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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 12:39:39 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 12:39:39 +0000 |
commit | 8ca6cc32b2c789a3149861159ad258f2cb9491e3 (patch) | |
tree | 2492de6f1528dd44eaa169a5c1555026d9cb75ec /library/vendor/HTMLPurifier/Zipper.php | |
parent | Initial commit. (diff) | |
download | icingaweb2-8ca6cc32b2c789a3149861159ad258f2cb9491e3.tar.xz icingaweb2-8ca6cc32b2c789a3149861159ad258f2cb9491e3.zip |
Adding upstream version 2.11.4.upstream/2.11.4upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'library/vendor/HTMLPurifier/Zipper.php')
-rw-r--r-- | library/vendor/HTMLPurifier/Zipper.php | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/library/vendor/HTMLPurifier/Zipper.php b/library/vendor/HTMLPurifier/Zipper.php new file mode 100644 index 0000000..6e21ea0 --- /dev/null +++ b/library/vendor/HTMLPurifier/Zipper.php @@ -0,0 +1,157 @@ +<?php + +/** + * A zipper is a purely-functional data structure which contains + * a focus that can be efficiently manipulated. It is known as + * a "one-hole context". This mutable variant implements a zipper + * for a list as a pair of two arrays, laid out as follows: + * + * Base list: 1 2 3 4 [ ] 6 7 8 9 + * Front list: 1 2 3 4 + * Back list: 9 8 7 6 + * + * User is expected to keep track of the "current element" and properly + * fill it back in as necessary. (ToDo: Maybe it's more user friendly + * to implicitly track the current element?) + * + * Nota bene: the current class gets confused if you try to store NULLs + * in the list. + */ + +class HTMLPurifier_Zipper +{ + public $front, $back; + + public function __construct($front, $back) { + $this->front = $front; + $this->back = $back; + } + + /** + * Creates a zipper from an array, with a hole in the + * 0-index position. + * @param Array to zipper-ify. + * @return Tuple of zipper and element of first position. + */ + static public function fromArray($array) { + $z = new self(array(), array_reverse($array)); + $t = $z->delete(); // delete the "dummy hole" + return array($z, $t); + } + + /** + * Convert zipper back into a normal array, optionally filling in + * the hole with a value. (Usually you should supply a $t, unless you + * are at the end of the array.) + */ + public function toArray($t = NULL) { + $a = $this->front; + if ($t !== NULL) $a[] = $t; + for ($i = count($this->back)-1; $i >= 0; $i--) { + $a[] = $this->back[$i]; + } + return $a; + } + + /** + * Move hole to the next element. + * @param $t Element to fill hole with + * @return Original contents of new hole. + */ + public function next($t) { + if ($t !== NULL) array_push($this->front, $t); + return empty($this->back) ? NULL : array_pop($this->back); + } + + /** + * Iterated hole advancement. + * @param $t Element to fill hole with + * @param $i How many forward to advance hole + * @return Original contents of new hole, i away + */ + public function advance($t, $n) { + for ($i = 0; $i < $n; $i++) { + $t = $this->next($t); + } + return $t; + } + + /** + * Move hole to the previous element + * @param $t Element to fill hole with + * @return Original contents of new hole. + */ + public function prev($t) { + if ($t !== NULL) array_push($this->back, $t); + return empty($this->front) ? NULL : array_pop($this->front); + } + + /** + * Delete contents of current hole, shifting hole to + * next element. + * @return Original contents of new hole. + */ + public function delete() { + return empty($this->back) ? NULL : array_pop($this->back); + } + + /** + * Returns true if we are at the end of the list. + * @return bool + */ + public function done() { + return empty($this->back); + } + + /** + * Insert element before hole. + * @param Element to insert + */ + public function insertBefore($t) { + if ($t !== NULL) array_push($this->front, $t); + } + + /** + * Insert element after hole. + * @param Element to insert + */ + public function insertAfter($t) { + if ($t !== NULL) array_push($this->back, $t); + } + + /** + * Splice in multiple elements at hole. Functional specification + * in terms of array_splice: + * + * $arr1 = $arr; + * $old1 = array_splice($arr1, $i, $delete, $replacement); + * + * list($z, $t) = HTMLPurifier_Zipper::fromArray($arr); + * $t = $z->advance($t, $i); + * list($old2, $t) = $z->splice($t, $delete, $replacement); + * $arr2 = $z->toArray($t); + * + * assert($old1 === $old2); + * assert($arr1 === $arr2); + * + * NB: the absolute index location after this operation is + * *unchanged!* + * + * @param Current contents of hole. + */ + public function splice($t, $delete, $replacement) { + // delete + $old = array(); + $r = $t; + for ($i = $delete; $i > 0; $i--) { + $old[] = $r; + $r = $this->delete(); + } + // insert + for ($i = count($replacement)-1; $i >= 0; $i--) { + $this->insertAfter($r); + $r = $replacement[$i]; + } + return array($old, $r); + } +} |