similar to takeWhile, returns the longest (possibly empty) prefix of elements satisfying the predicate.

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

Note: copies the entire byte array

O(1) dropEnd n xs is equivalent to take (length xs - n) xs. Drops n elements from end of bytestring.

>>> dropEnd 3 "a\NULb\NULc\NULd\NULe\NULf\NULg\NUL"
"a\NULb\NULc\NULd\NUL"
>>> dropEnd 0 "a\NULb\NULc\NULd\NULe\NULf\NULg\NUL"
"a\NULb\NULc\NULd\NULe\NULf\NULg\NUL"
>>> dropEnd 4 "a\NULb\NULc\NUL"
""

Similar to dropWhile, drops the longest (possibly empty) prefix of elements satisfying the predicate and returns the remainder.

Note: copies the entire byte array

Similar to dropWhileEnd, drops the longest (possibly empty) suffix of elements satisfying the predicate and returns the remainder.

dropWhileEnd p is equivalent to reverse . dropWhile p . reverse.

Since: 0.10.12.0

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 spanEnd (not . p) and to (takeWhileEnd (not . p) &&& dropWhileEnd (not . p)).

Similar to break, returns the longest (possibly empty) prefix of elements which do not satisfy the predicate and the remainder of the string.

break p is equivalent to span (not . p) and to (takeWhile (not . p) &&& dropWhile (not . p)).

Similar to span, returns the longest (possibly empty) prefix of elements satisfying the predicate and the remainder of the string.

span p is equivalent to break (not . p) and to (takeWhile p &&& dropWhile p).

Returns the longest (possibly empty) suffix of elements satisfying the predicate and the remainder of the string.

spanEnd p is equivalent to breakEnd (not . p) and to (takeWhileEnd p &&& dropWhileEnd p).

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)

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

Note: copies the substrings

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

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 [""]

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

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

Check whether one string is a substring of another.

Since: bytestring-0.11.3.0

O(n) The isPrefixOf function takes two ShortByteStrings and returns True

Since: bytestring-0.11.3.0

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

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

O(n) elem is the ShortByteString membership predicate.

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

O(n) filter, applied to a predicate and a ByteString, returns a ByteString containing those characters that satisfy the predicate.

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)

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

O(1) ShortByteString index, starting from 0, that returns Just if:

0 <= n < length bs

Since: 0.11.0.0

O(1) ShortByteString index, starting from 0, that returns Just if:

0 <= n < length bs

Since: 0.11.0.0

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.

O(n) The elemIndices function extends elemIndex, by returning the indices of all elements equal to the query element, in ascending order.

count returns the number of times its argument appears in the ShortByteString

O(n) The findIndex function takes a predicate and a ShortByteString and returns the index of the first element in the ByteString satisfying the predicate.

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

O(n). Construct a new ShortByteString from a CWString. The resulting ShortByteString is an immutable copy of the original CWString, and is managed on the Haskell heap. The original CWString must be null terminated.

Since: 0.10.10.0

O(n). Construct a new ShortByteString from a CWStringLen. The resulting ShortByteString is an immutable copy of the original CWStringLen. The ShortByteString is a normal Haskell value and will be managed on the Haskell heap.

Since: 0.10.10.0

O(n) construction. Use a ShortByteString with a function requiring a CWStringLen. As for useAsCWString this function makes a copy of the original ShortByteString. It must not be stored or used after the subcomputation finishes.

Since: 0.10.10.0

O(n) construction. Use a ShortByteString with a function requiring a null-terminated CWString. The CWString is a copy and will be freed automatically; it must not be stored or used after the subcomputation finishes.

Since: 0.10.10.0

O(n) construction. Use a ShortByteString with a function requiring a CWStringLen. As for useAsCWString this function makes a copy of the original ShortByteString. It must not be stored or used after the subcomputation finishes.

Since: 0.10.10.0