foldr -containers -base
foldr, applied to a binary operator, a starting value (typically the right-identity of the operator), and a packed string, reduces the packed string using the binary operator, from right to left.
O(n) foldr, applied to a binary operator, a starting value (typically the right-identity of the operator), and a Text, reduces the Text using the binary operator, from right to left. Subject to fusion.
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.
'foldr\'' is a strict variant of foldr
'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 ByteStrings
O(n) A variant of foldr that has no starting value argument, and thus must be applied to a non-empty Text. Subject to fusion.
foldr1 is a variant of foldr that has no starting value argument, and thus must be applied to non-empty ByteStrings
foldr1 is a variant of foldr that has no starting value argument, and thus must be applied to non-empty ByteStrings An exception will be thrown in the case of an empty ByteString.
A strict variant of foldr1
'foldr1\'' is a variant of foldr1, but is strict in the accumulator.
Consume the chunks of a lazy Text with a natural right fold.
O(n) 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 a prepending to the ByteString and b is used as the next element in a recursive call.
O(n), 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 character in the string, and b is the seed value for further production.
Examples:
> unfoldr (\x -> if x <= '9' then Just (x, succ x) else Nothing) '0' == "0123456789"
O(n), unfoldr function is analogous to the List unfoldr. unfoldr builds a Text from a seed value. The function takes the element and returns Nothing if it is done producing the Text, otherwise Just (a,b). In this case, a is the next Char in the string, and b is the seed value for further production. Performs replacement on invalid scalar values.
O(n), unfoldr function is analogous to the List unfoldr. unfoldr builds a Text from a seed value. The function takes the element and returns Nothing if it is done producing the Text, otherwise Just (a,b). In this case, a is the next Char in the string, and b is the seed value for further production. Subject to fusion. Performs replacement on invalid scalar values.
O(n) 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 a prepending to the ByteString and b is used as the next element in a recursive call.
O(n), 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]
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:
> unfoldrN n f s == take n (unfoldr f s)
O(n) Like unfoldr, unfoldrN builds a Text from a seed value. However, the length of the result should be limited by the first argument to unfoldrN. This function is more efficient than unfoldr when the maximum length of the result is known and correct, otherwise its performance is similar to unfoldr. Subject to fusion. Performs replacement on invalid scalar values.
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