dropWhileEnd is:exact

The dropWhileEnd function drops the largest suffix of a list in which the given predicate holds for all elements.

Laziness

This function is lazy in spine, but strict in elements, which makes it different from reverse . dropWhile p . reverse, which is strict in spine, but lazy in elements. For instance:

>>> take 1 (dropWhileEnd (< 0) (1 : undefined))
[1]

>>> take 1 (reverse $ dropWhile (< 0) $ reverse (1 : undefined))
*** Exception: Prelude.undefined

but on the other hand

>>> last (dropWhileEnd (< 0) [undefined, 1])
*** Exception: Prelude.undefined

>>> last (reverse $ dropWhile (< 0) $ reverse [undefined, 1])
1

Examples

>>> dropWhileEnd isSpace "foo\n"
"foo"

>>> dropWhileEnd isSpace "foo bar"
"foo bar"

>>> dropWhileEnd (> 10) [1..20]
[1,2,3,4,5,6,7,8,9,10]

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.

dropWhileEnd p xs returns the prefix remaining after takeWhileEnd p xs.

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.

>>> {-# LANGUAGE OverloadedLists #-)

>>> dropWhileEnd even [1,2,3,4,6]
[1,2,3]

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.

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.

O(n) dropWhileEnd p t returns the prefix remaining after dropping characters that satisfy the predicate p from the end of t. Examples:

>>> dropWhileEnd (=='.') "foo..."
"foo"

O(n) dropWhileEnd p t returns the prefix remaining after dropping characters that satisfy the predicate p from the end of t. Examples:

dropWhileEnd (=='.') "foo..." == "foo"

The dropWhileEnd function drops the largest suffix of a list in which the given predicate holds for all elements. For example:

>>> dropWhileEnd isSpace "foo\n"
"foo"

>>> dropWhileEnd isSpace "foo bar"
"foo bar"

dropWhileEnd isSpace ("foo\n" ++ undefined) == "foo" ++ undefined

O(n) dropWhileEnd p t returns the prefix remaining after dropping characters that satisfy the predicate p from the end of t. Subject to fusion. Examples:

>>> dropWhileEnd (=='.') "foo..."
"foo"

Remove longest suffix satisfying given predicate.

dropWhileEnd p t == fst (spanEnd p t)

>>> dropWhileEnd (>= 'c') "abcdabcd"
"abcdab"

O(n) dropWhileEnd p b returns the prefix remaining after dropping characters that satisfy the predicate p from the end of t.

Drops all elements from the end of the list that satisfy the function.

O(n) dropWhileEnd p t returns the prefix remaining after dropping characters that fail the predicate p from the end of t. Subject to fusion. Examples:

dropWhileEnd (=='.') "foo..." == "foo"

As dropWhile but drops from the end instead.

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.

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.

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.

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.