Store boolean values as integers with SQLite

[lhc/web/wiklou.git] / includes / MappedIterator.php

diff --git a/includes/MappedIterator.php b/includes/MappedIterator.php
index b4376f4..70d2032 100644 (file)
--- a/includes/MappedIterator.php
+++ b/includes/MappedIterator.php
@@ -26,11 +26,15 @@
  *
  * @since 1.21
  */
-class MappedIterator implements Iterator {
-       /** @var Iterator */
-       protected $baseIterator;
-       /** @var Closure */
+class MappedIterator extends FilterIterator {
+       /** @var callable */
        protected $vCallback;
+       /** @var callable */
+       protected $aCallback;
+       /** @var array */
+       protected $cache = array();
+
+       protected $rewound = false; // boolean; whether rewind() has been called
 
        /**
         * Build an new iterator from a base iterator by having the former wrap the
@@ -38,59 +42,73 @@ class MappedIterator implements Iterator {
         * The callback takes the result of current() on the base iterator as an argument.
         * The keys of the base iterator are reused verbatim.
         *
+        * An "accept" callback can also be provided which will be called for each value in
+        * the base iterator (post-callback) and will return true if that value should be
+        * included in iteration of the MappedIterator (otherwise it will be filtered out).
+        *
         * @param Iterator|Array $iter
-        * @param Closure $vCallback
+        * @param callable $vCallback Value transformation callback
+        * @param array $options Options map (includes "accept") (since 1.22)
         * @throws MWException
         */
-    public function __construct( $iter, Closure $vCallback ) {
+       public function __construct( $iter, $vCallback, array $options = array() ) {
                if ( is_array( $iter ) ) {
-                       $this->baseIterator = new ArrayIterator( $iter );
+                       $baseIterator = new ArrayIterator( $iter );
                } elseif ( $iter instanceof Iterator ) {
-                       $this->baseIterator = $iter;
+                       $baseIterator = $iter;
                } else {
                        throw new MWException( "Invalid base iterator provided." );
                }
+               parent::__construct( $baseIterator );
                $this->vCallback = $vCallback;
-    }
+               $this->aCallback = isset( $options['accept'] ) ? $options['accept'] : null;
+       }
+
+       public function next() {
+               $this->cache = array();
+               parent::next();
+       }
 
-       /**
-        * @return void
-        */
        public function rewind() {
-               $this->baseIterator->rewind();
+               $this->rewound = true;
+               $this->cache = array();
+               parent::rewind();
        }
 
-       /**
-        * @return Mixed|null Returns null if out of range
-        */
-       public function current() {
-               if ( !$this->baseIterator->valid() ) {
-                       return null; // out of range
+       public function accept() {
+               $value = call_user_func( $this->vCallback, $this->getInnerIterator()->current() );
+               $ok = ( $this->aCallback ) ? call_user_func( $this->aCallback, $value ) : true;
+               if ( $ok ) {
+                       $this->cache['current'] = $value;
                }
-               return call_user_func_array( $this->vCallback, array( $this->baseIterator->current() ) );
+               return $ok;
        }
 
-       /**
-        * @return Mixed|null Returns null if out of range
-        */
        public function key() {
-               if ( !$this->baseIterator->valid() ) {
-                       return null; // out of range
-               }
-               return $this->baseIterator->key();
+               $this->init();
+               return parent::key();
        }
 
-       /**
-        * @return void
-        */
-       public function next() {
-               $this->baseIterator->next();
+       public function valid() {
+               $this->init();
+               return parent::valid();
+       }
+
+       public function current() {
+               $this->init();
+               if ( parent::valid() ) {
+                       return $this->cache['current'];
+               } else {
+                       return null; // out of range
+               }
        }
 
        /**
-        * @return bool
+        * Obviate the usual need for rewind() before using a FilterIterator in a manual loop
         */
-       public function valid() {
-               return $this->baseIterator->valid();
+       protected function init() {
+               if ( !$this->rewound ) {
+                       $this->rewind();
+               }
        }
 }