MediaWiki 1.30.2

[autoinstallsdev/mediawiki.git] / includes / libs / ExplodeIterator.php

diff --git a/includes/libs/ExplodeIterator.php b/includes/libs/ExplodeIterator.php
new file mode 100644 (file)
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+++ b/includes/libs/ExplodeIterator.php
@@ -0,0 +1,116 @@
+<?php
+/**
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ * http://www.gnu.org/copyleft/gpl.html
+ *
+ * @file
+ */
+
+/**
+ * An iterator which works exactly like:
+ *
+ * foreach ( explode( $delim, $s ) as $element ) {
+ *    ...
+ * }
+ *
+ * Except it doesn't use 193 byte per element
+ */
+class ExplodeIterator implements Iterator {
+       // The subject string
+       private $subject, $subjectLength;
+
+       // The delimiter
+       private $delim, $delimLength;
+
+       // The position of the start of the line
+       private $curPos;
+
+       // The position after the end of the next delimiter
+       private $endPos;
+
+       /** @var string|false The current token */
+       private $current;
+
+       /**
+        * Construct a DelimIterator
+        * @param string $delim
+        * @param string $subject
+        */
+       public function __construct( $delim, $subject ) {
+               $this->subject = $subject;
+               $this->delim = $delim;
+
+               // Micro-optimisation (theoretical)
+               $this->subjectLength = strlen( $subject );
+               $this->delimLength = strlen( $delim );
+
+               $this->rewind();
+       }
+
+       public function rewind() {
+               $this->curPos = 0;
+               $this->endPos = strpos( $this->subject, $this->delim );
+               $this->refreshCurrent();
+       }
+
+       public function refreshCurrent() {
+               if ( $this->curPos === false ) {
+                       $this->current = false;
+               } elseif ( $this->curPos >= $this->subjectLength ) {
+                       $this->current = '';
+               } elseif ( $this->endPos === false ) {
+                       $this->current = substr( $this->subject, $this->curPos );
+               } else {
+                       $this->current = substr( $this->subject, $this->curPos, $this->endPos - $this->curPos );
+               }
+       }
+
+       public function current() {
+               return $this->current;
+       }
+
+       /**
+        * @return int|bool Current position or boolean false if invalid
+        */
+       public function key() {
+               return $this->curPos;
+       }
+
+       /**
+        * @return string
+        */
+       public function next() {
+               if ( $this->endPos === false ) {
+                       $this->curPos = false;
+               } else {
+                       $this->curPos = $this->endPos + $this->delimLength;
+                       if ( $this->curPos >= $this->subjectLength ) {
+                               $this->endPos = false;
+                       } else {
+                               $this->endPos = strpos( $this->subject, $this->delim, $this->curPos );
+                       }
+               }
+               $this->refreshCurrent();
+
+               return $this->current;
+       }
+
+       /**
+        * @return bool
+        */
+       public function valid() {
+               return $this->curPos !== false;
+       }
+}