3 * Convenience class for generating iterators from iterators.
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6 * it under the terms of the GNU General Public License as published by
7 * the Free Software Foundation; either version 2 of the License, or
8 * (at your option) any later version.
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
15 * You should have received a copy of the GNU General Public License along
16 * with this program; if not, write to the Free Software Foundation, Inc.,
17 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
18 * http://www.gnu.org/copyleft/gpl.html
24 * Convenience class for generating iterators from iterators.
28 class MappedIterator
extends FilterIterator
{
34 protected $cache = [];
36 protected $rewound = false; // boolean; whether rewind() has been called
39 * Build an new iterator from a base iterator by having the former wrap the
40 * later, returning the result of "value" callback for each current() invocation.
41 * The callback takes the result of current() on the base iterator as an argument.
42 * The keys of the base iterator are reused verbatim.
44 * An "accept" callback can also be provided which will be called for each value in
45 * the base iterator (post-callback) and will return true if that value should be
46 * included in iteration of the MappedIterator (otherwise it will be filtered out).
48 * @param Iterator|array $iter
49 * @param callable $vCallback Value transformation callback
50 * @param array $options Options map (includes "accept") (since 1.22)
51 * @phan-param array{accept?:callable} $options
52 * @throws UnexpectedValueException
54 public function __construct( $iter, $vCallback, array $options = [] ) {
55 if ( is_array( $iter ) ) {
56 $baseIterator = new ArrayIterator( $iter );
57 } elseif ( $iter instanceof Iterator
) {
58 $baseIterator = $iter;
60 throw new UnexpectedValueException( "Invalid base iterator provided." );
62 parent
::__construct( $baseIterator );
63 $this->vCallback
= $vCallback;
64 // @phan-suppress-next-line PhanTypeInvalidDimOffset
65 $this->aCallback
= $options['accept'] ??
null;
68 public function next() {
73 public function rewind() {
74 $this->rewound
= true;
79 public function accept() {
80 $value = call_user_func( $this->vCallback
, $this->getInnerIterator()->current() );
81 $ok = ( $this->aCallback
) ?
call_user_func( $this->aCallback
, $value ) : true;
83 $this->cache
['current'] = $value;
89 public function key() {
95 public function valid() {
98 return parent
::valid();
101 public function current() {
103 if ( parent
::valid() ) {
104 return $this->cache
['current'];
106 return null; // out of range
111 * Obviate the usual need for rewind() before using a FilterIterator in a manual loop
113 protected function init() {
114 if ( !$this->rewound
) {